multi_buffer_tests.rs

   1use super::*;
   2use buffer_diff::{DiffHunkStatus, DiffHunkStatusKind};
   3use gpui::{App, TestAppContext};
   4use indoc::indoc;
   5use language::{Buffer, Rope};
   6use parking_lot::RwLock;
   7use rand::prelude::*;
   8use settings::SettingsStore;
   9use std::env;
  10use std::time::{Duration, Instant};
  11use util::RandomCharIter;
  12use util::rel_path::rel_path;
  13use util::test::sample_text;
  14
  15#[ctor::ctor]
  16fn init_logger() {
  17    zlog::init_test();
  18}
  19
  20#[gpui::test]
  21fn test_empty_singleton(cx: &mut App) {
  22    let buffer = cx.new(|cx| Buffer::local("", cx));
  23    let buffer_id = buffer.read(cx).remote_id();
  24    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
  25    let snapshot = multibuffer.read(cx).snapshot(cx);
  26    assert_eq!(snapshot.text(), "");
  27    assert_eq!(
  28        snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>(),
  29        [RowInfo {
  30            buffer_id: Some(buffer_id),
  31            buffer_row: Some(0),
  32            multibuffer_row: Some(MultiBufferRow(0)),
  33            diff_status: None,
  34            expand_info: None,
  35            wrapped_buffer_row: None,
  36        }]
  37    );
  38}
  39
  40#[gpui::test]
  41fn test_singleton(cx: &mut App) {
  42    let buffer = cx.new(|cx| Buffer::local(sample_text(6, 6, 'a'), cx));
  43    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
  44
  45    let snapshot = multibuffer.read(cx).snapshot(cx);
  46    assert_eq!(snapshot.text(), buffer.read(cx).text());
  47
  48    assert_eq!(
  49        snapshot
  50            .row_infos(MultiBufferRow(0))
  51            .map(|info| info.buffer_row)
  52            .collect::<Vec<_>>(),
  53        (0..buffer.read(cx).row_count())
  54            .map(Some)
  55            .collect::<Vec<_>>()
  56    );
  57    assert_consistent_line_numbers(&snapshot);
  58
  59    buffer.update(cx, |buffer, cx| buffer.edit([(1..3, "XXX\n")], None, cx));
  60    let snapshot = multibuffer.read(cx).snapshot(cx);
  61
  62    assert_eq!(snapshot.text(), buffer.read(cx).text());
  63    assert_eq!(
  64        snapshot
  65            .row_infos(MultiBufferRow(0))
  66            .map(|info| info.buffer_row)
  67            .collect::<Vec<_>>(),
  68        (0..buffer.read(cx).row_count())
  69            .map(Some)
  70            .collect::<Vec<_>>()
  71    );
  72    assert_consistent_line_numbers(&snapshot);
  73}
  74
  75#[gpui::test]
  76fn test_remote(cx: &mut App) {
  77    let host_buffer = cx.new(|cx| Buffer::local("a", cx));
  78    let guest_buffer = cx.new(|cx| {
  79        let state = host_buffer.read(cx).to_proto(cx);
  80        let ops = cx
  81            .foreground_executor()
  82            .block_on(host_buffer.read(cx).serialize_ops(None, cx));
  83        let mut buffer =
  84            Buffer::from_proto(ReplicaId::REMOTE_SERVER, Capability::ReadWrite, state, None)
  85                .unwrap();
  86        buffer.apply_ops(
  87            ops.into_iter()
  88                .map(|op| language::proto::deserialize_operation(op).unwrap()),
  89            cx,
  90        );
  91        buffer
  92    });
  93    let multibuffer = cx.new(|cx| MultiBuffer::singleton(guest_buffer.clone(), cx));
  94    let snapshot = multibuffer.read(cx).snapshot(cx);
  95    assert_eq!(snapshot.text(), "a");
  96
  97    guest_buffer.update(cx, |buffer, cx| buffer.edit([(1..1, "b")], None, cx));
  98    let snapshot = multibuffer.read(cx).snapshot(cx);
  99    assert_eq!(snapshot.text(), "ab");
 100
 101    guest_buffer.update(cx, |buffer, cx| buffer.edit([(2..2, "c")], None, cx));
 102    let snapshot = multibuffer.read(cx).snapshot(cx);
 103    assert_eq!(snapshot.text(), "abc");
 104}
 105
 106#[gpui::test]
 107fn test_excerpt_boundaries_and_clipping(cx: &mut App) {
 108    let buffer_1 = cx.new(|cx| Buffer::local(sample_text(7, 6, 'a'), cx));
 109    let buffer_2 = cx.new(|cx| Buffer::local(sample_text(7, 6, 'g'), cx));
 110    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
 111
 112    let events = Arc::new(RwLock::new(Vec::<Event>::new()));
 113    multibuffer.update(cx, |_, cx| {
 114        let events = events.clone();
 115        cx.subscribe(&multibuffer, move |_, _, event, _| {
 116            if let Event::Edited { .. } = event {
 117                events.write().push(event.clone())
 118            }
 119        })
 120        .detach();
 121    });
 122
 123    let subscription = multibuffer.update(cx, |multibuffer, cx| {
 124        let subscription = multibuffer.subscribe();
 125        multibuffer.set_excerpt_ranges_for_path(
 126            PathKey::sorted(0),
 127            buffer_1.clone(),
 128            &buffer_1.read(cx).snapshot(),
 129            vec![ExcerptRange::new(Point::new(1, 2)..Point::new(2, 5))],
 130            cx,
 131        );
 132        assert_eq!(
 133            subscription.consume().into_inner(),
 134            [Edit {
 135                old: MultiBufferOffset(0)..MultiBufferOffset(0),
 136                new: MultiBufferOffset(0)..MultiBufferOffset(10)
 137            }]
 138        );
 139
 140        multibuffer.set_excerpt_ranges_for_path(
 141            PathKey::sorted(0),
 142            buffer_1.clone(),
 143            &buffer_1.read(cx).snapshot(),
 144            vec![
 145                ExcerptRange::new(Point::new(1, 2)..Point::new(2, 5)),
 146                ExcerptRange::new(Point::new(5, 3)..Point::new(6, 4)),
 147            ],
 148            cx,
 149        );
 150        multibuffer.set_excerpt_ranges_for_path(
 151            PathKey::sorted(1),
 152            buffer_2.clone(),
 153            &buffer_2.read(cx).snapshot(),
 154            vec![ExcerptRange::new(Point::new(3, 1)..Point::new(3, 3))],
 155            cx,
 156        );
 157        assert_eq!(
 158            subscription.consume().into_inner(),
 159            [Edit {
 160                old: MultiBufferOffset(10)..MultiBufferOffset(10),
 161                new: MultiBufferOffset(10)..MultiBufferOffset(22)
 162            }]
 163        );
 164
 165        subscription
 166    });
 167
 168    // Adding excerpts emits an edited event.
 169    assert_eq!(
 170        events.read().as_slice(),
 171        &[
 172            Event::Edited {
 173                edited_buffer: None,
 174            },
 175            Event::Edited {
 176                edited_buffer: None,
 177            },
 178            Event::Edited {
 179                edited_buffer: None,
 180            }
 181        ]
 182    );
 183
 184    let snapshot = multibuffer.read(cx).snapshot(cx);
 185    assert_eq!(
 186        snapshot.text(),
 187        indoc!(
 188            "
 189            bbbb
 190            ccccc
 191            fff
 192            gggg
 193            jj"
 194        ),
 195    );
 196    assert_eq!(
 197        snapshot
 198            .row_infos(MultiBufferRow(0))
 199            .map(|info| info.buffer_row)
 200            .collect::<Vec<_>>(),
 201        [Some(1), Some(2), Some(5), Some(6), Some(3)]
 202    );
 203    assert_eq!(
 204        snapshot
 205            .row_infos(MultiBufferRow(2))
 206            .map(|info| info.buffer_row)
 207            .collect::<Vec<_>>(),
 208        [Some(5), Some(6), Some(3)]
 209    );
 210    assert_eq!(
 211        snapshot
 212            .row_infos(MultiBufferRow(4))
 213            .map(|info| info.buffer_row)
 214            .collect::<Vec<_>>(),
 215        [Some(3)]
 216    );
 217    assert!(
 218        snapshot
 219            .row_infos(MultiBufferRow(5))
 220            .map(|info| info.buffer_row)
 221            .collect::<Vec<_>>()
 222            .is_empty()
 223    );
 224
 225    assert_eq!(
 226        boundaries_in_range(Point::new(0, 0)..Point::new(4, 2), &snapshot),
 227        &[
 228            (MultiBufferRow(0), "bbbb\nccccc".to_string(), true),
 229            (MultiBufferRow(2), "fff\ngggg".to_string(), false),
 230            (MultiBufferRow(4), "jj".to_string(), true),
 231        ]
 232    );
 233    assert_eq!(
 234        boundaries_in_range(Point::new(0, 0)..Point::new(2, 0), &snapshot),
 235        &[(MultiBufferRow(0), "bbbb\nccccc".to_string(), true)]
 236    );
 237    assert_eq!(
 238        boundaries_in_range(Point::new(1, 0)..Point::new(1, 5), &snapshot),
 239        &[]
 240    );
 241    assert_eq!(
 242        boundaries_in_range(Point::new(1, 0)..Point::new(2, 0), &snapshot),
 243        &[]
 244    );
 245    assert_eq!(
 246        boundaries_in_range(Point::new(1, 0)..Point::new(4, 0), &snapshot),
 247        &[(MultiBufferRow(2), "fff\ngggg".to_string(), false)]
 248    );
 249    assert_eq!(
 250        boundaries_in_range(Point::new(1, 0)..Point::new(4, 0), &snapshot),
 251        &[(MultiBufferRow(2), "fff\ngggg".to_string(), false)]
 252    );
 253    assert_eq!(
 254        boundaries_in_range(Point::new(2, 0)..Point::new(3, 0), &snapshot),
 255        &[(MultiBufferRow(2), "fff\ngggg".to_string(), false)]
 256    );
 257    assert_eq!(
 258        boundaries_in_range(Point::new(4, 0)..Point::new(4, 2), &snapshot),
 259        &[(MultiBufferRow(4), "jj".to_string(), true)]
 260    );
 261    assert_eq!(
 262        boundaries_in_range(Point::new(4, 2)..Point::new(4, 2), &snapshot),
 263        &[]
 264    );
 265
 266    buffer_1.update(cx, |buffer, cx| {
 267        let text = "\n";
 268        buffer.edit(
 269            [
 270                (Point::new(0, 0)..Point::new(0, 0), text),
 271                (Point::new(2, 1)..Point::new(2, 3), text),
 272            ],
 273            None,
 274            cx,
 275        );
 276    });
 277
 278    let snapshot = multibuffer.read(cx).snapshot(cx);
 279    assert_eq!(
 280        snapshot.text(),
 281        concat!(
 282            "bbbb\n", // Preserve newlines
 283            "c\n",    //
 284            "cc\n",   //
 285            "fff\n",  //
 286            "gggg\n", //
 287            "jj"      //
 288        )
 289    );
 290
 291    assert_eq!(
 292        subscription.consume().into_inner(),
 293        [Edit {
 294            old: MultiBufferOffset(6)..MultiBufferOffset(8),
 295            new: MultiBufferOffset(6)..MultiBufferOffset(7)
 296        }]
 297    );
 298
 299    let snapshot = multibuffer.read(cx).snapshot(cx);
 300    assert_eq!(
 301        snapshot.clip_point(Point::new(0, 5), Bias::Left),
 302        Point::new(0, 4)
 303    );
 304    assert_eq!(
 305        snapshot.clip_point(Point::new(0, 5), Bias::Right),
 306        Point::new(0, 4)
 307    );
 308    assert_eq!(
 309        snapshot.clip_point(Point::new(5, 1), Bias::Right),
 310        Point::new(5, 1)
 311    );
 312    assert_eq!(
 313        snapshot.clip_point(Point::new(5, 2), Bias::Right),
 314        Point::new(5, 2)
 315    );
 316    assert_eq!(
 317        snapshot.clip_point(Point::new(5, 3), Bias::Right),
 318        Point::new(5, 2)
 319    );
 320
 321    let snapshot = multibuffer.update(cx, |multibuffer, cx| {
 322        multibuffer.remove_excerpts_for_path(PathKey::sorted(1), cx);
 323        multibuffer.snapshot(cx)
 324    });
 325
 326    assert_eq!(
 327        snapshot.text(),
 328        concat!(
 329            "bbbb\n", // Preserve newlines
 330            "c\n",    //
 331            "cc\n",   //
 332            "fff\n",  //
 333            "gggg",   //
 334        )
 335    );
 336
 337    fn boundaries_in_range(
 338        range: Range<Point>,
 339        snapshot: &MultiBufferSnapshot,
 340    ) -> Vec<(MultiBufferRow, String, bool)> {
 341        snapshot
 342            .excerpt_boundaries_in_range(range)
 343            .map(|boundary| {
 344                let starts_new_buffer = boundary.starts_new_buffer();
 345                (
 346                    boundary.row,
 347                    boundary
 348                        .next
 349                        .buffer
 350                        .text_for_range(boundary.next.range.context)
 351                        .collect::<String>(),
 352                    starts_new_buffer,
 353                )
 354            })
 355            .collect::<Vec<_>>()
 356    }
 357}
 358
 359#[gpui::test]
 360async fn test_diff_boundary_anchors(cx: &mut TestAppContext) {
 361    let base_text = "one\ntwo\nthree\n";
 362    let text = "one\nthree\n";
 363    let buffer = cx.new(|cx| Buffer::local(text, cx));
 364    let diff = cx
 365        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
 366    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
 367    multibuffer.update(cx, |multibuffer, cx| multibuffer.add_diff(diff, cx));
 368
 369    let (before, after) = multibuffer.update(cx, |multibuffer, cx| {
 370        let before = multibuffer.snapshot(cx).anchor_before(Point::new(1, 0));
 371        let after = multibuffer.snapshot(cx).anchor_after(Point::new(1, 0));
 372        multibuffer.set_all_diff_hunks_expanded(cx);
 373        (before, after)
 374    });
 375    cx.run_until_parked();
 376
 377    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
 378    let actual_text = snapshot.text();
 379    let actual_row_infos = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
 380    let actual_diff = format_diff(&actual_text, &actual_row_infos, &Default::default(), None);
 381    pretty_assertions::assert_eq!(
 382        actual_diff,
 383        indoc! {
 384            "  one
 385             - two
 386               three
 387             "
 388        },
 389    );
 390
 391    multibuffer.update(cx, |multibuffer, cx| {
 392        let snapshot = multibuffer.snapshot(cx);
 393        assert_eq!(before.to_point(&snapshot), Point::new(1, 0));
 394        assert_eq!(after.to_point(&snapshot), Point::new(2, 0));
 395        assert_eq!(
 396            vec![Point::new(1, 0), Point::new(2, 0),],
 397            snapshot.summaries_for_anchors::<Point, _>(&[before, after]),
 398        )
 399    })
 400}
 401
 402#[gpui::test]
 403async fn test_diff_hunks_in_range(cx: &mut TestAppContext) {
 404    let base_text = "one\ntwo\nthree\nfour\nfive\nsix\nseven\neight\n";
 405    let text = "one\nfour\nseven\n";
 406    let buffer = cx.new(|cx| Buffer::local(text, cx));
 407    let diff = cx
 408        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
 409    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
 410    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
 411        (multibuffer.snapshot(cx), multibuffer.subscribe())
 412    });
 413
 414    multibuffer.update(cx, |multibuffer, cx| {
 415        multibuffer.add_diff(diff, cx);
 416        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
 417    });
 418
 419    assert_new_snapshot(
 420        &multibuffer,
 421        &mut snapshot,
 422        &mut subscription,
 423        cx,
 424        indoc! {
 425            "  one
 426             - two
 427             - three
 428               four
 429             - five
 430             - six
 431               seven
 432             - eight
 433            "
 434        },
 435    );
 436
 437    assert_eq!(
 438        snapshot
 439            .diff_hunks_in_range(Point::new(1, 0)..Point::MAX)
 440            .map(|hunk| hunk.row_range.start.0..hunk.row_range.end.0)
 441            .collect::<Vec<_>>(),
 442        vec![1..3, 4..6, 7..8]
 443    );
 444
 445    assert_eq!(snapshot.diff_hunk_before(Point::new(1, 1)), None,);
 446    assert_eq!(
 447        snapshot.diff_hunk_before(Point::new(7, 0)),
 448        Some(MultiBufferRow(4))
 449    );
 450    assert_eq!(
 451        snapshot.diff_hunk_before(Point::new(4, 0)),
 452        Some(MultiBufferRow(1))
 453    );
 454
 455    multibuffer.update(cx, |multibuffer, cx| {
 456        multibuffer.collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
 457    });
 458
 459    assert_new_snapshot(
 460        &multibuffer,
 461        &mut snapshot,
 462        &mut subscription,
 463        cx,
 464        indoc! {
 465            "
 466            one
 467            four
 468            seven
 469            "
 470        },
 471    );
 472
 473    assert_eq!(
 474        snapshot.diff_hunk_before(Point::new(2, 0)),
 475        Some(MultiBufferRow(1)),
 476    );
 477    assert_eq!(
 478        snapshot.diff_hunk_before(Point::new(4, 0)),
 479        Some(MultiBufferRow(2))
 480    );
 481}
 482
 483#[gpui::test]
 484async fn test_diff_hunks_in_range_query_starting_at_added_row(cx: &mut TestAppContext) {
 485    let base_text = "one\ntwo\nthree\n";
 486    let text = "one\nTWO\nthree\n";
 487    let buffer = cx.new(|cx| Buffer::local(text, cx));
 488    let diff = cx
 489        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
 490    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
 491    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
 492        (multibuffer.snapshot(cx), multibuffer.subscribe())
 493    });
 494
 495    multibuffer.update(cx, |multibuffer, cx| {
 496        multibuffer.add_diff(diff, cx);
 497        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
 498    });
 499
 500    assert_new_snapshot(
 501        &multibuffer,
 502        &mut snapshot,
 503        &mut subscription,
 504        cx,
 505        indoc! {
 506            "  one
 507             - two
 508             + TWO
 509               three
 510            "
 511        },
 512    );
 513
 514    assert_eq!(
 515        snapshot
 516            .diff_hunks_in_range(Point::new(2, 0)..Point::MAX)
 517            .map(|hunk| hunk.row_range.start.0..hunk.row_range.end.0)
 518            .collect::<Vec<_>>(),
 519        vec![1..3],
 520        "querying starting at the added row should still return the full hunk including deleted lines"
 521    );
 522}
 523
 524#[gpui::test]
 525async fn test_inverted_diff_hunks_in_range(cx: &mut TestAppContext) {
 526    let base_text = "one\ntwo\nthree\nfour\nfive\nsix\nseven\neight\n";
 527    let text = "ZERO\none\nTHREE\nfour\nseven\nEIGHT\nNINE\n";
 528    let buffer = cx.new(|cx| Buffer::local(text, cx));
 529    let diff = cx
 530        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
 531    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
 532    let multibuffer = cx.new(|cx| MultiBuffer::singleton(base_text_buffer.clone(), cx));
 533    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
 534        (multibuffer.snapshot(cx), multibuffer.subscribe())
 535    });
 536
 537    multibuffer.update(cx, |multibuffer, cx| {
 538        multibuffer.add_inverted_diff(diff, buffer.clone(), cx);
 539    });
 540
 541    assert_new_snapshot(
 542        &multibuffer,
 543        &mut snapshot,
 544        &mut subscription,
 545        cx,
 546        indoc! {
 547            "  one
 548             - two
 549             - three
 550               four
 551             - five
 552             - six
 553               seven
 554             - eight
 555            "
 556        },
 557    );
 558
 559    assert_eq!(
 560        snapshot
 561            .diff_hunks_in_range(Point::new(0, 0)..Point::MAX)
 562            .map(|hunk| hunk.row_range.start.0..hunk.row_range.end.0)
 563            .collect::<Vec<_>>(),
 564        vec![0..0, 1..3, 4..6, 7..8]
 565    );
 566
 567    assert_eq!(
 568        snapshot.diff_hunk_before(Point::new(1, 1)),
 569        Some(MultiBufferRow(0))
 570    );
 571    assert_eq!(
 572        snapshot.diff_hunk_before(Point::new(7, 0)),
 573        Some(MultiBufferRow(4))
 574    );
 575    assert_eq!(
 576        snapshot.diff_hunk_before(Point::new(4, 0)),
 577        Some(MultiBufferRow(1))
 578    );
 579}
 580
 581#[gpui::test]
 582async fn test_editing_text_in_diff_hunks(cx: &mut TestAppContext) {
 583    let base_text = "one\ntwo\nfour\nfive\nsix\nseven\n";
 584    let text = "one\ntwo\nTHREE\nfour\nfive\nseven\n";
 585    let buffer = cx.new(|cx| Buffer::local(text, cx));
 586    let diff = cx
 587        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
 588    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
 589
 590    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
 591        multibuffer.add_diff(diff.clone(), cx);
 592        (multibuffer.snapshot(cx), multibuffer.subscribe())
 593    });
 594
 595    cx.executor().run_until_parked();
 596    multibuffer.update(cx, |multibuffer, cx| {
 597        multibuffer.set_all_diff_hunks_expanded(cx);
 598    });
 599
 600    assert_new_snapshot(
 601        &multibuffer,
 602        &mut snapshot,
 603        &mut subscription,
 604        cx,
 605        indoc! {
 606            "
 607              one
 608              two
 609            + THREE
 610              four
 611              five
 612            - six
 613              seven
 614            "
 615        },
 616    );
 617
 618    // Insert a newline within an insertion hunk
 619    multibuffer.update(cx, |multibuffer, cx| {
 620        multibuffer.edit([(Point::new(2, 0)..Point::new(2, 0), "__\n__")], None, cx);
 621    });
 622    assert_new_snapshot(
 623        &multibuffer,
 624        &mut snapshot,
 625        &mut subscription,
 626        cx,
 627        indoc! {
 628            "
 629              one
 630              two
 631            + __
 632            + __THREE
 633              four
 634              five
 635            - six
 636              seven
 637            "
 638        },
 639    );
 640
 641    // Delete the newline before a deleted hunk.
 642    multibuffer.update(cx, |multibuffer, cx| {
 643        multibuffer.edit([(Point::new(5, 4)..Point::new(6, 0), "")], None, cx);
 644    });
 645    assert_new_snapshot(
 646        &multibuffer,
 647        &mut snapshot,
 648        &mut subscription,
 649        cx,
 650        indoc! {
 651            "
 652              one
 653              two
 654            + __
 655            + __THREE
 656              four
 657              fiveseven
 658            "
 659        },
 660    );
 661
 662    multibuffer.update(cx, |multibuffer, cx| multibuffer.undo(cx));
 663    assert_new_snapshot(
 664        &multibuffer,
 665        &mut snapshot,
 666        &mut subscription,
 667        cx,
 668        indoc! {
 669            "
 670              one
 671              two
 672            + __
 673            + __THREE
 674              four
 675              five
 676            - six
 677              seven
 678            "
 679        },
 680    );
 681
 682    // Cannot (yet) insert at the beginning of a deleted hunk.
 683    // (because it would put the newline in the wrong place)
 684    multibuffer.update(cx, |multibuffer, cx| {
 685        multibuffer.edit([(Point::new(6, 0)..Point::new(6, 0), "\n")], None, cx);
 686    });
 687    assert_new_snapshot(
 688        &multibuffer,
 689        &mut snapshot,
 690        &mut subscription,
 691        cx,
 692        indoc! {
 693            "
 694              one
 695              two
 696            + __
 697            + __THREE
 698              four
 699              five
 700            - six
 701              seven
 702            "
 703        },
 704    );
 705
 706    // Replace a range that ends in a deleted hunk.
 707    multibuffer.update(cx, |multibuffer, cx| {
 708        multibuffer.edit([(Point::new(5, 2)..Point::new(6, 2), "fty-")], None, cx);
 709    });
 710    assert_new_snapshot(
 711        &multibuffer,
 712        &mut snapshot,
 713        &mut subscription,
 714        cx,
 715        indoc! {
 716            "
 717              one
 718              two
 719            + __
 720            + __THREE
 721              four
 722              fifty-seven
 723            "
 724        },
 725    );
 726}
 727
 728#[gpui::test]
 729fn test_excerpt_events(cx: &mut App) {
 730    let buffer_1 = cx.new(|cx| Buffer::local(sample_text(10, 3, 'a'), cx));
 731    let buffer_2 = cx.new(|cx| Buffer::local(sample_text(10, 3, 'm'), cx));
 732
 733    let leader_multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
 734    let follower_multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
 735    let follower_edit_event_count = Arc::new(RwLock::new(0));
 736
 737    follower_multibuffer.update(cx, |_, cx| {
 738        let follower_edit_event_count = follower_edit_event_count.clone();
 739        cx.subscribe(
 740            &leader_multibuffer,
 741            move |follower, _, event, cx| match event.clone() {
 742                Event::BufferUpdated {
 743                    buffer,
 744                    path_key,
 745                    ranges,
 746                } => {
 747                    let buffer_snapshot = buffer.read(cx).snapshot();
 748                    follower.set_merged_excerpt_ranges_for_path(
 749                        path_key,
 750                        buffer,
 751                        &buffer_snapshot,
 752                        ranges,
 753                        cx,
 754                    );
 755                }
 756                Event::BuffersRemoved {
 757                    removed_buffer_ids, ..
 758                } => {
 759                    for id in removed_buffer_ids {
 760                        follower.remove_excerpts_for_buffer(id, cx);
 761                    }
 762                }
 763                Event::Edited { .. } => {
 764                    *follower_edit_event_count.write() += 1;
 765                }
 766                _ => {}
 767            },
 768        )
 769        .detach();
 770    });
 771
 772    let buffer_1_snapshot = buffer_1.read(cx).snapshot();
 773    let buffer_2_snapshot = buffer_2.read(cx).snapshot();
 774    leader_multibuffer.update(cx, |leader, cx| {
 775        leader.set_excerpt_ranges_for_path(
 776            PathKey::sorted(0),
 777            buffer_1.clone(),
 778            &buffer_1_snapshot,
 779            vec![
 780                ExcerptRange::new((0..8).to_point(&buffer_1_snapshot)),
 781                ExcerptRange::new((22..26).to_point(&buffer_1_snapshot)),
 782            ],
 783            cx,
 784        );
 785        leader.set_excerpt_ranges_for_path(
 786            PathKey::sorted(1),
 787            buffer_2.clone(),
 788            &buffer_2_snapshot,
 789            vec![
 790                ExcerptRange::new((0..5).to_point(&buffer_2_snapshot)),
 791                ExcerptRange::new((20..25).to_point(&buffer_2_snapshot)),
 792            ],
 793            cx,
 794        );
 795    });
 796    assert_eq!(
 797        leader_multibuffer.read(cx).snapshot(cx).text(),
 798        follower_multibuffer.read(cx).snapshot(cx).text(),
 799    );
 800    assert_eq!(*follower_edit_event_count.read(), 2);
 801
 802    leader_multibuffer.update(cx, |leader, cx| {
 803        leader.set_excerpt_ranges_for_path(
 804            PathKey::sorted(0),
 805            buffer_1.clone(),
 806            &buffer_1_snapshot,
 807            vec![ExcerptRange::new((0..8).to_point(&buffer_1_snapshot))],
 808            cx,
 809        );
 810        leader.set_excerpt_ranges_for_path(
 811            PathKey::sorted(1),
 812            buffer_2,
 813            &buffer_2_snapshot,
 814            vec![ExcerptRange::new((0..5).to_point(&buffer_2_snapshot))],
 815            cx,
 816        );
 817    });
 818    assert_eq!(
 819        leader_multibuffer.read(cx).snapshot(cx).text(),
 820        follower_multibuffer.read(cx).snapshot(cx).text(),
 821    );
 822    assert_eq!(*follower_edit_event_count.read(), 4);
 823
 824    leader_multibuffer.update(cx, |leader, cx| {
 825        leader.clear(cx);
 826    });
 827    assert_eq!(
 828        leader_multibuffer.read(cx).snapshot(cx).text(),
 829        follower_multibuffer.read(cx).snapshot(cx).text(),
 830    );
 831    assert_eq!(*follower_edit_event_count.read(), 5);
 832}
 833
 834#[gpui::test]
 835fn test_expand_excerpts(cx: &mut App) {
 836    let buffer = cx.new(|cx| Buffer::local(sample_text(20, 3, 'a'), cx));
 837    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
 838
 839    multibuffer.update(cx, |multibuffer, cx| {
 840        multibuffer.set_excerpts_for_path(
 841            PathKey::for_buffer(&buffer, cx),
 842            buffer,
 843            vec![
 844                // Note that in this test, this first excerpt
 845                // does not contain a new line
 846                Point::new(3, 2)..Point::new(3, 3),
 847                Point::new(7, 1)..Point::new(7, 3),
 848                Point::new(15, 0)..Point::new(15, 0),
 849            ],
 850            1,
 851            cx,
 852        )
 853    });
 854
 855    let snapshot = multibuffer.read(cx).snapshot(cx);
 856
 857    assert_eq!(
 858        snapshot.text(),
 859        concat!(
 860            "ccc\n", //
 861            "ddd\n", //
 862            "eee",   //
 863            "\n",    // End of excerpt
 864            "ggg\n", //
 865            "hhh\n", //
 866            "iii",   //
 867            "\n",    // End of excerpt
 868            "ooo\n", //
 869            "ppp\n", //
 870            "qqq",   // End of excerpt
 871        )
 872    );
 873    drop(snapshot);
 874
 875    multibuffer.update(cx, |multibuffer, cx| {
 876        let line_zero = multibuffer.snapshot(cx).anchor_before(Point::new(0, 0));
 877
 878        multibuffer.expand_excerpts_with_paths(
 879            multibuffer
 880                .snapshot(cx)
 881                .excerpts()
 882                .map(|(_, info)| Anchor::in_buffer(info.path_key_index, info.range.context.end)),
 883            1,
 884            ExpandExcerptDirection::UpAndDown,
 885            cx,
 886        );
 887        let snapshot = multibuffer.snapshot(cx);
 888        let line_two = snapshot.anchor_before(Point::new(2, 0));
 889        assert_eq!(line_two.cmp(&line_zero, &snapshot), cmp::Ordering::Greater);
 890    });
 891
 892    let snapshot = multibuffer.read(cx).snapshot(cx);
 893
 894    assert_eq!(
 895        snapshot.text(),
 896        concat!(
 897            "bbb\n", //
 898            "ccc\n", //
 899            "ddd\n", //
 900            "eee\n", //
 901            "fff\n", //
 902            "ggg\n", //
 903            "hhh\n", //
 904            "iii\n", //
 905            "jjj\n", // End of excerpt
 906            "nnn\n", //
 907            "ooo\n", //
 908            "ppp\n", //
 909            "qqq\n", //
 910            "rrr",   // End of excerpt
 911        )
 912    );
 913}
 914
 915#[gpui::test(iterations = 100)]
 916async fn test_set_anchored_excerpts_for_path(cx: &mut TestAppContext) {
 917    let buffer_1 = cx.new(|cx| Buffer::local(sample_text(20, 3, 'a'), cx));
 918    let buffer_2 = cx.new(|cx| Buffer::local(sample_text(15, 4, 'a'), cx));
 919    let snapshot_1 = buffer_1.update(cx, |buffer, _| buffer.snapshot());
 920    let snapshot_2 = buffer_2.update(cx, |buffer, _| buffer.snapshot());
 921    let ranges_1 = vec![
 922        snapshot_1.anchor_before(Point::new(3, 2))..snapshot_1.anchor_before(Point::new(4, 2)),
 923        snapshot_1.anchor_before(Point::new(7, 1))..snapshot_1.anchor_before(Point::new(7, 3)),
 924        snapshot_1.anchor_before(Point::new(15, 0))..snapshot_1.anchor_before(Point::new(15, 0)),
 925    ];
 926    let ranges_2 = vec![
 927        snapshot_2.anchor_before(Point::new(2, 1))..snapshot_2.anchor_before(Point::new(3, 1)),
 928        snapshot_2.anchor_before(Point::new(10, 0))..snapshot_2.anchor_before(Point::new(10, 2)),
 929    ];
 930
 931    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
 932    let anchor_ranges_1 = multibuffer
 933        .update(cx, |multibuffer, cx| {
 934            multibuffer.set_anchored_excerpts_for_path(
 935                PathKey::for_buffer(&buffer_1, cx),
 936                buffer_1.clone(),
 937                ranges_1,
 938                2,
 939                cx,
 940            )
 941        })
 942        .await;
 943    let snapshot_1 = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
 944    assert_eq!(
 945        anchor_ranges_1
 946            .iter()
 947            .map(|range| range.to_point(&snapshot_1))
 948            .collect::<Vec<_>>(),
 949        vec![
 950            Point::new(2, 2)..Point::new(3, 2),
 951            Point::new(6, 1)..Point::new(6, 3),
 952            Point::new(11, 0)..Point::new(11, 0),
 953        ]
 954    );
 955    let anchor_ranges_2 = multibuffer
 956        .update(cx, |multibuffer, cx| {
 957            multibuffer.set_anchored_excerpts_for_path(
 958                PathKey::for_buffer(&buffer_2, cx),
 959                buffer_2.clone(),
 960                ranges_2,
 961                2,
 962                cx,
 963            )
 964        })
 965        .await;
 966    let snapshot_2 = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
 967    assert_eq!(
 968        anchor_ranges_2
 969            .iter()
 970            .map(|range| range.to_point(&snapshot_2))
 971            .collect::<Vec<_>>(),
 972        vec![
 973            Point::new(16, 1)..Point::new(17, 1),
 974            Point::new(22, 0)..Point::new(22, 2)
 975        ]
 976    );
 977
 978    let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
 979    assert_eq!(
 980        snapshot.text(),
 981        concat!(
 982            "bbb\n", // buffer_1
 983            "ccc\n", //
 984            "ddd\n", // <-- excerpt 1
 985            "eee\n", // <-- excerpt 1
 986            "fff\n", //
 987            "ggg\n", //
 988            "hhh\n", // <-- excerpt 2
 989            "iii\n", //
 990            "jjj\n", //
 991            //
 992            "nnn\n", //
 993            "ooo\n", //
 994            "ppp\n", // <-- excerpt 3
 995            "qqq\n", //
 996            "rrr\n", //
 997            //
 998            "aaaa\n", // buffer 2
 999            "bbbb\n", //
1000            "cccc\n", // <-- excerpt 4
1001            "dddd\n", // <-- excerpt 4
1002            "eeee\n", //
1003            "ffff\n", //
1004            //
1005            "iiii\n", //
1006            "jjjj\n", //
1007            "kkkk\n", // <-- excerpt 5
1008            "llll\n", //
1009            "mmmm",   //
1010        )
1011    );
1012}
1013
1014#[gpui::test]
1015fn test_empty_multibuffer(cx: &mut App) {
1016    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
1017
1018    let snapshot = multibuffer.read(cx).snapshot(cx);
1019    assert_eq!(snapshot.text(), "");
1020    assert_eq!(
1021        snapshot
1022            .row_infos(MultiBufferRow(0))
1023            .map(|info| info.buffer_row)
1024            .collect::<Vec<_>>(),
1025        &[Some(0)]
1026    );
1027    assert!(
1028        snapshot
1029            .row_infos(MultiBufferRow(1))
1030            .map(|info| info.buffer_row)
1031            .collect::<Vec<_>>()
1032            .is_empty(),
1033    );
1034}
1035
1036#[gpui::test]
1037async fn test_empty_diff_excerpt(cx: &mut TestAppContext) {
1038    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
1039    let buffer = cx.new(|cx| Buffer::local("", cx));
1040    let base_text = "a\nb\nc";
1041
1042    let diff = cx
1043        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
1044    multibuffer.update(cx, |multibuffer, cx| {
1045        multibuffer.set_excerpt_ranges_for_path(
1046            PathKey::sorted(0),
1047            buffer.clone(),
1048            &buffer.read(cx).snapshot(),
1049            vec![ExcerptRange::new(Point::zero()..Point::zero())],
1050            cx,
1051        );
1052        multibuffer.set_all_diff_hunks_expanded(cx);
1053        multibuffer.add_diff(diff.clone(), cx);
1054    });
1055    cx.run_until_parked();
1056
1057    let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
1058    assert_eq!(snapshot.text(), "a\nb\nc\n");
1059
1060    let hunk = snapshot
1061        .diff_hunks_in_range(Point::new(1, 1)..Point::new(1, 1))
1062        .next()
1063        .unwrap();
1064
1065    assert_eq!(hunk.diff_base_byte_range.start, BufferOffset(0));
1066
1067    let buf2 = cx.new(|cx| Buffer::local("X", cx));
1068    multibuffer.update(cx, |multibuffer, cx| {
1069        multibuffer.set_excerpts_for_path(
1070            PathKey::sorted(1),
1071            buf2,
1072            [Point::new(0, 0)..Point::new(0, 1)],
1073            0,
1074            cx,
1075        );
1076    });
1077
1078    buffer.update(cx, |buffer, cx| {
1079        buffer.edit([(0..0, "a\nb\nc")], None, cx);
1080        diff.update(cx, |diff, cx| {
1081            diff.recalculate_diff_sync(&buffer.text_snapshot(), cx);
1082        });
1083        assert_eq!(buffer.text(), "a\nb\nc")
1084    });
1085    cx.run_until_parked();
1086
1087    let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
1088    assert_eq!(snapshot.text(), "a\nb\nc\nX");
1089
1090    buffer.update(cx, |buffer, cx| {
1091        buffer.undo(cx);
1092        diff.update(cx, |diff, cx| {
1093            diff.recalculate_diff_sync(&buffer.text_snapshot(), cx);
1094        });
1095        assert_eq!(buffer.text(), "")
1096    });
1097    cx.run_until_parked();
1098
1099    let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
1100    assert_eq!(snapshot.text(), "a\nb\nc\n\nX");
1101}
1102
1103#[gpui::test]
1104fn test_singleton_multibuffer_anchors(cx: &mut App) {
1105    let buffer = cx.new(|cx| Buffer::local("abcd", cx));
1106    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
1107    let old_snapshot = multibuffer.read(cx).snapshot(cx);
1108    buffer.update(cx, |buffer, cx| {
1109        buffer.edit([(0..0, "X")], None, cx);
1110        buffer.edit([(5..5, "Y")], None, cx);
1111    });
1112    let new_snapshot = multibuffer.read(cx).snapshot(cx);
1113
1114    assert_eq!(old_snapshot.text(), "abcd");
1115    assert_eq!(new_snapshot.text(), "XabcdY");
1116
1117    assert_eq!(
1118        old_snapshot
1119            .anchor_before(MultiBufferOffset(0))
1120            .to_offset(&new_snapshot),
1121        MultiBufferOffset(0)
1122    );
1123    assert_eq!(
1124        old_snapshot
1125            .anchor_after(MultiBufferOffset(0))
1126            .to_offset(&new_snapshot),
1127        MultiBufferOffset(1)
1128    );
1129    assert_eq!(
1130        old_snapshot
1131            .anchor_before(MultiBufferOffset(4))
1132            .to_offset(&new_snapshot),
1133        MultiBufferOffset(5)
1134    );
1135    assert_eq!(
1136        old_snapshot
1137            .anchor_after(MultiBufferOffset(4))
1138            .to_offset(&new_snapshot),
1139        MultiBufferOffset(6)
1140    );
1141}
1142
1143#[gpui::test]
1144fn test_multibuffer_anchors(cx: &mut App) {
1145    let buffer_1 = cx.new(|cx| Buffer::local("abcd", cx));
1146    let buffer_2 = cx.new(|cx| Buffer::local("efghi", cx));
1147    let multibuffer = cx.new(|cx| {
1148        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
1149        multibuffer.set_excerpts_for_path(
1150            PathKey::sorted(0),
1151            buffer_1.clone(),
1152            [Point::new(0, 0)..Point::new(0, 4)],
1153            0,
1154            cx,
1155        );
1156        multibuffer.set_excerpts_for_path(
1157            PathKey::sorted(1),
1158            buffer_2.clone(),
1159            [Point::new(0, 0)..Point::new(0, 5)],
1160            0,
1161            cx,
1162        );
1163        multibuffer
1164    });
1165    let old_snapshot = multibuffer.read(cx).snapshot(cx);
1166
1167    assert_eq!(
1168        old_snapshot
1169            .anchor_before(MultiBufferOffset(0))
1170            .to_offset(&old_snapshot),
1171        MultiBufferOffset(0)
1172    );
1173    assert_eq!(
1174        old_snapshot
1175            .anchor_after(MultiBufferOffset(0))
1176            .to_offset(&old_snapshot),
1177        MultiBufferOffset(0)
1178    );
1179    assert_eq!(Anchor::min().to_offset(&old_snapshot), MultiBufferOffset(0));
1180    assert_eq!(Anchor::min().to_offset(&old_snapshot), MultiBufferOffset(0));
1181    assert_eq!(
1182        Anchor::max().to_offset(&old_snapshot),
1183        MultiBufferOffset(10)
1184    );
1185    assert_eq!(
1186        Anchor::max().to_offset(&old_snapshot),
1187        MultiBufferOffset(10)
1188    );
1189
1190    buffer_1.update(cx, |buffer, cx| {
1191        buffer.edit([(0..0, "W")], None, cx);
1192        buffer.edit([(5..5, "X")], None, cx);
1193    });
1194    buffer_2.update(cx, |buffer, cx| {
1195        buffer.edit([(0..0, "Y")], None, cx);
1196        buffer.edit([(6..6, "Z")], None, cx);
1197    });
1198    let new_snapshot = multibuffer.read(cx).snapshot(cx);
1199
1200    assert_eq!(old_snapshot.text(), "abcd\nefghi");
1201    assert_eq!(new_snapshot.text(), "WabcdX\nYefghiZ");
1202
1203    assert_eq!(
1204        old_snapshot
1205            .anchor_before(MultiBufferOffset(0))
1206            .to_offset(&new_snapshot),
1207        MultiBufferOffset(0)
1208    );
1209    assert_eq!(
1210        old_snapshot
1211            .anchor_after(MultiBufferOffset(0))
1212            .to_offset(&new_snapshot),
1213        MultiBufferOffset(1)
1214    );
1215    assert_eq!(
1216        old_snapshot
1217            .anchor_before(MultiBufferOffset(1))
1218            .to_offset(&new_snapshot),
1219        MultiBufferOffset(2)
1220    );
1221    assert_eq!(
1222        old_snapshot
1223            .anchor_after(MultiBufferOffset(1))
1224            .to_offset(&new_snapshot),
1225        MultiBufferOffset(2)
1226    );
1227    assert_eq!(
1228        old_snapshot
1229            .anchor_before(MultiBufferOffset(2))
1230            .to_offset(&new_snapshot),
1231        MultiBufferOffset(3)
1232    );
1233    assert_eq!(
1234        old_snapshot
1235            .anchor_after(MultiBufferOffset(2))
1236            .to_offset(&new_snapshot),
1237        MultiBufferOffset(3)
1238    );
1239    assert_eq!(
1240        old_snapshot
1241            .anchor_before(MultiBufferOffset(5))
1242            .to_offset(&new_snapshot),
1243        MultiBufferOffset(7)
1244    );
1245    assert_eq!(
1246        old_snapshot
1247            .anchor_after(MultiBufferOffset(5))
1248            .to_offset(&new_snapshot),
1249        MultiBufferOffset(8)
1250    );
1251    assert_eq!(
1252        old_snapshot
1253            .anchor_before(MultiBufferOffset(10))
1254            .to_offset(&new_snapshot),
1255        MultiBufferOffset(13)
1256    );
1257    assert_eq!(
1258        old_snapshot
1259            .anchor_after(MultiBufferOffset(10))
1260            .to_offset(&new_snapshot),
1261        MultiBufferOffset(14)
1262    );
1263}
1264
1265#[gpui::test]
1266async fn test_basic_diff_hunks(cx: &mut TestAppContext) {
1267    let text = indoc!(
1268        "
1269        ZERO
1270        one
1271        TWO
1272        three
1273        six
1274        "
1275    );
1276    let base_text = indoc!(
1277        "
1278        one
1279        two
1280        three
1281        four
1282        five
1283        six
1284        "
1285    );
1286
1287    let buffer = cx.new(|cx| Buffer::local(text, cx));
1288    let diff = cx
1289        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
1290    cx.run_until_parked();
1291
1292    let multibuffer = cx.new(|cx| {
1293        let mut multibuffer = MultiBuffer::singleton(buffer.clone(), cx);
1294        multibuffer.add_diff(diff.clone(), cx);
1295        multibuffer
1296    });
1297
1298    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
1299        (multibuffer.snapshot(cx), multibuffer.subscribe())
1300    });
1301    assert_eq!(
1302        snapshot.text(),
1303        indoc!(
1304            "
1305            ZERO
1306            one
1307            TWO
1308            three
1309            six
1310            "
1311        ),
1312    );
1313
1314    multibuffer.update(cx, |multibuffer, cx| {
1315        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
1316    });
1317
1318    assert_new_snapshot(
1319        &multibuffer,
1320        &mut snapshot,
1321        &mut subscription,
1322        cx,
1323        indoc!(
1324            "
1325            + ZERO
1326              one
1327            - two
1328            + TWO
1329              three
1330            - four
1331            - five
1332              six
1333            "
1334        ),
1335    );
1336
1337    assert_eq!(
1338        snapshot
1339            .row_infos(MultiBufferRow(0))
1340            .map(|info| (info.buffer_row, info.diff_status))
1341            .collect::<Vec<_>>(),
1342        vec![
1343            (Some(0), Some(DiffHunkStatus::added_none())),
1344            (Some(1), None),
1345            (Some(1), Some(DiffHunkStatus::deleted_none())),
1346            (Some(2), Some(DiffHunkStatus::added_none())),
1347            (Some(3), None),
1348            (Some(3), Some(DiffHunkStatus::deleted_none())),
1349            (Some(4), Some(DiffHunkStatus::deleted_none())),
1350            (Some(4), None),
1351            (Some(5), None)
1352        ]
1353    );
1354
1355    assert_chunks_in_ranges(&snapshot);
1356    assert_consistent_line_numbers(&snapshot);
1357    assert_position_translation(&snapshot);
1358    assert_line_indents(&snapshot);
1359
1360    multibuffer.update(cx, |multibuffer, cx| {
1361        multibuffer.collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], cx)
1362    });
1363    assert_new_snapshot(
1364        &multibuffer,
1365        &mut snapshot,
1366        &mut subscription,
1367        cx,
1368        indoc!(
1369            "
1370            ZERO
1371            one
1372            TWO
1373            three
1374            six
1375            "
1376        ),
1377    );
1378
1379    assert_chunks_in_ranges(&snapshot);
1380    assert_consistent_line_numbers(&snapshot);
1381    assert_position_translation(&snapshot);
1382    assert_line_indents(&snapshot);
1383
1384    // Expand the first diff hunk
1385    multibuffer.update(cx, |multibuffer, cx| {
1386        let position = multibuffer.read(cx).anchor_before(Point::new(2, 2));
1387        multibuffer.expand_diff_hunks(vec![position..position], cx)
1388    });
1389    assert_new_snapshot(
1390        &multibuffer,
1391        &mut snapshot,
1392        &mut subscription,
1393        cx,
1394        indoc!(
1395            "
1396              ZERO
1397              one
1398            - two
1399            + TWO
1400              three
1401              six
1402            "
1403        ),
1404    );
1405
1406    // Expand the second diff hunk
1407    multibuffer.update(cx, |multibuffer, cx| {
1408        let start = multibuffer.read(cx).anchor_before(Point::new(4, 0));
1409        let end = multibuffer.read(cx).anchor_before(Point::new(5, 0));
1410        multibuffer.expand_diff_hunks(vec![start..end], cx)
1411    });
1412    assert_new_snapshot(
1413        &multibuffer,
1414        &mut snapshot,
1415        &mut subscription,
1416        cx,
1417        indoc!(
1418            "
1419              ZERO
1420              one
1421            - two
1422            + TWO
1423              three
1424            - four
1425            - five
1426              six
1427            "
1428        ),
1429    );
1430
1431    assert_chunks_in_ranges(&snapshot);
1432    assert_consistent_line_numbers(&snapshot);
1433    assert_position_translation(&snapshot);
1434    assert_line_indents(&snapshot);
1435
1436    // Edit the buffer before the first hunk
1437    buffer.update(cx, |buffer, cx| {
1438        buffer.edit_via_marked_text(
1439            indoc!(
1440                "
1441                ZERO
1442                one« hundred
1443                  thousand»
1444                TWO
1445                three
1446                six
1447                "
1448            ),
1449            None,
1450            cx,
1451        );
1452    });
1453    assert_new_snapshot(
1454        &multibuffer,
1455        &mut snapshot,
1456        &mut subscription,
1457        cx,
1458        indoc!(
1459            "
1460              ZERO
1461              one hundred
1462                thousand
1463            - two
1464            + TWO
1465              three
1466            - four
1467            - five
1468              six
1469            "
1470        ),
1471    );
1472
1473    assert_chunks_in_ranges(&snapshot);
1474    assert_consistent_line_numbers(&snapshot);
1475    assert_position_translation(&snapshot);
1476    assert_line_indents(&snapshot);
1477
1478    // Recalculate the diff, changing the first diff hunk.
1479    diff.update(cx, |diff, cx| {
1480        diff.recalculate_diff_sync(&buffer.read(cx).text_snapshot(), cx);
1481    });
1482    cx.run_until_parked();
1483    assert_new_snapshot(
1484        &multibuffer,
1485        &mut snapshot,
1486        &mut subscription,
1487        cx,
1488        indoc!(
1489            "
1490              ZERO
1491              one hundred
1492                thousand
1493              TWO
1494              three
1495            - four
1496            - five
1497              six
1498            "
1499        ),
1500    );
1501
1502    assert_eq!(
1503        snapshot
1504            .diff_hunks_in_range(MultiBufferOffset(0)..snapshot.len())
1505            .map(|hunk| hunk.row_range.start.0..hunk.row_range.end.0)
1506            .collect::<Vec<_>>(),
1507        &[0..4, 5..7]
1508    );
1509}
1510
1511#[gpui::test]
1512async fn test_repeatedly_expand_a_diff_hunk(cx: &mut TestAppContext) {
1513    let text = indoc!(
1514        "
1515        one
1516        TWO
1517        THREE
1518        four
1519        FIVE
1520        six
1521        "
1522    );
1523    let base_text = indoc!(
1524        "
1525        one
1526        four
1527        five
1528        six
1529        "
1530    );
1531
1532    let buffer = cx.new(|cx| Buffer::local(text, cx));
1533    let diff = cx
1534        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
1535    cx.run_until_parked();
1536
1537    let multibuffer = cx.new(|cx| {
1538        let mut multibuffer = MultiBuffer::singleton(buffer.clone(), cx);
1539        multibuffer.add_diff(diff.clone(), cx);
1540        multibuffer
1541    });
1542
1543    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
1544        (multibuffer.snapshot(cx), multibuffer.subscribe())
1545    });
1546
1547    multibuffer.update(cx, |multibuffer, cx| {
1548        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
1549    });
1550
1551    assert_new_snapshot(
1552        &multibuffer,
1553        &mut snapshot,
1554        &mut subscription,
1555        cx,
1556        indoc!(
1557            "
1558              one
1559            + TWO
1560            + THREE
1561              four
1562            - five
1563            + FIVE
1564              six
1565            "
1566        ),
1567    );
1568
1569    // Regression test: expanding diff hunks that are already expanded should not change anything.
1570    multibuffer.update(cx, |multibuffer, cx| {
1571        multibuffer.expand_diff_hunks(
1572            vec![
1573                snapshot.anchor_before(Point::new(2, 0))..snapshot.anchor_before(Point::new(2, 0)),
1574            ],
1575            cx,
1576        );
1577    });
1578
1579    assert_new_snapshot(
1580        &multibuffer,
1581        &mut snapshot,
1582        &mut subscription,
1583        cx,
1584        indoc!(
1585            "
1586              one
1587            + TWO
1588            + THREE
1589              four
1590            - five
1591            + FIVE
1592              six
1593            "
1594        ),
1595    );
1596
1597    // Now collapse all diff hunks
1598    multibuffer.update(cx, |multibuffer, cx| {
1599        multibuffer.collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
1600    });
1601
1602    assert_new_snapshot(
1603        &multibuffer,
1604        &mut snapshot,
1605        &mut subscription,
1606        cx,
1607        indoc!(
1608            "
1609            one
1610            TWO
1611            THREE
1612            four
1613            FIVE
1614            six
1615            "
1616        ),
1617    );
1618
1619    // Expand the hunks again, but this time provide two ranges that are both within the same hunk
1620    // Target the first hunk which is between "one" and "four"
1621    multibuffer.update(cx, |multibuffer, cx| {
1622        multibuffer.expand_diff_hunks(
1623            vec![
1624                snapshot.anchor_before(Point::new(4, 0))..snapshot.anchor_before(Point::new(4, 0)),
1625                snapshot.anchor_before(Point::new(4, 2))..snapshot.anchor_before(Point::new(4, 2)),
1626            ],
1627            cx,
1628        );
1629    });
1630    assert_new_snapshot(
1631        &multibuffer,
1632        &mut snapshot,
1633        &mut subscription,
1634        cx,
1635        indoc!(
1636            "
1637              one
1638              TWO
1639              THREE
1640              four
1641            - five
1642            + FIVE
1643              six
1644            "
1645        ),
1646    );
1647}
1648
1649#[gpui::test]
1650fn test_set_excerpts_for_buffer_ordering(cx: &mut TestAppContext) {
1651    let buf1 = cx.new(|cx| {
1652        Buffer::local(
1653            indoc! {
1654            "zero
1655            one
1656            two
1657            two.five
1658            three
1659            four
1660            five
1661            six
1662            seven
1663            eight
1664            nine
1665            ten
1666            eleven
1667            ",
1668            },
1669            cx,
1670        )
1671    });
1672    let path1: PathKey = PathKey::with_sort_prefix(0, rel_path("root").into_arc());
1673
1674    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
1675    multibuffer.update(cx, |multibuffer, cx| {
1676        multibuffer.set_excerpts_for_path(
1677            path1.clone(),
1678            buf1.clone(),
1679            vec![
1680                Point::row_range(1..2),
1681                Point::row_range(6..7),
1682                Point::row_range(11..12),
1683            ],
1684            1,
1685            cx,
1686        );
1687    });
1688
1689    assert_excerpts_match(
1690        &multibuffer,
1691        cx,
1692        indoc! {
1693            "-----
1694            zero
1695            one
1696            two
1697            two.five
1698            -----
1699            four
1700            five
1701            six
1702            seven
1703            -----
1704            nine
1705            ten
1706            eleven
1707            "
1708        },
1709    );
1710
1711    buf1.update(cx, |buffer, cx| buffer.edit([(0..5, "")], None, cx));
1712
1713    multibuffer.update(cx, |multibuffer, cx| {
1714        multibuffer.set_excerpts_for_path(
1715            path1.clone(),
1716            buf1.clone(),
1717            vec![
1718                Point::row_range(0..3),
1719                Point::row_range(5..7),
1720                Point::row_range(10..11),
1721            ],
1722            1,
1723            cx,
1724        );
1725    });
1726
1727    assert_excerpts_match(
1728        &multibuffer,
1729        cx,
1730        indoc! {
1731            "-----
1732             one
1733             two
1734             two.five
1735             three
1736             four
1737             five
1738             six
1739             seven
1740             eight
1741             nine
1742             ten
1743             eleven
1744            "
1745        },
1746    );
1747}
1748
1749#[gpui::test]
1750fn test_set_excerpts_for_buffer(cx: &mut TestAppContext) {
1751    let buf1 = cx.new(|cx| {
1752        Buffer::local(
1753            indoc! {
1754            "zero
1755            one
1756            two
1757            three
1758            four
1759            five
1760            six
1761            seven
1762            ",
1763            },
1764            cx,
1765        )
1766    });
1767    let path1: PathKey = PathKey::with_sort_prefix(0, rel_path("root").into_arc());
1768    let buf2 = cx.new(|cx| {
1769        Buffer::local(
1770            indoc! {
1771            "000
1772            111
1773            222
1774            333
1775            444
1776            555
1777            666
1778            777
1779            888
1780            999
1781            "
1782            },
1783            cx,
1784        )
1785    });
1786    let path2 = PathKey::with_sort_prefix(1, rel_path("root").into_arc());
1787
1788    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
1789    multibuffer.update(cx, |multibuffer, cx| {
1790        multibuffer.set_excerpts_for_path(
1791            path1.clone(),
1792            buf1.clone(),
1793            vec![Point::row_range(0..1)],
1794            2,
1795            cx,
1796        );
1797    });
1798
1799    assert_excerpts_match(
1800        &multibuffer,
1801        cx,
1802        indoc! {
1803        "-----
1804        zero
1805        one
1806        two
1807        three
1808        "
1809        },
1810    );
1811
1812    multibuffer.update(cx, |multibuffer, cx| {
1813        multibuffer.set_excerpts_for_path(path1.clone(), buf1.clone(), vec![], 2, cx);
1814    });
1815
1816    assert_excerpts_match(&multibuffer, cx, "");
1817
1818    multibuffer.update(cx, |multibuffer, cx| {
1819        multibuffer.set_excerpts_for_path(
1820            path1.clone(),
1821            buf1.clone(),
1822            vec![Point::row_range(0..1), Point::row_range(7..8)],
1823            2,
1824            cx,
1825        );
1826    });
1827
1828    assert_excerpts_match(
1829        &multibuffer,
1830        cx,
1831        indoc! {"-----
1832                zero
1833                one
1834                two
1835                three
1836                -----
1837                five
1838                six
1839                seven
1840                "},
1841    );
1842
1843    multibuffer.update(cx, |multibuffer, cx| {
1844        multibuffer.set_excerpts_for_path(
1845            path1.clone(),
1846            buf1.clone(),
1847            vec![Point::row_range(0..1), Point::row_range(5..6)],
1848            2,
1849            cx,
1850        );
1851    });
1852
1853    assert_excerpts_match(
1854        &multibuffer,
1855        cx,
1856        indoc! {"-----
1857                    zero
1858                    one
1859                    two
1860                    three
1861                    four
1862                    five
1863                    six
1864                    seven
1865                    "},
1866    );
1867
1868    multibuffer.update(cx, |multibuffer, cx| {
1869        multibuffer.set_excerpts_for_path(
1870            path2.clone(),
1871            buf2.clone(),
1872            vec![Point::row_range(2..3)],
1873            2,
1874            cx,
1875        );
1876    });
1877
1878    assert_excerpts_match(
1879        &multibuffer,
1880        cx,
1881        indoc! {"-----
1882                zero
1883                one
1884                two
1885                three
1886                four
1887                five
1888                six
1889                seven
1890                -----
1891                000
1892                111
1893                222
1894                333
1895                444
1896                555
1897                "},
1898    );
1899
1900    multibuffer.update(cx, |multibuffer, cx| {
1901        multibuffer.set_excerpts_for_path(path1.clone(), buf1.clone(), vec![], 2, cx);
1902    });
1903
1904    multibuffer.update(cx, |multibuffer, cx| {
1905        multibuffer.set_excerpts_for_path(
1906            path1.clone(),
1907            buf1.clone(),
1908            vec![Point::row_range(3..4)],
1909            2,
1910            cx,
1911        );
1912    });
1913
1914    assert_excerpts_match(
1915        &multibuffer,
1916        cx,
1917        indoc! {"-----
1918                one
1919                two
1920                three
1921                four
1922                five
1923                six
1924                -----
1925                000
1926                111
1927                222
1928                333
1929                444
1930                555
1931                "},
1932    );
1933
1934    multibuffer.update(cx, |multibuffer, cx| {
1935        multibuffer.set_excerpts_for_path(
1936            path1.clone(),
1937            buf1.clone(),
1938            vec![Point::row_range(3..4)],
1939            2,
1940            cx,
1941        );
1942    });
1943}
1944
1945#[gpui::test]
1946fn test_set_excerpts_for_buffer_rename(cx: &mut TestAppContext) {
1947    let buf1 = cx.new(|cx| {
1948        Buffer::local(
1949            indoc! {
1950            "zero
1951            one
1952            two
1953            three
1954            four
1955            five
1956            six
1957            seven
1958            ",
1959            },
1960            cx,
1961        )
1962    });
1963    let path: PathKey = PathKey::with_sort_prefix(0, rel_path("root").into_arc());
1964    let buf2 = cx.new(|cx| {
1965        Buffer::local(
1966            indoc! {
1967            "000
1968            111
1969            222
1970            333
1971            "
1972            },
1973            cx,
1974        )
1975    });
1976
1977    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
1978    multibuffer.update(cx, |multibuffer, cx| {
1979        multibuffer.set_excerpts_for_path(
1980            path.clone(),
1981            buf1.clone(),
1982            vec![Point::row_range(1..1), Point::row_range(4..5)],
1983            1,
1984            cx,
1985        );
1986    });
1987
1988    assert_excerpts_match(
1989        &multibuffer,
1990        cx,
1991        indoc! {
1992        "-----
1993        zero
1994        one
1995        two
1996        three
1997        four
1998        five
1999        six
2000        "
2001        },
2002    );
2003
2004    multibuffer.update(cx, |multibuffer, cx| {
2005        multibuffer.set_excerpts_for_path(
2006            path.clone(),
2007            buf2.clone(),
2008            vec![Point::row_range(0..1)],
2009            2,
2010            cx,
2011        );
2012    });
2013
2014    assert_excerpts_match(
2015        &multibuffer,
2016        cx,
2017        indoc! {"-----
2018                000
2019                111
2020                222
2021                333
2022                "},
2023    );
2024}
2025
2026#[gpui::test]
2027async fn test_diff_hunks_with_multiple_excerpts(cx: &mut TestAppContext) {
2028    let base_text_1 = indoc!(
2029        "
2030        one
2031        two
2032            three
2033        four
2034        five
2035        six
2036        "
2037    );
2038    let text_1 = indoc!(
2039        "
2040        ZERO
2041        one
2042        TWO
2043            three
2044        six
2045        "
2046    );
2047    let base_text_2 = indoc!(
2048        "
2049        seven
2050          eight
2051        nine
2052        ten
2053        eleven
2054        twelve
2055        "
2056    );
2057    let text_2 = indoc!(
2058        "
2059          eight
2060        nine
2061        eleven
2062        THIRTEEN
2063        FOURTEEN
2064        "
2065    );
2066
2067    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
2068    let buffer_2 = cx.new(|cx| Buffer::local(text_2, cx));
2069    let diff_1 = cx.new(|cx| {
2070        BufferDiff::new_with_base_text(base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
2071    });
2072    let diff_2 = cx.new(|cx| {
2073        BufferDiff::new_with_base_text(base_text_2, &buffer_2.read(cx).text_snapshot(), cx)
2074    });
2075    cx.run_until_parked();
2076
2077    let multibuffer = cx.new(|cx| {
2078        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
2079        multibuffer.set_excerpts_for_path(
2080            PathKey::sorted(0),
2081            buffer_1.clone(),
2082            [Point::zero()..buffer_1.read(cx).max_point()],
2083            0,
2084            cx,
2085        );
2086        multibuffer.set_excerpts_for_path(
2087            PathKey::sorted(1),
2088            buffer_2.clone(),
2089            [Point::zero()..buffer_2.read(cx).max_point()],
2090            0,
2091            cx,
2092        );
2093        multibuffer.add_diff(diff_1.clone(), cx);
2094        multibuffer.add_diff(diff_2.clone(), cx);
2095        multibuffer
2096    });
2097
2098    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
2099        (multibuffer.snapshot(cx), multibuffer.subscribe())
2100    });
2101    assert_eq!(
2102        snapshot.text(),
2103        indoc!(
2104            "
2105            ZERO
2106            one
2107            TWO
2108                three
2109            six
2110
2111              eight
2112            nine
2113            eleven
2114            THIRTEEN
2115            FOURTEEN
2116            "
2117        ),
2118    );
2119
2120    multibuffer.update(cx, |multibuffer, cx| {
2121        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
2122    });
2123
2124    assert_new_snapshot(
2125        &multibuffer,
2126        &mut snapshot,
2127        &mut subscription,
2128        cx,
2129        indoc!(
2130            "
2131            + ZERO
2132              one
2133            - two
2134            + TWO
2135                  three
2136            - four
2137            - five
2138              six
2139
2140            - seven
2141                eight
2142              nine
2143            - ten
2144              eleven
2145            - twelve
2146            + THIRTEEN
2147            + FOURTEEN
2148            "
2149        ),
2150    );
2151
2152    let id_1 = buffer_1.read_with(cx, |buffer, _| buffer.remote_id());
2153    let id_2 = buffer_2.read_with(cx, |buffer, _| buffer.remote_id());
2154    let base_id_1 = diff_1.read_with(cx, |diff, cx| diff.base_text(cx).remote_id());
2155    let base_id_2 = diff_2.read_with(cx, |diff, cx| diff.base_text(cx).remote_id());
2156
2157    let buffer_lines = (0..=snapshot.max_row().0)
2158        .map(|row| {
2159            let (buffer, range) = snapshot.buffer_line_for_row(MultiBufferRow(row))?;
2160            Some((
2161                buffer.remote_id(),
2162                buffer.text_for_range(range).collect::<String>(),
2163            ))
2164        })
2165        .collect::<Vec<_>>();
2166    pretty_assertions::assert_eq!(
2167        buffer_lines,
2168        [
2169            Some((id_1, "ZERO".into())),
2170            Some((id_1, "one".into())),
2171            Some((base_id_1, "two".into())),
2172            Some((id_1, "TWO".into())),
2173            Some((id_1, "    three".into())),
2174            Some((base_id_1, "four".into())),
2175            Some((base_id_1, "five".into())),
2176            Some((id_1, "six".into())),
2177            Some((id_1, "".into())),
2178            Some((base_id_2, "seven".into())),
2179            Some((id_2, "  eight".into())),
2180            Some((id_2, "nine".into())),
2181            Some((base_id_2, "ten".into())),
2182            Some((id_2, "eleven".into())),
2183            Some((base_id_2, "twelve".into())),
2184            Some((id_2, "THIRTEEN".into())),
2185            Some((id_2, "FOURTEEN".into())),
2186            Some((id_2, "".into())),
2187        ]
2188    );
2189
2190    let buffer_ids_by_range = [
2191        (Point::new(0, 0)..Point::new(0, 0), &[id_1] as &[_]),
2192        (Point::new(0, 0)..Point::new(2, 0), &[id_1]),
2193        (Point::new(2, 0)..Point::new(2, 0), &[id_1]),
2194        (Point::new(3, 0)..Point::new(3, 0), &[id_1]),
2195        (Point::new(8, 0)..Point::new(9, 0), &[id_1]),
2196        (Point::new(8, 0)..Point::new(10, 0), &[id_1, id_2]),
2197        (Point::new(9, 0)..Point::new(9, 0), &[id_2]),
2198    ];
2199    for (range, buffer_ids) in buffer_ids_by_range {
2200        assert_eq!(
2201            snapshot
2202                .buffer_ids_for_range(range.clone())
2203                .collect::<Vec<_>>(),
2204            buffer_ids,
2205            "buffer_ids_for_range({range:?}"
2206        );
2207    }
2208
2209    assert_position_translation(&snapshot);
2210    assert_line_indents(&snapshot);
2211
2212    assert_eq!(
2213        snapshot
2214            .diff_hunks_in_range(MultiBufferOffset(0)..snapshot.len())
2215            .map(|hunk| hunk.row_range.start.0..hunk.row_range.end.0)
2216            .collect::<Vec<_>>(),
2217        &[0..1, 2..4, 5..7, 9..10, 12..13, 14..17]
2218    );
2219
2220    buffer_2.update(cx, |buffer, cx| {
2221        buffer.edit_via_marked_text(
2222            indoc!(
2223                "
2224                  eight
2225                «»eleven
2226                THIRTEEN
2227                FOURTEEN
2228                "
2229            ),
2230            None,
2231            cx,
2232        );
2233    });
2234
2235    assert_new_snapshot(
2236        &multibuffer,
2237        &mut snapshot,
2238        &mut subscription,
2239        cx,
2240        indoc!(
2241            "
2242            + ZERO
2243              one
2244            - two
2245            + TWO
2246                  three
2247            - four
2248            - five
2249              six
2250
2251            - seven
2252                eight
2253              eleven
2254            - twelve
2255            + THIRTEEN
2256            + FOURTEEN
2257            "
2258        ),
2259    );
2260
2261    assert_line_indents(&snapshot);
2262}
2263
2264/// A naive implementation of a multi-buffer that does not maintain
2265/// any derived state, used for comparison in a randomized test.
2266#[derive(Default)]
2267struct ReferenceMultibuffer {
2268    excerpts: Vec<ReferenceExcerpt>,
2269    diffs: HashMap<BufferId, Entity<BufferDiff>>,
2270    inverted_diffs: HashMap<BufferId, (Entity<BufferDiff>, Entity<language::Buffer>)>,
2271    // todo!() is this the right model?
2272    expanded_diff_hunks_by_buffer: HashMap<BufferId, Vec<text::Anchor>>,
2273}
2274
2275#[derive(Debug)]
2276struct ReferenceExcerpt {
2277    path_key: PathKey,
2278    path_key_index: PathKeyIndex,
2279    buffer: Entity<Buffer>,
2280    range: Range<text::Anchor>,
2281}
2282
2283#[derive(Debug)]
2284struct ReferenceRegion {
2285    buffer_id: Option<BufferId>,
2286    range: Range<usize>,
2287    buffer_range: Option<Range<Point>>,
2288    status: Option<DiffHunkStatus>,
2289    excerpt_info: Option<ExcerptInfo>,
2290}
2291
2292impl ReferenceExcerpt {
2293    fn info(&self, cx: &App) -> ExcerptInfo {
2294        ExcerptInfo {
2295            path_key_index: self.path_key_index,
2296            buffer_id: self.buffer.read(cx).remote_id(),
2297            range: self.range.clone(),
2298        }
2299    }
2300}
2301
2302impl ReferenceMultibuffer {
2303    fn expand_excerpts(&mut self, excerpts: &HashSet<ExcerptInfo>, line_count: u32, cx: &App) {
2304        if line_count == 0 {
2305            return;
2306        }
2307
2308        for info in excerpts {
2309            let excerpt = self
2310                .excerpts
2311                .iter_mut()
2312                .find(|e| &e.info(cx) == info)
2313                .unwrap();
2314            let snapshot = excerpt.buffer.read(cx).snapshot();
2315            let mut point_range = excerpt.range.to_point(&snapshot);
2316            point_range.start = Point::new(point_range.start.row.saturating_sub(line_count), 0);
2317            point_range.end =
2318                snapshot.clip_point(Point::new(point_range.end.row + line_count, 0), Bias::Left);
2319            point_range.end.column = snapshot.line_len(point_range.end.row);
2320            excerpt.range =
2321                snapshot.anchor_before(point_range.start)..snapshot.anchor_after(point_range.end);
2322        }
2323    }
2324
2325    fn remove_excerpt(&mut self, info: ExcerptInfo, cx: &App) {
2326        let ix = self
2327            .excerpts
2328            .iter()
2329            .position(|excerpt| excerpt.info(cx) == info)
2330            .unwrap();
2331        let excerpt = self.excerpts.remove(ix);
2332        let buffer = excerpt.buffer.read(cx);
2333        let buffer_id = buffer.remote_id();
2334        log::info!(
2335            "Removing excerpt {}: {:?}",
2336            ix,
2337            buffer
2338                .text_for_range(excerpt.range.to_offset(buffer))
2339                .collect::<String>(),
2340        );
2341        if !self
2342            .excerpts
2343            .iter()
2344            .any(|excerpt| excerpt.buffer.read(cx).remote_id() == buffer_id)
2345        {
2346            self.diffs.remove(&buffer_id);
2347            self.inverted_diffs.remove(&buffer_id);
2348        }
2349    }
2350
2351    fn set_excerpts(
2352        &mut self,
2353        path_key: PathKey,
2354        path_key_index: PathKeyIndex,
2355        buffer: Entity<Buffer>,
2356        ranges: Vec<Range<text::Anchor>>,
2357    ) {
2358        self.excerpts.retain(|excerpt| {
2359            excerpt.path_key != path_key && excerpt.buffer.entity_id() != buffer.entity_id()
2360        });
2361
2362        let (Ok(ix) | Err(ix)) = self
2363            .excerpts
2364            .binary_search_by(|probe| probe.path_key.cmp(&path_key));
2365        self.excerpts.splice(
2366            ix..ix,
2367            ranges.into_iter().map(|range| ReferenceExcerpt {
2368                path_key: path_key.clone(),
2369                path_key_index,
2370                buffer: buffer.clone(),
2371                range,
2372            }),
2373        );
2374    }
2375
2376    fn expand_diff_hunks(&mut self, path_key: PathKey, range: Range<text::Anchor>, cx: &App) {
2377        let excerpt = self
2378            .excerpts
2379            .iter_mut()
2380            .find(|e| {
2381                e.path_key == path_key
2382                    && e.range
2383                        .start
2384                        .cmp(&range.start, &e.buffer.read(cx).snapshot())
2385                        .is_le()
2386            })
2387            .unwrap();
2388        let buffer = excerpt.buffer.read(cx).snapshot();
2389        let buffer_id = buffer.remote_id();
2390
2391        // Skip inverted excerpts - hunks are always expanded
2392        if self.inverted_diffs.contains_key(&buffer_id) {
2393            return;
2394        }
2395
2396        let Some(diff) = self.diffs.get(&buffer_id) else {
2397            return;
2398        };
2399        let excerpt_range = excerpt.range.to_offset(&buffer);
2400        let expanded_diff_hunks = self
2401            .expanded_diff_hunks_by_buffer
2402            .entry(buffer_id)
2403            .or_default();
2404        for hunk in diff
2405            .read(cx)
2406            .snapshot(cx)
2407            .hunks_intersecting_range(range, &buffer)
2408        {
2409            let hunk_range = hunk.buffer_range.to_offset(&buffer);
2410            if hunk_range.start < excerpt_range.start || hunk_range.start > excerpt_range.end {
2411                continue;
2412            }
2413            if let Err(ix) = expanded_diff_hunks
2414                .binary_search_by(|anchor| anchor.cmp(&hunk.buffer_range.start, &buffer))
2415            {
2416                log::info!(
2417                    "expanding diff hunk {:?}. excerpt range:{:?}",
2418                    hunk_range,
2419                    excerpt_range
2420                );
2421                expanded_diff_hunks.insert(ix, hunk.buffer_range.start);
2422            } else {
2423                log::trace!("hunk {hunk_range:?} already expanded in excerpt");
2424            }
2425        }
2426    }
2427
2428    fn expected_content(&self, cx: &App) -> (String, Vec<RowInfo>, HashSet<MultiBufferRow>) {
2429        let mut text = String::new();
2430        let mut regions = Vec::<ReferenceRegion>::new();
2431        let mut excerpt_boundary_rows = HashSet::default();
2432        for excerpt in &self.excerpts {
2433            excerpt_boundary_rows.insert(MultiBufferRow(text.matches('\n').count() as u32));
2434            let buffer = excerpt.buffer.read(cx);
2435            let buffer_id = buffer.remote_id();
2436            let buffer_range = excerpt.range.to_offset(buffer);
2437
2438            if let Some((diff, main_buffer)) = self.inverted_diffs.get(&buffer_id) {
2439                let diff_snapshot = diff.read(cx).snapshot(cx);
2440                let main_buffer_snapshot = main_buffer.read(cx).snapshot();
2441
2442                let mut offset = buffer_range.start;
2443                for hunk in diff_snapshot.hunks_intersecting_base_text_range(
2444                    buffer_range.clone(),
2445                    &main_buffer_snapshot.text,
2446                ) {
2447                    let mut hunk_base_range = hunk.diff_base_byte_range.clone();
2448
2449                    hunk_base_range.end = hunk_base_range.end.min(buffer_range.end);
2450                    if hunk_base_range.start > buffer_range.end
2451                        || hunk_base_range.start < buffer_range.start
2452                    {
2453                        continue;
2454                    }
2455
2456                    // Add the text before the hunk
2457                    if hunk_base_range.start >= offset {
2458                        let len = text.len();
2459                        text.extend(buffer.text_for_range(offset..hunk_base_range.start));
2460                        if text.len() > len {
2461                            regions.push(ReferenceRegion {
2462                                buffer_id: Some(buffer_id),
2463                                range: len..text.len(),
2464                                buffer_range: Some(
2465                                    (offset..hunk_base_range.start).to_point(&buffer),
2466                                ),
2467                                status: None,
2468                                excerpt_info: Some(excerpt.info(cx)),
2469                            });
2470                        }
2471                    }
2472
2473                    // Add the "deleted" region (base text that's not in main)
2474                    if !hunk_base_range.is_empty() {
2475                        let len = text.len();
2476                        text.extend(buffer.text_for_range(hunk_base_range.clone()));
2477                        regions.push(ReferenceRegion {
2478                            buffer_id: Some(buffer_id),
2479                            range: len..text.len(),
2480                            buffer_range: Some(hunk_base_range.to_point(&buffer)),
2481                            status: Some(DiffHunkStatus::deleted(hunk.secondary_status)),
2482                            excerpt_info: Some(excerpt.info(cx)),
2483                        });
2484                    }
2485
2486                    offset = hunk_base_range.end;
2487                }
2488
2489                // Add remaining buffer text
2490                let len = text.len();
2491                text.extend(buffer.text_for_range(offset..buffer_range.end));
2492                text.push('\n');
2493                regions.push(ReferenceRegion {
2494                    buffer_id: Some(buffer_id),
2495                    range: len..text.len(),
2496                    buffer_range: Some((offset..buffer_range.end).to_point(&buffer)),
2497                    status: None,
2498                    excerpt_info: Some(excerpt.info(cx)),
2499                });
2500            } else {
2501                let diff = self.diffs.get(&buffer_id).unwrap().read(cx).snapshot(cx);
2502                let base_buffer = diff.base_text();
2503
2504                let mut offset = buffer_range.start;
2505                let hunks = diff
2506                    .hunks_intersecting_range(excerpt.range.clone(), buffer)
2507                    .peekable();
2508
2509                for hunk in hunks {
2510                    // Ignore hunks that are outside the excerpt range.
2511                    let mut hunk_range = hunk.buffer_range.to_offset(buffer);
2512
2513                    hunk_range.end = hunk_range.end.min(buffer_range.end);
2514                    if hunk_range.start > buffer_range.end || hunk_range.start < buffer_range.start
2515                    {
2516                        log::trace!("skipping hunk outside excerpt range");
2517                        continue;
2518                    }
2519
2520                    if !self
2521                        .expanded_diff_hunks_by_buffer
2522                        .get(&buffer_id)
2523                        .cloned()
2524                        .into_iter()
2525                        .flatten()
2526                        .any(|expanded_anchor| {
2527                            expanded_anchor.to_offset(buffer).max(buffer_range.start)
2528                                == hunk_range.start.max(buffer_range.start)
2529                        })
2530                    {
2531                        log::trace!("skipping a hunk that's not marked as expanded");
2532                        continue;
2533                    }
2534
2535                    if !hunk.buffer_range.start.is_valid(buffer) {
2536                        log::trace!("skipping hunk with deleted start: {:?}", hunk.range);
2537                        continue;
2538                    }
2539
2540                    if hunk_range.start >= offset {
2541                        // Add the buffer text before the hunk
2542                        let len = text.len();
2543                        text.extend(buffer.text_for_range(offset..hunk_range.start));
2544                        if text.len() > len {
2545                            regions.push(ReferenceRegion {
2546                                buffer_id: Some(buffer_id),
2547                                range: len..text.len(),
2548                                buffer_range: Some((offset..hunk_range.start).to_point(&buffer)),
2549                                status: None,
2550                                excerpt_info: Some(excerpt.info(cx)),
2551                            });
2552                        }
2553
2554                        // Add the deleted text for the hunk.
2555                        if !hunk.diff_base_byte_range.is_empty() {
2556                            let mut base_text = base_buffer
2557                                .text_for_range(hunk.diff_base_byte_range.clone())
2558                                .collect::<String>();
2559                            if !base_text.ends_with('\n') {
2560                                base_text.push('\n');
2561                            }
2562                            let len = text.len();
2563                            text.push_str(&base_text);
2564                            regions.push(ReferenceRegion {
2565                                buffer_id: Some(base_buffer.remote_id()),
2566                                range: len..text.len(),
2567                                buffer_range: Some(
2568                                    hunk.diff_base_byte_range.to_point(&base_buffer),
2569                                ),
2570                                status: Some(DiffHunkStatus::deleted(hunk.secondary_status)),
2571                                excerpt_info: Some(excerpt.info(cx)),
2572                            });
2573                        }
2574
2575                        offset = hunk_range.start;
2576                    }
2577
2578                    // Add the inserted text for the hunk.
2579                    if hunk_range.end > offset {
2580                        let len = text.len();
2581                        text.extend(buffer.text_for_range(offset..hunk_range.end));
2582                        let range = len..text.len();
2583                        let region = ReferenceRegion {
2584                            buffer_id: Some(buffer_id),
2585                            range,
2586                            buffer_range: Some((offset..hunk_range.end).to_point(&buffer)),
2587                            status: Some(DiffHunkStatus::added(hunk.secondary_status)),
2588                            excerpt_info: Some(excerpt.info(cx)),
2589                        };
2590                        offset = hunk_range.end;
2591                        regions.push(region);
2592                    }
2593                }
2594
2595                // Add the buffer text for the rest of the excerpt.
2596                let len = text.len();
2597                text.extend(buffer.text_for_range(offset..buffer_range.end));
2598                text.push('\n');
2599                regions.push(ReferenceRegion {
2600                    buffer_id: Some(buffer_id),
2601                    range: len..text.len(),
2602                    buffer_range: Some((offset..buffer_range.end).to_point(&buffer)),
2603                    status: None,
2604                    excerpt_info: Some(excerpt.info(cx)),
2605                });
2606            }
2607        }
2608
2609        // Remove final trailing newline.
2610        if self.excerpts.is_empty() {
2611            regions.push(ReferenceRegion {
2612                buffer_id: None,
2613                range: 0..1,
2614                buffer_range: Some(Point::new(0, 0)..Point::new(0, 1)),
2615                status: None,
2616                excerpt_info: None,
2617            });
2618        } else {
2619            text.pop();
2620        }
2621
2622        // Retrieve the row info using the region that contains
2623        // the start of each multi-buffer line.
2624        let mut ix = 0;
2625        let row_infos = text
2626            .split('\n')
2627            .map(|line| {
2628                let row_info = regions
2629                    .iter()
2630                    .position(|region| region.range.contains(&ix))
2631                    .map_or(RowInfo::default(), |region_ix| {
2632                        let region = &regions[region_ix];
2633                        let buffer_row = region.buffer_range.as_ref().map(|buffer_range| {
2634                            buffer_range.start.row
2635                                + text[region.range.start..ix].matches('\n').count() as u32
2636                        });
2637                        let main_buffer = self
2638                            .excerpts
2639                            .iter()
2640                            .find(|e| e.info(cx) == region.excerpt_info.unwrap())
2641                            .map(|e| e.buffer.clone());
2642                        let is_excerpt_start = region_ix == 0
2643                            || &regions[region_ix - 1].excerpt_info != &region.excerpt_info
2644                            || regions[region_ix - 1].range.is_empty();
2645                        let mut is_excerpt_end = region_ix == regions.len() - 1
2646                            || &regions[region_ix + 1].excerpt_info != &region.excerpt_info;
2647                        let is_start = !text[region.range.start..ix].contains('\n');
2648                        let mut is_end = if region.range.end > text.len() {
2649                            !text[ix..].contains('\n')
2650                        } else {
2651                            text[ix..region.range.end.min(text.len())]
2652                                .matches('\n')
2653                                .count()
2654                                == 1
2655                        };
2656                        if region_ix < regions.len() - 1
2657                            && !text[ix..].contains("\n")
2658                            && (region.status == Some(DiffHunkStatus::added_none())
2659                                || region.status.is_some_and(|s| s.is_deleted()))
2660                            && regions[region_ix + 1].excerpt_info == region.excerpt_info
2661                            && regions[region_ix + 1].range.start == text.len()
2662                        {
2663                            is_end = true;
2664                            is_excerpt_end = true;
2665                        }
2666                        let multibuffer_row =
2667                            MultiBufferRow(text[..ix].matches('\n').count() as u32);
2668                        let mut expand_direction = None;
2669                        if let Some(buffer) = &main_buffer {
2670                            let buffer_row = buffer_row.unwrap();
2671                            let needs_expand_up = is_excerpt_start && is_start && buffer_row > 0;
2672                            let needs_expand_down = is_excerpt_end
2673                                && is_end
2674                                && buffer.read(cx).max_point().row > buffer_row;
2675                            expand_direction = if needs_expand_up && needs_expand_down {
2676                                Some(ExpandExcerptDirection::UpAndDown)
2677                            } else if needs_expand_up {
2678                                Some(ExpandExcerptDirection::Up)
2679                            } else if needs_expand_down {
2680                                Some(ExpandExcerptDirection::Down)
2681                            } else {
2682                                None
2683                            };
2684                        }
2685                        RowInfo {
2686                            buffer_id: region.buffer_id,
2687                            diff_status: region.status,
2688                            buffer_row,
2689                            wrapped_buffer_row: None,
2690
2691                            multibuffer_row: Some(multibuffer_row),
2692                            expand_info: expand_direction.zip(region.excerpt_info.clone()).map(
2693                                |(direction, excerpt_info)| ExpandInfo {
2694                                    direction,
2695                                    excerpt_range: excerpt_info.range.context,
2696                                },
2697                            ),
2698                        }
2699                    });
2700                ix += line.len() + 1;
2701                row_info
2702            })
2703            .collect();
2704
2705        (text, row_infos, excerpt_boundary_rows)
2706    }
2707
2708    fn diffs_updated(&mut self, cx: &App) {
2709        for excerpt in &mut self.excerpts {
2710            let buffer = excerpt.buffer.read(cx).snapshot();
2711            let buffer_id = buffer.remote_id();
2712
2713            // Skip inverted diff excerpts - hunks are always expanded
2714            if self.inverted_diffs.contains_key(&buffer_id) {
2715                continue;
2716            }
2717
2718            let excerpt_range = excerpt.range.to_offset(&buffer);
2719            let Some(diff) = self.diffs.get(&buffer_id) else {
2720                continue;
2721            };
2722            let diff = diff.read(cx).snapshot(cx);
2723            let mut hunks = diff.hunks_in_row_range(0..u32::MAX, &buffer).peekable();
2724            self.expanded_diff_hunks_by_buffer
2725                .entry(buffer_id)
2726                .or_default()
2727                .retain(|hunk_anchor| {
2728                    if !hunk_anchor.is_valid(&buffer) {
2729                        return false;
2730                    }
2731                    while let Some(hunk) = hunks.peek() {
2732                        match hunk.buffer_range.start.cmp(hunk_anchor, &buffer) {
2733                            cmp::Ordering::Less => {
2734                                hunks.next();
2735                            }
2736                            cmp::Ordering::Equal => {
2737                                let hunk_range = hunk.buffer_range.to_offset(&buffer);
2738                                return hunk_range.end >= excerpt_range.start
2739                                    && hunk_range.start <= excerpt_range.end;
2740                            }
2741                            cmp::Ordering::Greater => break,
2742                        }
2743                    }
2744                    false
2745                });
2746        }
2747    }
2748
2749    fn add_diff(&mut self, diff: Entity<BufferDiff>, cx: &mut App) {
2750        let buffer_id = diff.read(cx).buffer_id;
2751        self.diffs.insert(buffer_id, diff);
2752    }
2753
2754    fn add_inverted_diff(
2755        &mut self,
2756        diff: Entity<BufferDiff>,
2757        main_buffer: Entity<language::Buffer>,
2758        cx: &App,
2759    ) {
2760        let base_text_buffer_id = diff.read(cx).base_text(cx).remote_id();
2761        self.inverted_diffs
2762            .insert(base_text_buffer_id, (diff, main_buffer));
2763    }
2764}
2765
2766#[gpui::test(iterations = 100)]
2767async fn test_random_set_ranges(cx: &mut TestAppContext, mut rng: StdRng) {
2768    let base_text = "a\n".repeat(100);
2769    let buf = cx.update(|cx| cx.new(|cx| Buffer::local(base_text, cx)));
2770    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
2771
2772    let operations = env::var("OPERATIONS")
2773        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2774        .unwrap_or(10);
2775
2776    fn row_ranges(ranges: &Vec<Range<Point>>) -> Vec<Range<u32>> {
2777        ranges
2778            .iter()
2779            .map(|range| range.start.row..range.end.row)
2780            .collect()
2781    }
2782
2783    for _ in 0..operations {
2784        let snapshot = buf.update(cx, |buf, _| buf.snapshot());
2785        let num_ranges = rng.random_range(0..=10);
2786        let max_row = snapshot.max_point().row;
2787        let mut ranges = (0..num_ranges)
2788            .map(|_| {
2789                let start = rng.random_range(0..max_row);
2790                let end = rng.random_range(start + 1..max_row + 1);
2791                Point::row_range(start..end)
2792            })
2793            .collect::<Vec<_>>();
2794        ranges.sort_by_key(|range| range.start);
2795        log::info!("Setting ranges: {:?}", row_ranges(&ranges));
2796        let (created, _) = multibuffer.update(cx, |multibuffer, cx| {
2797            multibuffer.set_excerpts_for_path(
2798                PathKey::for_buffer(&buf, cx),
2799                buf.clone(),
2800                ranges.clone(),
2801                2,
2802                cx,
2803            )
2804        });
2805
2806        assert_eq!(created.len(), ranges.len());
2807
2808        let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2809        let mut last_end = None;
2810        let mut seen_ranges = Vec::default();
2811
2812        for (_, buf, range) in snapshot.excerpts() {
2813            let start = range.context.start.to_point(buf);
2814            let end = range.context.end.to_point(buf);
2815            seen_ranges.push(start..end);
2816
2817            if let Some(last_end) = last_end.take() {
2818                assert!(
2819                    start > last_end,
2820                    "multibuffer has out-of-order ranges: {:?}; {:?} <= {:?}",
2821                    row_ranges(&seen_ranges),
2822                    start,
2823                    last_end
2824                )
2825            }
2826
2827            ranges.retain(|range| range.start < start || range.end > end);
2828
2829            last_end = Some(end)
2830        }
2831
2832        assert!(
2833            ranges.is_empty(),
2834            "multibuffer {:?} did not include all ranges: {:?}",
2835            row_ranges(&seen_ranges),
2836            row_ranges(&ranges)
2837        );
2838    }
2839}
2840
2841#[gpui::test(iterations = 100)]
2842async fn test_random_multibuffer(cx: &mut TestAppContext, mut rng: StdRng) {
2843    let operations = env::var("OPERATIONS")
2844        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2845        .unwrap_or(10);
2846    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
2847    let mut buffers: Vec<Entity<Buffer>> = Vec::new();
2848    let mut base_texts: HashMap<BufferId, String> = HashMap::default();
2849    let mut reference = ReferenceMultibuffer::default();
2850    let mut anchors = Vec::new();
2851    let mut old_versions = Vec::new();
2852    let mut needs_diff_calculation = false;
2853    let mut inverted_diff_main_buffers: HashMap<BufferId, Entity<BufferDiff>> = HashMap::default();
2854    for _ in 0..operations {
2855        match rng.random_range(0..100) {
2856            0..=14 if !buffers.is_empty() => {
2857                let buffer = buffers.choose(&mut rng).unwrap();
2858                buffer.update(cx, |buf, cx| {
2859                    let edit_count = rng.random_range(1..5);
2860                    buf.randomly_edit(&mut rng, edit_count, cx);
2861                    log::info!("buffer text:\n{}", buf.text());
2862                    needs_diff_calculation = true;
2863                });
2864                cx.update(|cx| reference.diffs_updated(cx));
2865            }
2866            15..=19 if !reference.excerpts.is_empty() => {
2867                multibuffer.update(cx, |multibuffer, cx| {
2868                    let snapshot = multibuffer.snapshot(cx);
2869                    let infos = snapshot
2870                        .excerpts()
2871                        .map(|(_, info)| info)
2872                        .collect::<Vec<_>>();
2873                    let mut excerpts = HashSet::default();
2874                    for _ in 0..rng.random_range(0..infos.len()) {
2875                        excerpts.extend(infos.choose(&mut rng).cloned());
2876                    }
2877
2878                    let line_count = rng.random_range(0..5);
2879
2880                    let excerpt_ixs = excerpts
2881                        .iter()
2882                        .map(|info| {
2883                            reference
2884                                .excerpts
2885                                .iter()
2886                                .position(|e| e.info(cx) == *info)
2887                                .unwrap()
2888                        })
2889                        .collect::<Vec<_>>();
2890                    log::info!("Expanding excerpts {excerpt_ixs:?} by {line_count} lines");
2891                    multibuffer.expand_excerpts_with_paths(
2892                        excerpts.iter().map(|info| {
2893                            Anchor::in_buffer(info.path_key_index, info.range.context.end)
2894                        }),
2895                        line_count,
2896                        ExpandExcerptDirection::UpAndDown,
2897                        cx,
2898                    );
2899
2900                    reference.expand_excerpts(&excerpts, line_count, cx);
2901                });
2902            }
2903            20..=29 if !reference.excerpts.is_empty() => {
2904                let mut excerpts_to_remove = vec![];
2905                for _ in 0..rng.random_range(1..=3) {
2906                    let Some(excerpt) = reference.excerpts.choose(&mut rng) else {
2907                        break;
2908                    };
2909                    let info = cx.update(|cx| excerpt.info(cx));
2910                    cx.update(|cx| reference.remove_excerpt(info, cx));
2911                    excerpts_to_remove.push(info);
2912                }
2913                let snapshot =
2914                    multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2915                excerpts_to_remove.sort_unstable_by(|a, b| {
2916                    let a_anchor = Anchor::in_buffer(a.path_key_index, a.range.context.start);
2917                    let b_anchor = Anchor::in_buffer(b.path_key_index, b.range.context.start);
2918                    a_anchor.cmp(&b_anchor, &snapshot)
2919                });
2920                drop(snapshot);
2921                multibuffer.update(cx, |multibuffer, cx| {
2922                    multibuffer.remove_excerpts(excerpts_to_remove, cx)
2923                });
2924            }
2925            30..=39 if !reference.excerpts.is_empty() => {
2926                let multibuffer =
2927                    multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2928                let offset = multibuffer.clip_offset(
2929                    MultiBufferOffset(rng.random_range(0..=multibuffer.len().0)),
2930                    Bias::Left,
2931                );
2932                let bias = if rng.random() {
2933                    Bias::Left
2934                } else {
2935                    Bias::Right
2936                };
2937                log::info!("Creating anchor at {} with bias {:?}", offset.0, bias);
2938                anchors.push(multibuffer.anchor_at(offset, bias));
2939                anchors.sort_by(|a, b| a.cmp(b, &multibuffer));
2940            }
2941            40..=44 => todo!("refresh anchors was here"),
2942            45..=55 if !reference.excerpts.is_empty() => {
2943                multibuffer.update(cx, |multibuffer, cx| {
2944                    let snapshot = multibuffer.snapshot(cx);
2945                    let excerpt_ix = rng.random_range(0..reference.excerpts.len());
2946                    let excerpt = &reference.excerpts[excerpt_ix];
2947
2948                    // Skip inverted excerpts - hunks can't be collapsed
2949                    let buffer_id = excerpt.buffer.read(cx).remote_id();
2950                    if reference.inverted_diffs.contains_key(&buffer_id) {
2951                        return;
2952                    }
2953
2954                    let start = excerpt.range.start;
2955                    let end = excerpt.range.end;
2956                    let range = snapshot.anchor_in_buffer(excerpt.info(cx).buffer_id, start).unwrap()
2957                        ..snapshot.anchor_in_buffer(excerpt.info(cx).buffer_id, end).unwrap();
2958
2959                    log::info!(
2960                        "expanding diff hunks in range {:?} (excerpt index {excerpt_ix:?}, buffer id {:?})",
2961                        range.to_offset(&snapshot),
2962                        buffer_id,
2963                    );
2964                    reference.expand_diff_hunks(excerpt.path_key.clone(), start..end, cx);
2965                    multibuffer.expand_diff_hunks(vec![range], cx);
2966                });
2967            }
2968            56..=85 if needs_diff_calculation => {
2969                multibuffer.update(cx, |multibuffer, cx| {
2970                    for buffer in multibuffer.all_buffers() {
2971                        let snapshot = buffer.read(cx).snapshot();
2972                        let buffer_id = snapshot.remote_id();
2973
2974                        if let Some(diff) = multibuffer.diff_for(buffer_id) {
2975                            diff.update(cx, |diff, cx| {
2976                                log::info!("recalculating diff for buffer {:?}", buffer_id,);
2977                                diff.recalculate_diff_sync(&snapshot.text, cx);
2978                            });
2979                        }
2980
2981                        if let Some(inverted_diff) = inverted_diff_main_buffers.get(&buffer_id) {
2982                            inverted_diff.update(cx, |diff, cx| {
2983                                log::info!(
2984                                    "recalculating inverted diff for main buffer {:?}",
2985                                    buffer_id,
2986                                );
2987                                diff.recalculate_diff_sync(&snapshot.text, cx);
2988                            });
2989                        }
2990                    }
2991                    reference.diffs_updated(cx);
2992                    needs_diff_calculation = false;
2993                });
2994            }
2995            _ => {
2996                // Decide if we're creating a new buffer or reusing an existing one
2997                let create_new_buffer = buffers.is_empty() || rng.random_bool(0.4);
2998
2999                let (excerpt_buffer, diff, inverted_main_buffer) = if create_new_buffer {
3000                    let create_inverted = rng.random_bool(0.3);
3001
3002                    if create_inverted {
3003                        let mut main_buffer_text = util::RandomCharIter::new(&mut rng)
3004                            .take(256)
3005                            .collect::<String>();
3006                        let main_buffer = cx.new(|cx| Buffer::local(main_buffer_text.clone(), cx));
3007                        text::LineEnding::normalize(&mut main_buffer_text);
3008                        let main_buffer_id =
3009                            main_buffer.read_with(cx, |buffer, _| buffer.remote_id());
3010                        base_texts.insert(main_buffer_id, main_buffer_text.clone());
3011                        buffers.push(main_buffer.clone());
3012
3013                        let diff = cx.new(|cx| {
3014                            BufferDiff::new_with_base_text(
3015                                &main_buffer_text,
3016                                &main_buffer.read(cx).text_snapshot(),
3017                                cx,
3018                            )
3019                        });
3020
3021                        let base_text_buffer =
3022                            diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3023
3024                        // Track for recalculation when main buffer is edited
3025                        inverted_diff_main_buffers.insert(main_buffer_id, diff.clone());
3026
3027                        (base_text_buffer, diff, Some(main_buffer))
3028                    } else {
3029                        let mut base_text = util::RandomCharIter::new(&mut rng)
3030                            .take(256)
3031                            .collect::<String>();
3032
3033                        let buffer_handle = cx.new(|cx| Buffer::local(base_text.clone(), cx));
3034                        text::LineEnding::normalize(&mut base_text);
3035                        let buffer_id = buffer_handle.read_with(cx, |buffer, _| buffer.remote_id());
3036                        base_texts.insert(buffer_id, base_text.clone());
3037                        buffers.push(buffer_handle.clone());
3038
3039                        let diff = cx.new(|cx| {
3040                            BufferDiff::new_with_base_text(
3041                                &base_text,
3042                                &buffer_handle.read(cx).text_snapshot(),
3043                                cx,
3044                            )
3045                        });
3046
3047                        (buffer_handle, diff, None)
3048                    }
3049                } else {
3050                    // Reuse an existing buffer
3051                    let buffer_handle = buffers.choose(&mut rng).unwrap().clone();
3052                    let buffer_id = buffer_handle.read_with(cx, |buffer, _| buffer.remote_id());
3053
3054                    if let Some(diff) = inverted_diff_main_buffers.get(&buffer_id) {
3055                        let base_text_buffer =
3056                            diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3057                        (base_text_buffer, diff.clone(), Some(buffer_handle))
3058                    } else {
3059                        // Get existing diff or create new one for regular buffer
3060                        let diff = multibuffer
3061                            .read_with(cx, |mb, _| mb.diff_for(buffer_id))
3062                            .unwrap_or_else(|| {
3063                                let base_text = base_texts.get(&buffer_id).unwrap();
3064                                cx.new(|cx| {
3065                                    BufferDiff::new_with_base_text(
3066                                        base_text,
3067                                        &buffer_handle.read(cx).text_snapshot(),
3068                                        cx,
3069                                    )
3070                                })
3071                            });
3072                        (buffer_handle, diff, None)
3073                    }
3074                };
3075
3076                let mut ranges = reference
3077                    .excerpts
3078                    .iter()
3079                    .map(|excerpt| excerpt.range.clone());
3080                excerpt_buffer.read_with(cx, |buffer, cx| {
3081                    mutate_excerpt_ranges(&mut rng, &mut ranges, &buffer.snapshot(), 1);
3082                });
3083
3084                let ranges = ranges
3085                    .into_iter()
3086                    .map(ExcerptRange::new)
3087                    .collect::<Vec<_>>();
3088
3089                let (_, path_key_index, _) = multibuffer.update(cx, |multibuffer, cx| {
3090                    let excerpt_buffer_snapshot = excerpt_buffer.read(cx).snapshot();
3091                    multibuffer.set_excerpt_ranges_for_path(
3092                        path,
3093                        excerpt_buffer,
3094                        &excerpt_buffer_snapshot,
3095                        ranges,
3096                        cx,
3097                    )
3098                });
3099
3100                let path_key_index =
3101                    reference.set_excerpts(path, path_key_index, excerpt_buffer, ranges);
3102
3103                let excerpt_buffer_id =
3104                    excerpt_buffer.read_with(cx, |buffer, _| buffer.remote_id());
3105                multibuffer.update(cx, |multibuffer, cx| {
3106                    if multibuffer.diff_for(excerpt_buffer_id).is_none() {
3107                        if let Some(main_buffer) = inverted_main_buffer {
3108                            reference.add_inverted_diff(diff.clone(), main_buffer.clone(), cx);
3109                            multibuffer.add_inverted_diff(diff, main_buffer, cx);
3110                        } else {
3111                            reference.add_diff(diff.clone(), cx);
3112                            multibuffer.add_diff(diff, cx);
3113                        }
3114                    }
3115                });
3116            }
3117        }
3118
3119        if rng.random_bool(0.3) {
3120            multibuffer.update(cx, |multibuffer, cx| {
3121                old_versions.push((multibuffer.snapshot(cx), multibuffer.subscribe()));
3122            })
3123        }
3124
3125        multibuffer.read_with(cx, |multibuffer, cx| {
3126            check_multibuffer(multibuffer, &reference, &anchors, cx, &mut rng);
3127        });
3128    }
3129    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
3130    for (old_snapshot, subscription) in old_versions {
3131        check_multibuffer_edits(&snapshot, &old_snapshot, subscription);
3132    }
3133}
3134
3135fn mutate_excerpt_ranges(
3136    rng: &mut StdRng,
3137    existing_ranges: &mut Vec<Range<text::Anchor>>,
3138    buffer: &BufferSnapshot,
3139    operations: u32,
3140) {
3141    let mut indices_to_remove = HashSet::default();
3142    let mut ranges_to_add = Vec::new();
3143
3144    for _ in 0..operations {
3145        match rng.random_range(0..5) {
3146            0..=1 if !existing_ranges.is_empty() => {
3147                log::info!(
3148                    "Removing excerpt at {} of {} for buffer {}: {:?}[{:?}] = {:?}",
3149                    excerpt_ix,
3150                    reference.excerpts.len(),
3151                    buffer.remote_id(),
3152                    buffer.text(),
3153                    start_ix..end_ix,
3154                    &buffer.text()[start_ix..end_ix]
3155                );
3156                let index = existing_ranges.choose(rng).unwrap();
3157                existing_ranges.remove(index);
3158            }
3159            _ => {
3160                log::info!(
3161                    "Inserting excerpt at {} of {} for buffer {}: {:?}[{:?}] = {:?}",
3162                    excerpt_ix,
3163                    reference.excerpts.len(),
3164                    buffer.remote_id(),
3165                    buffer.text(),
3166                    start_ix..end_ix,
3167                    &buffer.text()[start_ix..end_ix]
3168                );
3169                let end_row = rng.random_range(0..=buffer.max_point().row);
3170                let start_row = rng.random_range(0..=end_row);
3171                let end_ix = buffer.point_to_offset(Point::new(end_row, 0));
3172                let start_ix = buffer.point_to_offset(Point::new(start_row, 0));
3173                let anchor_range = buffer.anchor_before(start_ix)..buffer.anchor_after(end_ix);
3174                ranges_to_add.push(anchor_range);
3175            }
3176        }
3177    }
3178
3179    existing_ranges.extend(ranges_to_add);
3180    existing_ranges.sort_by(|l, r| l.start.cmp(&r.start, buffer));
3181}
3182
3183fn check_multibuffer(
3184    multibuffer: &MultiBuffer,
3185    reference: &ReferenceMultibuffer,
3186    anchors: &[Anchor],
3187    cx: &App,
3188    rng: &mut StdRng,
3189) {
3190    let snapshot = multibuffer.snapshot(cx);
3191    let actual_text = snapshot.text();
3192    let actual_boundary_rows = snapshot
3193        .excerpt_boundaries_in_range(MultiBufferOffset(0)..)
3194        .map(|b| b.row)
3195        .collect::<HashSet<_>>();
3196    let actual_row_infos = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
3197
3198    let (expected_text, expected_row_infos, expected_boundary_rows) =
3199        reference.expected_content(cx);
3200
3201    let has_diff = actual_row_infos
3202        .iter()
3203        .any(|info| info.diff_status.is_some())
3204        || expected_row_infos
3205            .iter()
3206            .any(|info| info.diff_status.is_some());
3207    let actual_diff = format_diff(
3208        &actual_text,
3209        &actual_row_infos,
3210        &actual_boundary_rows,
3211        Some(has_diff),
3212    );
3213    let expected_diff = format_diff(
3214        &expected_text,
3215        &expected_row_infos,
3216        &expected_boundary_rows,
3217        Some(has_diff),
3218    );
3219
3220    log::info!("Multibuffer content:\n{}", actual_diff);
3221
3222    assert_eq!(
3223        actual_row_infos.len(),
3224        actual_text.split('\n').count(),
3225        "line count: {}",
3226        actual_text.split('\n').count()
3227    );
3228    pretty_assertions::assert_eq!(actual_diff, expected_diff);
3229    pretty_assertions::assert_eq!(actual_text, expected_text);
3230    pretty_assertions::assert_eq!(actual_row_infos, expected_row_infos);
3231
3232    for _ in 0..5 {
3233        let start_row = rng.random_range(0..=expected_row_infos.len());
3234        assert_eq!(
3235            snapshot
3236                .row_infos(MultiBufferRow(start_row as u32))
3237                .collect::<Vec<_>>(),
3238            &expected_row_infos[start_row..],
3239            "buffer_rows({})",
3240            start_row
3241        );
3242    }
3243
3244    assert_eq!(
3245        snapshot.widest_line_number(),
3246        expected_row_infos
3247            .into_iter()
3248            .filter_map(|info| {
3249                // For inverted diffs, deleted rows are visible and should be counted.
3250                // Only filter out deleted rows that are NOT from inverted diffs.
3251                let is_inverted_diff = info
3252                    .buffer_id
3253                    .is_some_and(|id| reference.inverted_diffs.contains_key(&id));
3254                if info.diff_status.is_some_and(|status| status.is_deleted()) && !is_inverted_diff {
3255                    None
3256                } else {
3257                    info.buffer_row
3258                }
3259            })
3260            .max()
3261            .unwrap()
3262            + 1
3263    );
3264    let reference_ranges = reference
3265        .excerpts
3266        .iter()
3267        .map(|excerpt| {
3268            (
3269                excerpt.id,
3270                excerpt.range.to_offset(&excerpt.buffer.read(cx).snapshot()),
3271            )
3272        })
3273        .collect::<HashMap<_, _>>();
3274    for i in 0..snapshot.len().0 {
3275        let excerpt = snapshot
3276            .excerpt_containing(MultiBufferOffset(i)..MultiBufferOffset(i))
3277            .unwrap();
3278        assert_eq!(
3279            excerpt.buffer_range().start.0..excerpt.buffer_range().end.0,
3280            reference_ranges[&excerpt.id()]
3281        );
3282    }
3283
3284    assert_consistent_line_numbers(&snapshot);
3285    assert_position_translation(&snapshot);
3286
3287    for (row, line) in expected_text.split('\n').enumerate() {
3288        assert_eq!(
3289            snapshot.line_len(MultiBufferRow(row as u32)),
3290            line.len() as u32,
3291            "line_len({}).",
3292            row
3293        );
3294    }
3295
3296    let text_rope = Rope::from(expected_text.as_str());
3297    for _ in 0..10 {
3298        let end_ix = text_rope.clip_offset(rng.random_range(0..=text_rope.len()), Bias::Right);
3299        let start_ix = text_rope.clip_offset(rng.random_range(0..=end_ix), Bias::Left);
3300
3301        let text_for_range = snapshot
3302            .text_for_range(MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix))
3303            .collect::<String>();
3304        assert_eq!(
3305            text_for_range,
3306            &expected_text[start_ix..end_ix],
3307            "incorrect text for range {:?}",
3308            start_ix..end_ix
3309        );
3310
3311        let expected_summary =
3312            MBTextSummary::from(TextSummary::from(&expected_text[start_ix..end_ix]));
3313        assert_eq!(
3314            snapshot.text_summary_for_range::<MBTextSummary, _>(
3315                MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix)
3316            ),
3317            expected_summary,
3318            "incorrect summary for range {:?}",
3319            start_ix..end_ix
3320        );
3321    }
3322
3323    // Anchor resolution
3324    let summaries = snapshot.summaries_for_anchors::<MultiBufferOffset, _>(anchors);
3325    assert_eq!(anchors.len(), summaries.len());
3326    for (anchor, resolved_offset) in anchors.iter().zip(summaries) {
3327        assert!(resolved_offset <= snapshot.len());
3328        assert_eq!(
3329            snapshot.summary_for_anchor::<MultiBufferOffset>(anchor),
3330            resolved_offset,
3331            "anchor: {:?}",
3332            anchor
3333        );
3334    }
3335
3336    for _ in 0..10 {
3337        let end_ix = text_rope.clip_offset(rng.random_range(0..=text_rope.len()), Bias::Right);
3338        assert_eq!(
3339            snapshot
3340                .reversed_chars_at(MultiBufferOffset(end_ix))
3341                .collect::<String>(),
3342            expected_text[..end_ix].chars().rev().collect::<String>(),
3343        );
3344    }
3345
3346    for _ in 0..10 {
3347        let end_ix = rng.random_range(0..=text_rope.len());
3348        let end_ix = text_rope.floor_char_boundary(end_ix);
3349        let start_ix = rng.random_range(0..=end_ix);
3350        let start_ix = text_rope.floor_char_boundary(start_ix);
3351        assert_eq!(
3352            snapshot
3353                .bytes_in_range(MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix))
3354                .flatten()
3355                .copied()
3356                .collect::<Vec<_>>(),
3357            expected_text.as_bytes()[start_ix..end_ix].to_vec(),
3358            "bytes_in_range({:?})",
3359            start_ix..end_ix,
3360        );
3361    }
3362}
3363
3364fn check_multibuffer_edits(
3365    snapshot: &MultiBufferSnapshot,
3366    old_snapshot: &MultiBufferSnapshot,
3367    subscription: Subscription<MultiBufferOffset>,
3368) {
3369    let edits = subscription.consume().into_inner();
3370
3371    log::info!(
3372        "applying subscription edits to old text: {:?}: {:#?}",
3373        old_snapshot.text(),
3374        edits,
3375    );
3376
3377    let mut text = old_snapshot.text();
3378    for edit in edits {
3379        let new_text: String = snapshot
3380            .text_for_range(edit.new.start..edit.new.end)
3381            .collect();
3382        text.replace_range(
3383            (edit.new.start.0..edit.new.start.0 + (edit.old.end.0 - edit.old.start.0)).clone(),
3384            &new_text,
3385        );
3386        pretty_assertions::assert_eq!(
3387            &text[0..edit.new.end.0],
3388            snapshot
3389                .text_for_range(MultiBufferOffset(0)..edit.new.end)
3390                .collect::<String>()
3391        );
3392    }
3393    pretty_assertions::assert_eq!(text, snapshot.text());
3394}
3395
3396#[gpui::test]
3397fn test_history(cx: &mut App) {
3398    let test_settings = SettingsStore::test(cx);
3399    cx.set_global(test_settings);
3400
3401    let group_interval: Duration = Duration::from_millis(1);
3402    let buffer_1 = cx.new(|cx| {
3403        let mut buf = Buffer::local("1234", cx);
3404        buf.set_group_interval(group_interval);
3405        buf
3406    });
3407    let buffer_2 = cx.new(|cx| {
3408        let mut buf = Buffer::local("5678", cx);
3409        buf.set_group_interval(group_interval);
3410        buf
3411    });
3412    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
3413    multibuffer.update(cx, |this, _| {
3414        this.set_group_interval(group_interval);
3415    });
3416    multibuffer.update(cx, |multibuffer, cx| {
3417        multibuffer.set_excerpts_for_path(
3418            PathKey::sorted(0),
3419            buffer_1.clone(),
3420            [Point::zero()..buffer_1.read(cx).max_point()],
3421            0,
3422            cx,
3423        );
3424        multibuffer.set_excerpts_for_path(
3425            PathKey::sorted(1),
3426            buffer_2.clone(),
3427            [Point::zero()..buffer_2.read(cx).max_point()],
3428            0,
3429            cx,
3430        );
3431    });
3432
3433    let mut now = Instant::now();
3434
3435    multibuffer.update(cx, |multibuffer, cx| {
3436        let transaction_1 = multibuffer.start_transaction_at(now, cx).unwrap();
3437        multibuffer.edit(
3438            [
3439                (Point::new(0, 0)..Point::new(0, 0), "A"),
3440                (Point::new(1, 0)..Point::new(1, 0), "A"),
3441            ],
3442            None,
3443            cx,
3444        );
3445        multibuffer.edit(
3446            [
3447                (Point::new(0, 1)..Point::new(0, 1), "B"),
3448                (Point::new(1, 1)..Point::new(1, 1), "B"),
3449            ],
3450            None,
3451            cx,
3452        );
3453        multibuffer.end_transaction_at(now, cx);
3454        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3455
3456        // Verify edited ranges for transaction 1
3457        assert_eq!(
3458            multibuffer.edited_ranges_for_transaction(transaction_1, cx),
3459            &[
3460                MultiBufferOffset(0)..MultiBufferOffset(2),
3461                MultiBufferOffset(7)..MultiBufferOffset(9),
3462            ]
3463        );
3464
3465        // Edit buffer 1 through the multibuffer
3466        now += 2 * group_interval;
3467        multibuffer.start_transaction_at(now, cx);
3468        multibuffer.edit(
3469            [(MultiBufferOffset(2)..MultiBufferOffset(2), "C")],
3470            None,
3471            cx,
3472        );
3473        multibuffer.end_transaction_at(now, cx);
3474        assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3475
3476        // Edit buffer 1 independently
3477        buffer_1.update(cx, |buffer_1, cx| {
3478            buffer_1.start_transaction_at(now);
3479            buffer_1.edit([(3..3, "D")], None, cx);
3480            buffer_1.end_transaction_at(now, cx);
3481
3482            now += 2 * group_interval;
3483            buffer_1.start_transaction_at(now);
3484            buffer_1.edit([(4..4, "E")], None, cx);
3485            buffer_1.end_transaction_at(now, cx);
3486        });
3487        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\nAB5678");
3488
3489        // An undo in the multibuffer undoes the multibuffer transaction
3490        // and also any individual buffer edits that have occurred since
3491        // that transaction.
3492        multibuffer.undo(cx);
3493        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3494
3495        multibuffer.undo(cx);
3496        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3497
3498        multibuffer.redo(cx);
3499        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3500
3501        multibuffer.redo(cx);
3502        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\nAB5678");
3503
3504        // Undo buffer 2 independently.
3505        buffer_2.update(cx, |buffer_2, cx| buffer_2.undo(cx));
3506        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\n5678");
3507
3508        // An undo in the multibuffer undoes the components of the
3509        // the last multibuffer transaction that are not already undone.
3510        multibuffer.undo(cx);
3511        assert_eq!(multibuffer.read(cx).text(), "AB1234\n5678");
3512
3513        multibuffer.undo(cx);
3514        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3515
3516        multibuffer.redo(cx);
3517        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3518
3519        buffer_1.update(cx, |buffer_1, cx| buffer_1.redo(cx));
3520        assert_eq!(multibuffer.read(cx).text(), "ABCD1234\nAB5678");
3521
3522        // Redo stack gets cleared after an edit.
3523        now += 2 * group_interval;
3524        multibuffer.start_transaction_at(now, cx);
3525        multibuffer.edit(
3526            [(MultiBufferOffset(0)..MultiBufferOffset(0), "X")],
3527            None,
3528            cx,
3529        );
3530        multibuffer.end_transaction_at(now, cx);
3531        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3532        multibuffer.redo(cx);
3533        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3534        multibuffer.undo(cx);
3535        assert_eq!(multibuffer.read(cx).text(), "ABCD1234\nAB5678");
3536        multibuffer.undo(cx);
3537        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3538
3539        // Transactions can be grouped manually.
3540        multibuffer.redo(cx);
3541        multibuffer.redo(cx);
3542        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3543        multibuffer.group_until_transaction(transaction_1, cx);
3544        multibuffer.undo(cx);
3545        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3546        multibuffer.redo(cx);
3547        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3548    });
3549}
3550
3551#[gpui::test]
3552async fn test_enclosing_indent(cx: &mut TestAppContext) {
3553    async fn enclosing_indent(
3554        text: &str,
3555        buffer_row: u32,
3556        cx: &mut TestAppContext,
3557    ) -> Option<(Range<u32>, LineIndent)> {
3558        let buffer = cx.update(|cx| MultiBuffer::build_simple(text, cx));
3559        let snapshot = cx.read(|cx| buffer.read(cx).snapshot(cx));
3560        let (range, indent) = snapshot
3561            .enclosing_indent(MultiBufferRow(buffer_row))
3562            .await?;
3563        Some((range.start.0..range.end.0, indent))
3564    }
3565
3566    assert_eq!(
3567        enclosing_indent(
3568            indoc!(
3569                "
3570                fn b() {
3571                    if c {
3572                        let d = 2;
3573                    }
3574                }
3575                "
3576            ),
3577            1,
3578            cx,
3579        )
3580        .await,
3581        Some((
3582            1..2,
3583            LineIndent {
3584                tabs: 0,
3585                spaces: 4,
3586                line_blank: false,
3587            }
3588        ))
3589    );
3590
3591    assert_eq!(
3592        enclosing_indent(
3593            indoc!(
3594                "
3595                fn b() {
3596                    if c {
3597                        let d = 2;
3598                    }
3599                }
3600                "
3601            ),
3602            2,
3603            cx,
3604        )
3605        .await,
3606        Some((
3607            1..2,
3608            LineIndent {
3609                tabs: 0,
3610                spaces: 4,
3611                line_blank: false,
3612            }
3613        ))
3614    );
3615
3616    assert_eq!(
3617        enclosing_indent(
3618            indoc!(
3619                "
3620                fn b() {
3621                    if c {
3622                        let d = 2;
3623
3624                        let e = 5;
3625                    }
3626                }
3627                "
3628            ),
3629            3,
3630            cx,
3631        )
3632        .await,
3633        Some((
3634            1..4,
3635            LineIndent {
3636                tabs: 0,
3637                spaces: 4,
3638                line_blank: false,
3639            }
3640        ))
3641    );
3642}
3643
3644#[gpui::test]
3645async fn test_summaries_for_anchors(cx: &mut TestAppContext) {
3646    let base_text_1 = indoc!(
3647        "
3648        bar
3649        "
3650    );
3651    let text_1 = indoc!(
3652        "
3653        BAR
3654        "
3655    );
3656    let base_text_2 = indoc!(
3657        "
3658        foo
3659        "
3660    );
3661    let text_2 = indoc!(
3662        "
3663        FOO
3664        "
3665    );
3666
3667    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
3668    let buffer_2 = cx.new(|cx| Buffer::local(text_2, cx));
3669    let diff_1 = cx.new(|cx| {
3670        BufferDiff::new_with_base_text(base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
3671    });
3672    let diff_2 = cx.new(|cx| {
3673        BufferDiff::new_with_base_text(base_text_2, &buffer_2.read(cx).text_snapshot(), cx)
3674    });
3675    cx.run_until_parked();
3676
3677    let mut ids = vec![];
3678    let multibuffer = cx.new(|cx| {
3679        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3680        multibuffer.set_all_diff_hunks_expanded(cx);
3681        multibuffer.set_excerpts_for_path(
3682            PathKey::sorted(0),
3683            buffer_1.clone(),
3684            [Point::zero()..buffer_1.read(cx).max_point()],
3685            0,
3686            cx,
3687        );
3688        multibuffer.set_excerpts_for_path(
3689            PathKey::sorted(1),
3690            buffer_2.clone(),
3691            [Point::zero()..buffer_2.read(cx).max_point()],
3692            0,
3693            cx,
3694        );
3695        multibuffer.add_diff(diff_1.clone(), cx);
3696        multibuffer.add_diff(diff_2.clone(), cx);
3697        ids = multibuffer.excerpt_ids();
3698        multibuffer
3699    });
3700
3701    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3702        (multibuffer.snapshot(cx), multibuffer.subscribe())
3703    });
3704
3705    assert_new_snapshot(
3706        &multibuffer,
3707        &mut snapshot,
3708        &mut subscription,
3709        cx,
3710        indoc!(
3711            "
3712            - bar
3713            + BAR
3714
3715            - foo
3716            + FOO
3717            "
3718        ),
3719    );
3720
3721    let anchor_1 = Anchor::text(ids[0], text::Anchor::MIN);
3722    let point_1 = snapshot.summaries_for_anchors::<Point, _>([&anchor_1])[0];
3723    assert_eq!(point_1, Point::new(0, 0));
3724
3725    let anchor_2 = Anchor::text(ids[1], text::Anchor::MIN);
3726    let point_2 = snapshot.summaries_for_anchors::<Point, _>([&anchor_2])[0];
3727    assert_eq!(point_2, Point::new(3, 0));
3728}
3729
3730#[gpui::test]
3731async fn test_trailing_deletion_without_newline(cx: &mut TestAppContext) {
3732    let base_text_1 = "one\ntwo".to_owned();
3733    let text_1 = "one\n".to_owned();
3734
3735    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
3736    let diff_1 = cx.new(|cx| {
3737        BufferDiff::new_with_base_text(&base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
3738    });
3739    cx.run_until_parked();
3740
3741    let multibuffer = cx.new(|cx| {
3742        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3743        multibuffer.set_excerpts_for_path(
3744            PathKey::sorted(0),
3745            buffer_1.clone(),
3746            [Point::zero()..buffer_1.read(cx).max_point()],
3747            0,
3748            cx,
3749        );
3750        multibuffer.add_diff(diff_1.clone(), cx);
3751        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
3752        multibuffer
3753    });
3754
3755    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3756        (multibuffer.snapshot(cx), multibuffer.subscribe())
3757    });
3758
3759    assert_new_snapshot(
3760        &multibuffer,
3761        &mut snapshot,
3762        &mut subscription,
3763        cx,
3764        indoc!(
3765            "
3766              one
3767            - two
3768            "
3769        ),
3770    );
3771
3772    assert_eq!(snapshot.max_point(), Point::new(2, 0));
3773    assert_eq!(snapshot.len().0, 8);
3774
3775    assert_eq!(
3776        snapshot
3777            .dimensions_from_points::<Point>([Point::new(2, 0)])
3778            .collect::<Vec<_>>(),
3779        vec![Point::new(2, 0)]
3780    );
3781
3782    let (_, translated_offset) = snapshot.point_to_buffer_offset(Point::new(2, 0)).unwrap();
3783    assert_eq!(translated_offset.0, "one\n".len());
3784    let (_, translated_point, _) = snapshot.point_to_buffer_point(Point::new(2, 0)).unwrap();
3785    assert_eq!(translated_point, Point::new(1, 0));
3786
3787    // The same, for an excerpt that's not at the end of the multibuffer.
3788
3789    let text_2 = "foo\n".to_owned();
3790    let buffer_2 = cx.new(|cx| Buffer::local(&text_2, cx));
3791    multibuffer.update(cx, |multibuffer, cx| {
3792        multibuffer.set_excerpt_ranges_for_path(
3793            PathKey::sorted(1),
3794            buffer_2.clone(),
3795            &buffer_2.read(cx).snapshot(),
3796            vec![ExcerptRange::new(Point::new(0, 0)..Point::new(1, 0))],
3797            cx,
3798        );
3799    });
3800
3801    assert_new_snapshot(
3802        &multibuffer,
3803        &mut snapshot,
3804        &mut subscription,
3805        cx,
3806        indoc!(
3807            "
3808              one
3809            - two
3810
3811              foo
3812            "
3813        ),
3814    );
3815
3816    assert_eq!(
3817        snapshot
3818            .dimensions_from_points::<Point>([Point::new(2, 0)])
3819            .collect::<Vec<_>>(),
3820        vec![Point::new(2, 0)]
3821    );
3822
3823    let buffer_1_id = buffer_1.read_with(cx, |buffer_1, _| buffer_1.remote_id());
3824    let (buffer, translated_offset) = snapshot.point_to_buffer_offset(Point::new(2, 0)).unwrap();
3825    assert_eq!(buffer.remote_id(), buffer_1_id);
3826    assert_eq!(translated_offset.0, "one\n".len());
3827    let (buffer, translated_point, _) = snapshot.point_to_buffer_point(Point::new(2, 0)).unwrap();
3828    assert_eq!(buffer.remote_id(), buffer_1_id);
3829    assert_eq!(translated_point, Point::new(1, 0));
3830}
3831
3832fn format_diff(
3833    text: &str,
3834    row_infos: &Vec<RowInfo>,
3835    boundary_rows: &HashSet<MultiBufferRow>,
3836    has_diff: Option<bool>,
3837) -> String {
3838    let has_diff =
3839        has_diff.unwrap_or_else(|| row_infos.iter().any(|info| info.diff_status.is_some()));
3840    text.split('\n')
3841        .enumerate()
3842        .zip(row_infos)
3843        .map(|((ix, line), info)| {
3844            let marker = match info.diff_status.map(|status| status.kind) {
3845                Some(DiffHunkStatusKind::Added) => "+ ",
3846                Some(DiffHunkStatusKind::Deleted) => "- ",
3847                Some(DiffHunkStatusKind::Modified) => unreachable!(),
3848                None => {
3849                    if has_diff && !line.is_empty() {
3850                        "  "
3851                    } else {
3852                        ""
3853                    }
3854                }
3855            };
3856            let boundary_row = if boundary_rows.contains(&MultiBufferRow(ix as u32)) {
3857                if has_diff {
3858                    "  ----------\n"
3859                } else {
3860                    "---------\n"
3861                }
3862            } else {
3863                ""
3864            };
3865            let expand = info
3866                .expand_info
3867                .map(|expand_info| match expand_info.direction {
3868                    ExpandExcerptDirection::Up => " [↑]",
3869                    ExpandExcerptDirection::Down => " [↓]",
3870                    ExpandExcerptDirection::UpAndDown => " [↕]",
3871                })
3872                .unwrap_or_default();
3873
3874            format!("{boundary_row}{marker}{line}{expand}")
3875            // let mbr = info
3876            //     .multibuffer_row
3877            //     .map(|row| format!("{:0>3}", row.0))
3878            //     .unwrap_or_else(|| "???".to_string());
3879            // let byte_range = format!("{byte_range_start:0>3}..{byte_range_end:0>3}");
3880            // format!("{boundary_row}Row: {mbr}, Bytes: {byte_range} | {marker}{line}{expand}")
3881        })
3882        .collect::<Vec<_>>()
3883        .join("\n")
3884}
3885
3886// fn format_transforms(snapshot: &MultiBufferSnapshot) -> String {
3887//     snapshot
3888//         .diff_transforms
3889//         .iter()
3890//         .map(|transform| {
3891//             let (kind, summary) = match transform {
3892//                 DiffTransform::DeletedHunk { summary, .. } => ("   Deleted", (*summary).into()),
3893//                 DiffTransform::FilteredInsertedHunk { summary, .. } => ("  Filtered", *summary),
3894//                 DiffTransform::InsertedHunk { summary, .. } => ("  Inserted", *summary),
3895//                 DiffTransform::Unmodified { summary, .. } => ("Unmodified", *summary),
3896//             };
3897//             format!("{kind}(len: {}, lines: {:?})", summary.len, summary.lines)
3898//         })
3899//         .join("\n")
3900// }
3901
3902// fn format_excerpts(snapshot: &MultiBufferSnapshot) -> String {
3903//     snapshot
3904//         .excerpts
3905//         .iter()
3906//         .map(|excerpt| {
3907//             format!(
3908//                 "Excerpt(buffer_range = {:?}, lines = {:?}, has_trailing_newline = {:?})",
3909//                 excerpt.range.context.to_point(&excerpt.buffer),
3910//                 excerpt.text_summary.lines,
3911//                 excerpt.has_trailing_newline
3912//             )
3913//         })
3914//         .join("\n")
3915// }
3916
3917#[gpui::test]
3918async fn test_singleton_with_inverted_diff(cx: &mut TestAppContext) {
3919    let text = indoc!(
3920        "
3921        ZERO
3922        one
3923        TWO
3924        three
3925        six
3926        "
3927    );
3928    let base_text = indoc!(
3929        "
3930        one
3931        two
3932        three
3933        four
3934        five
3935        six
3936        "
3937    );
3938
3939    let buffer = cx.new(|cx| Buffer::local(text, cx));
3940    let diff = cx
3941        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
3942    cx.run_until_parked();
3943
3944    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3945
3946    let multibuffer = cx.new(|cx| {
3947        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
3948        multibuffer.set_all_diff_hunks_expanded(cx);
3949        multibuffer.add_inverted_diff(diff.clone(), buffer.clone(), cx);
3950        multibuffer
3951    });
3952
3953    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3954        (multibuffer.snapshot(cx), multibuffer.subscribe())
3955    });
3956
3957    assert_eq!(snapshot.text(), base_text);
3958    assert_new_snapshot(
3959        &multibuffer,
3960        &mut snapshot,
3961        &mut subscription,
3962        cx,
3963        indoc!(
3964            "
3965              one
3966            - two
3967              three
3968            - four
3969            - five
3970              six
3971            "
3972        ),
3973    );
3974
3975    buffer.update(cx, |buffer, cx| {
3976        buffer.edit_via_marked_text(
3977            indoc!(
3978                "
3979                ZERO
3980                one
3981                «<inserted>»W«O
3982                T»hree
3983                six
3984                "
3985            ),
3986            None,
3987            cx,
3988        );
3989    });
3990    cx.run_until_parked();
3991    let update = diff
3992        .update(cx, |diff, cx| {
3993            diff.update_diff(
3994                buffer.read(cx).text_snapshot(),
3995                Some(base_text.into()),
3996                None,
3997                None,
3998                cx,
3999            )
4000        })
4001        .await;
4002    diff.update(cx, |diff, cx| {
4003        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4004    })
4005    .await;
4006    cx.run_until_parked();
4007
4008    assert_new_snapshot(
4009        &multibuffer,
4010        &mut snapshot,
4011        &mut subscription,
4012        cx,
4013        indoc! {
4014            "
4015              one
4016            - two
4017            - three
4018            - four
4019            - five
4020              six
4021            "
4022        },
4023    );
4024
4025    buffer.update(cx, |buffer, cx| {
4026        buffer.set_text("ZERO\nONE\nTWO\n", cx);
4027    });
4028    cx.run_until_parked();
4029    let update = diff
4030        .update(cx, |diff, cx| {
4031            diff.update_diff(
4032                buffer.read(cx).text_snapshot(),
4033                Some(base_text.into()),
4034                None,
4035                None,
4036                cx,
4037            )
4038        })
4039        .await;
4040    diff.update(cx, |diff, cx| {
4041        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4042    })
4043    .await;
4044    cx.run_until_parked();
4045
4046    assert_new_snapshot(
4047        &multibuffer,
4048        &mut snapshot,
4049        &mut subscription,
4050        cx,
4051        indoc! {
4052            "
4053            - one
4054            - two
4055            - three
4056            - four
4057            - five
4058            - six
4059            "
4060        },
4061    );
4062
4063    diff.update(cx, |diff, cx| {
4064        diff.set_base_text(
4065            Some("new base\n".into()),
4066            None,
4067            buffer.read(cx).text_snapshot(),
4068            cx,
4069        )
4070    })
4071    .await
4072    .unwrap();
4073    cx.run_until_parked();
4074
4075    assert_new_snapshot(
4076        &multibuffer,
4077        &mut snapshot,
4078        &mut subscription,
4079        cx,
4080        indoc! {"
4081            - new base
4082        "},
4083    );
4084}
4085
4086#[gpui::test]
4087async fn test_inverted_diff_base_text_change(cx: &mut TestAppContext) {
4088    let base_text = "aaa\nbbb\nccc\n";
4089    let text = "ddd\n";
4090    let buffer = cx.new(|cx| Buffer::local(text, cx));
4091    let diff = cx
4092        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
4093    cx.run_until_parked();
4094
4095    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
4096
4097    let multibuffer = cx.new(|cx| {
4098        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
4099        multibuffer.set_all_diff_hunks_expanded(cx);
4100        multibuffer.add_inverted_diff(diff.clone(), buffer.clone(), cx);
4101        multibuffer
4102    });
4103
4104    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
4105        (multibuffer.snapshot(cx), multibuffer.subscribe())
4106    });
4107
4108    assert_eq!(snapshot.text(), base_text);
4109    assert_new_snapshot(
4110        &multibuffer,
4111        &mut snapshot,
4112        &mut subscription,
4113        cx,
4114        indoc!(
4115            "
4116            - aaa
4117            - bbb
4118            - ccc
4119            "
4120        ),
4121    );
4122
4123    let update = diff
4124        .update(cx, |diff, cx| {
4125            diff.update_diff(
4126                buffer.read(cx).text_snapshot(),
4127                Some("ddd\n".into()),
4128                Some(true),
4129                None,
4130                cx,
4131            )
4132        })
4133        .await;
4134    diff.update(cx, |diff, cx| {
4135        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4136    })
4137    .detach();
4138
4139    let _hunks: Vec<_> = multibuffer
4140        .read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx))
4141        .diff_hunks()
4142        .collect();
4143}
4144
4145#[gpui::test]
4146async fn test_inverted_diff_secondary_version_mismatch(cx: &mut TestAppContext) {
4147    let base_text = "one\ntwo\nthree\nfour\nfive\n";
4148    let index_text = "one\nTWO\nthree\nfour\nfive\n";
4149    let buffer_text = "one\nTWO\nthree\nFOUR\nfive\n";
4150
4151    let buffer = cx.new(|cx| Buffer::local(buffer_text, cx));
4152
4153    let unstaged_diff = cx
4154        .new(|cx| BufferDiff::new_with_base_text(index_text, &buffer.read(cx).text_snapshot(), cx));
4155    cx.run_until_parked();
4156
4157    let uncommitted_diff = cx.new(|cx| {
4158        let mut diff =
4159            BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx);
4160        diff.set_secondary_diff(unstaged_diff.clone());
4161        diff
4162    });
4163    cx.run_until_parked();
4164
4165    buffer.update(cx, |buffer, cx| {
4166        buffer.edit([(0..0, "ZERO\n")], None, cx);
4167    });
4168
4169    let update = unstaged_diff
4170        .update(cx, |diff, cx| {
4171            diff.update_diff(
4172                buffer.read(cx).text_snapshot(),
4173                Some(index_text.into()),
4174                None,
4175                None,
4176                cx,
4177            )
4178        })
4179        .await;
4180    unstaged_diff
4181        .update(cx, |diff, cx| {
4182            diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4183        })
4184        .await;
4185
4186    let base_text_buffer =
4187        uncommitted_diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
4188
4189    let multibuffer = cx.new(|cx| {
4190        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
4191        multibuffer.set_all_diff_hunks_expanded(cx);
4192        multibuffer.add_inverted_diff(uncommitted_diff.clone(), buffer.clone(), cx);
4193        multibuffer
4194    });
4195
4196    let _hunks: Vec<_> = multibuffer
4197        .read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx))
4198        .diff_hunks()
4199        .collect();
4200}
4201
4202#[track_caller]
4203fn assert_excerpts_match(
4204    multibuffer: &Entity<MultiBuffer>,
4205    cx: &mut TestAppContext,
4206    expected: &str,
4207) {
4208    let mut output = String::new();
4209    multibuffer.read_with(cx, |multibuffer, cx| {
4210        for (_, buffer, range) in multibuffer.snapshot(cx).excerpts() {
4211            output.push_str("-----\n");
4212            output.extend(buffer.text_for_range(range.context));
4213            if !output.ends_with('\n') {
4214                output.push('\n');
4215            }
4216        }
4217    });
4218    assert_eq!(output, expected);
4219}
4220
4221#[track_caller]
4222fn assert_new_snapshot(
4223    multibuffer: &Entity<MultiBuffer>,
4224    snapshot: &mut MultiBufferSnapshot,
4225    subscription: &mut Subscription<MultiBufferOffset>,
4226    cx: &mut TestAppContext,
4227    expected_diff: &str,
4228) {
4229    let new_snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
4230    let actual_text = new_snapshot.text();
4231    let line_infos = new_snapshot
4232        .row_infos(MultiBufferRow(0))
4233        .collect::<Vec<_>>();
4234    let actual_diff = format_diff(&actual_text, &line_infos, &Default::default(), None);
4235    pretty_assertions::assert_eq!(actual_diff, expected_diff);
4236    check_edits(
4237        snapshot,
4238        &new_snapshot,
4239        &subscription.consume().into_inner(),
4240    );
4241    *snapshot = new_snapshot;
4242}
4243
4244#[track_caller]
4245fn check_edits(
4246    old_snapshot: &MultiBufferSnapshot,
4247    new_snapshot: &MultiBufferSnapshot,
4248    edits: &[Edit<MultiBufferOffset>],
4249) {
4250    let mut text = old_snapshot.text();
4251    let new_text = new_snapshot.text();
4252    for edit in edits.iter().rev() {
4253        if !text.is_char_boundary(edit.old.start.0)
4254            || !text.is_char_boundary(edit.old.end.0)
4255            || !new_text.is_char_boundary(edit.new.start.0)
4256            || !new_text.is_char_boundary(edit.new.end.0)
4257        {
4258            panic!(
4259                "invalid edits: {:?}\nold text: {:?}\nnew text: {:?}",
4260                edits, text, new_text
4261            );
4262        }
4263
4264        text.replace_range(
4265            edit.old.start.0..edit.old.end.0,
4266            &new_text[edit.new.start.0..edit.new.end.0],
4267        );
4268    }
4269
4270    pretty_assertions::assert_eq!(text, new_text, "invalid edits: {:?}", edits);
4271}
4272
4273#[track_caller]
4274fn assert_chunks_in_ranges(snapshot: &MultiBufferSnapshot) {
4275    let full_text = snapshot.text();
4276    for ix in 0..full_text.len() {
4277        let mut chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4278        chunks.seek(MultiBufferOffset(ix)..snapshot.len());
4279        let tail = chunks.map(|chunk| chunk.text).collect::<String>();
4280        assert_eq!(tail, &full_text[ix..], "seek to range: {:?}", ix..);
4281    }
4282}
4283
4284#[track_caller]
4285fn assert_consistent_line_numbers(snapshot: &MultiBufferSnapshot) {
4286    let all_line_numbers = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
4287    for start_row in 1..all_line_numbers.len() {
4288        let line_numbers = snapshot
4289            .row_infos(MultiBufferRow(start_row as u32))
4290            .collect::<Vec<_>>();
4291        assert_eq!(
4292            line_numbers,
4293            all_line_numbers[start_row..],
4294            "start_row: {start_row}"
4295        );
4296    }
4297}
4298
4299#[track_caller]
4300fn assert_position_translation(snapshot: &MultiBufferSnapshot) {
4301    let text = Rope::from(snapshot.text());
4302
4303    let mut left_anchors = Vec::new();
4304    let mut right_anchors = Vec::new();
4305    let mut offsets = Vec::new();
4306    let mut points = Vec::new();
4307    for offset in 0..=text.len() + 1 {
4308        let offset = MultiBufferOffset(offset);
4309        let clipped_left = snapshot.clip_offset(offset, Bias::Left);
4310        let clipped_right = snapshot.clip_offset(offset, Bias::Right);
4311        assert_eq!(
4312            clipped_left.0,
4313            text.clip_offset(offset.0, Bias::Left),
4314            "clip_offset({offset:?}, Left)"
4315        );
4316        assert_eq!(
4317            clipped_right.0,
4318            text.clip_offset(offset.0, Bias::Right),
4319            "clip_offset({offset:?}, Right)"
4320        );
4321        assert_eq!(
4322            snapshot.offset_to_point(clipped_left),
4323            text.offset_to_point(clipped_left.0),
4324            "offset_to_point({})",
4325            clipped_left.0
4326        );
4327        assert_eq!(
4328            snapshot.offset_to_point(clipped_right),
4329            text.offset_to_point(clipped_right.0),
4330            "offset_to_point({})",
4331            clipped_right.0
4332        );
4333        let anchor_after = snapshot.anchor_after(clipped_left);
4334        assert_eq!(
4335            anchor_after.to_offset(snapshot),
4336            clipped_left,
4337            "anchor_after({}).to_offset {anchor_after:?}",
4338            clipped_left.0
4339        );
4340        let anchor_before = snapshot.anchor_before(clipped_left);
4341        assert_eq!(
4342            anchor_before.to_offset(snapshot),
4343            clipped_left,
4344            "anchor_before({}).to_offset",
4345            clipped_left.0
4346        );
4347        left_anchors.push(anchor_before);
4348        right_anchors.push(anchor_after);
4349        offsets.push(clipped_left);
4350        points.push(text.offset_to_point(clipped_left.0));
4351    }
4352
4353    for row in 0..text.max_point().row {
4354        for column in 0..text.line_len(row) + 1 {
4355            let point = Point { row, column };
4356            let clipped_left = snapshot.clip_point(point, Bias::Left);
4357            let clipped_right = snapshot.clip_point(point, Bias::Right);
4358            assert_eq!(
4359                clipped_left,
4360                text.clip_point(point, Bias::Left),
4361                "clip_point({point:?}, Left)"
4362            );
4363            assert_eq!(
4364                clipped_right,
4365                text.clip_point(point, Bias::Right),
4366                "clip_point({point:?}, Right)"
4367            );
4368            assert_eq!(
4369                snapshot.point_to_offset(clipped_left).0,
4370                text.point_to_offset(clipped_left),
4371                "point_to_offset({clipped_left:?})"
4372            );
4373            assert_eq!(
4374                snapshot.point_to_offset(clipped_right).0,
4375                text.point_to_offset(clipped_right),
4376                "point_to_offset({clipped_right:?})"
4377            );
4378        }
4379    }
4380
4381    assert_eq!(
4382        snapshot.summaries_for_anchors::<MultiBufferOffset, _>(&left_anchors),
4383        offsets,
4384        "left_anchors <-> offsets"
4385    );
4386    assert_eq!(
4387        snapshot.summaries_for_anchors::<Point, _>(&left_anchors),
4388        points,
4389        "left_anchors <-> points"
4390    );
4391    assert_eq!(
4392        snapshot.summaries_for_anchors::<MultiBufferOffset, _>(&right_anchors),
4393        offsets,
4394        "right_anchors <-> offsets"
4395    );
4396    assert_eq!(
4397        snapshot.summaries_for_anchors::<Point, _>(&right_anchors),
4398        points,
4399        "right_anchors <-> points"
4400    );
4401
4402    for (anchors, bias) in [(&left_anchors, Bias::Left), (&right_anchors, Bias::Right)] {
4403        for (ix, (offset, anchor)) in offsets.iter().zip(anchors).enumerate() {
4404            if ix > 0 && *offset == MultiBufferOffset(252) && offset > &offsets[ix - 1] {
4405                let prev_anchor = left_anchors[ix - 1];
4406                assert!(
4407                    anchor.cmp(&prev_anchor, snapshot).is_gt(),
4408                    "anchor({}, {bias:?}).cmp(&anchor({}, {bias:?}).is_gt()",
4409                    offsets[ix],
4410                    offsets[ix - 1],
4411                );
4412                assert!(
4413                    prev_anchor.cmp(anchor, snapshot).is_lt(),
4414                    "anchor({}, {bias:?}).cmp(&anchor({}, {bias:?}).is_lt()",
4415                    offsets[ix - 1],
4416                    offsets[ix],
4417                );
4418            }
4419        }
4420    }
4421
4422    if let Some((buffer, offset)) = snapshot.point_to_buffer_offset(snapshot.max_point()) {
4423        assert!(offset.0 <= buffer.len());
4424    }
4425    if let Some((buffer, point)) = snapshot.point_to_buffer_point(snapshot.max_point()) {
4426        assert!(point <= buffer.max_point());
4427    }
4428}
4429
4430fn assert_line_indents(snapshot: &MultiBufferSnapshot) {
4431    let max_row = snapshot.max_point().row;
4432    let buffer_id = snapshot.excerpts().next().unwrap().1.remote_id();
4433    let text = text::Buffer::new(ReplicaId::LOCAL, buffer_id, snapshot.text());
4434    let mut line_indents = text
4435        .line_indents_in_row_range(0..max_row + 1)
4436        .collect::<Vec<_>>();
4437    for start_row in 0..snapshot.max_point().row {
4438        pretty_assertions::assert_eq!(
4439            snapshot
4440                .line_indents(MultiBufferRow(start_row), |_| true)
4441                .map(|(row, indent, _)| (row.0, indent))
4442                .collect::<Vec<_>>(),
4443            &line_indents[(start_row as usize)..],
4444            "line_indents({start_row})"
4445        );
4446    }
4447
4448    line_indents.reverse();
4449    pretty_assertions::assert_eq!(
4450        snapshot
4451            .reversed_line_indents(MultiBufferRow(max_row), |_| true)
4452            .map(|(row, indent, _)| (row.0, indent))
4453            .collect::<Vec<_>>(),
4454        &line_indents[..],
4455        "reversed_line_indents({max_row})"
4456    );
4457}
4458
4459#[gpui::test]
4460fn test_new_empty_buffer_uses_untitled_title(cx: &mut App) {
4461    let buffer = cx.new(|cx| Buffer::local("", cx));
4462    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4463
4464    assert_eq!(multibuffer.read(cx).title(cx), "untitled");
4465}
4466
4467#[gpui::test]
4468fn test_new_empty_buffer_uses_untitled_title_when_only_contains_whitespace(cx: &mut App) {
4469    let buffer = cx.new(|cx| Buffer::local("\n ", cx));
4470    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4471
4472    assert_eq!(multibuffer.read(cx).title(cx), "untitled");
4473}
4474
4475#[gpui::test]
4476fn test_new_empty_buffer_takes_first_line_for_title(cx: &mut App) {
4477    let buffer = cx.new(|cx| Buffer::local("Hello World\nSecond line", cx));
4478    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4479
4480    assert_eq!(multibuffer.read(cx).title(cx), "Hello World");
4481}
4482
4483#[gpui::test]
4484fn test_new_empty_buffer_takes_trimmed_first_line_for_title(cx: &mut App) {
4485    let buffer = cx.new(|cx| Buffer::local("\nHello, World ", cx));
4486    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4487
4488    assert_eq!(multibuffer.read(cx).title(cx), "Hello, World");
4489}
4490
4491#[gpui::test]
4492fn test_new_empty_buffer_uses_truncated_first_line_for_title(cx: &mut App) {
4493    let title = "aaaaaaaaaabbbbbbbbbbccccccccccddddddddddeeeeeeeeee";
4494    let title_after = "aaaaaaaaaabbbbbbbbbbccccccccccdddddddddd";
4495    let buffer = cx.new(|cx| Buffer::local(title, cx));
4496    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4497
4498    assert_eq!(multibuffer.read(cx).title(cx), title_after);
4499}
4500
4501#[gpui::test]
4502fn test_new_empty_buffer_uses_truncated_first_line_for_title_after_merging_adjacent_spaces(
4503    cx: &mut App,
4504) {
4505    let title = "aaaaaaaaaabbbbbbbbbb    ccccccccccddddddddddeeeeeeeeee";
4506    let title_after = "aaaaaaaaaabbbbbbbbbb ccccccccccddddddddd";
4507    let buffer = cx.new(|cx| Buffer::local(title, cx));
4508    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4509
4510    assert_eq!(multibuffer.read(cx).title(cx), title_after);
4511}
4512
4513#[gpui::test]
4514fn test_new_empty_buffers_title_can_be_set(cx: &mut App) {
4515    let buffer = cx.new(|cx| Buffer::local("Hello World", cx));
4516    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4517    assert_eq!(multibuffer.read(cx).title(cx), "Hello World");
4518
4519    multibuffer.update(cx, |multibuffer, cx| {
4520        multibuffer.set_title("Hey".into(), cx)
4521    });
4522    assert_eq!(multibuffer.read(cx).title(cx), "Hey");
4523}
4524
4525#[gpui::test(iterations = 100)]
4526fn test_random_chunk_bitmaps(cx: &mut App, mut rng: StdRng) {
4527    let multibuffer = if rng.random() {
4528        let len = rng.random_range(0..10000);
4529        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
4530        let buffer = cx.new(|cx| Buffer::local(text, cx));
4531        cx.new(|cx| MultiBuffer::singleton(buffer, cx))
4532    } else {
4533        MultiBuffer::build_random(&mut rng, cx)
4534    };
4535
4536    let snapshot = multibuffer.read(cx).snapshot(cx);
4537
4538    let chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4539
4540    for chunk in chunks {
4541        let chunk_text = chunk.text;
4542        let chars_bitmap = chunk.chars;
4543        let tabs_bitmap = chunk.tabs;
4544
4545        if chunk_text.is_empty() {
4546            assert_eq!(
4547                chars_bitmap, 0,
4548                "Empty chunk should have empty chars bitmap"
4549            );
4550            assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
4551            continue;
4552        }
4553
4554        assert!(
4555            chunk_text.len() <= 128,
4556            "Chunk text length {} exceeds 128 bytes",
4557            chunk_text.len()
4558        );
4559
4560        // Verify chars bitmap
4561        let char_indices = chunk_text
4562            .char_indices()
4563            .map(|(i, _)| i)
4564            .collect::<Vec<_>>();
4565
4566        for byte_idx in 0..chunk_text.len() {
4567            let should_have_bit = char_indices.contains(&byte_idx);
4568            let has_bit = chars_bitmap & (1 << byte_idx) != 0;
4569
4570            if has_bit != should_have_bit {
4571                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4572                eprintln!("Char indices: {:?}", char_indices);
4573                eprintln!("Chars bitmap: {:#b}", chars_bitmap);
4574            }
4575
4576            assert_eq!(
4577                has_bit, should_have_bit,
4578                "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
4579                byte_idx, chunk_text, should_have_bit, has_bit
4580            );
4581        }
4582
4583        for (byte_idx, byte) in chunk_text.bytes().enumerate() {
4584            let is_tab = byte == b'\t';
4585            let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
4586
4587            if has_bit != is_tab {
4588                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4589                eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
4590                assert_eq!(
4591                    has_bit, is_tab,
4592                    "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
4593                    byte_idx, chunk_text, byte as char, is_tab, has_bit
4594                );
4595            }
4596        }
4597    }
4598}
4599
4600#[gpui::test(iterations = 10)]
4601fn test_random_chunk_bitmaps_with_diffs(cx: &mut App, mut rng: StdRng) {
4602    let settings_store = SettingsStore::test(cx);
4603    cx.set_global(settings_store);
4604    use buffer_diff::BufferDiff;
4605    use util::RandomCharIter;
4606
4607    let multibuffer = if rng.random() {
4608        let len = rng.random_range(100..10000);
4609        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
4610        let buffer = cx.new(|cx| Buffer::local(text, cx));
4611        cx.new(|cx| MultiBuffer::singleton(buffer, cx))
4612    } else {
4613        MultiBuffer::build_random(&mut rng, cx)
4614    };
4615
4616    let _diff_count = rng.random_range(1..5);
4617    let mut diffs = Vec::new();
4618
4619    multibuffer.update(cx, |multibuffer, cx| {
4620        for buffer_id in multibuffer.excerpt_buffer_ids() {
4621            if rng.random_bool(0.7) {
4622                if let Some(buffer_handle) = multibuffer.buffer(buffer_id) {
4623                    let buffer_text = buffer_handle.read(cx).text();
4624                    let mut base_text = String::new();
4625
4626                    for line in buffer_text.lines() {
4627                        if rng.random_bool(0.3) {
4628                            continue;
4629                        } else if rng.random_bool(0.3) {
4630                            let line_len = rng.random_range(0..50);
4631                            let modified_line = RandomCharIter::new(&mut rng)
4632                                .take(line_len)
4633                                .collect::<String>();
4634                            base_text.push_str(&modified_line);
4635                            base_text.push('\n');
4636                        } else {
4637                            base_text.push_str(line);
4638                            base_text.push('\n');
4639                        }
4640                    }
4641
4642                    if rng.random_bool(0.5) {
4643                        let extra_lines = rng.random_range(1..5);
4644                        for _ in 0..extra_lines {
4645                            let line_len = rng.random_range(0..50);
4646                            let extra_line = RandomCharIter::new(&mut rng)
4647                                .take(line_len)
4648                                .collect::<String>();
4649                            base_text.push_str(&extra_line);
4650                            base_text.push('\n');
4651                        }
4652                    }
4653
4654                    let diff = cx.new(|cx| {
4655                        BufferDiff::new_with_base_text(
4656                            &base_text,
4657                            &buffer_handle.read(cx).text_snapshot(),
4658                            cx,
4659                        )
4660                    });
4661                    diffs.push(diff.clone());
4662                    multibuffer.add_diff(diff, cx);
4663                }
4664            }
4665        }
4666    });
4667
4668    multibuffer.update(cx, |multibuffer, cx| {
4669        if rng.random_bool(0.5) {
4670            multibuffer.set_all_diff_hunks_expanded(cx);
4671        } else {
4672            let snapshot = multibuffer.snapshot(cx);
4673            let text = snapshot.text();
4674
4675            let mut ranges = Vec::new();
4676            for _ in 0..rng.random_range(1..5) {
4677                if snapshot.len().0 == 0 {
4678                    break;
4679                }
4680
4681                let diff_size = rng.random_range(5..1000);
4682                let mut start = rng.random_range(0..snapshot.len().0);
4683
4684                while !text.is_char_boundary(start) {
4685                    start = start.saturating_sub(1);
4686                }
4687
4688                let mut end = rng.random_range(start..snapshot.len().0.min(start + diff_size));
4689
4690                while !text.is_char_boundary(end) {
4691                    end = end.saturating_add(1);
4692                }
4693                let start_anchor = snapshot.anchor_after(MultiBufferOffset(start));
4694                let end_anchor = snapshot.anchor_before(MultiBufferOffset(end));
4695                ranges.push(start_anchor..end_anchor);
4696            }
4697            multibuffer.expand_diff_hunks(ranges, cx);
4698        }
4699    });
4700
4701    let snapshot = multibuffer.read(cx).snapshot(cx);
4702
4703    let chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4704
4705    for chunk in chunks {
4706        let chunk_text = chunk.text;
4707        let chars_bitmap = chunk.chars;
4708        let tabs_bitmap = chunk.tabs;
4709
4710        if chunk_text.is_empty() {
4711            assert_eq!(
4712                chars_bitmap, 0,
4713                "Empty chunk should have empty chars bitmap"
4714            );
4715            assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
4716            continue;
4717        }
4718
4719        assert!(
4720            chunk_text.len() <= 128,
4721            "Chunk text length {} exceeds 128 bytes",
4722            chunk_text.len()
4723        );
4724
4725        let char_indices = chunk_text
4726            .char_indices()
4727            .map(|(i, _)| i)
4728            .collect::<Vec<_>>();
4729
4730        for byte_idx in 0..chunk_text.len() {
4731            let should_have_bit = char_indices.contains(&byte_idx);
4732            let has_bit = chars_bitmap & (1 << byte_idx) != 0;
4733
4734            if has_bit != should_have_bit {
4735                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4736                eprintln!("Char indices: {:?}", char_indices);
4737                eprintln!("Chars bitmap: {:#b}", chars_bitmap);
4738            }
4739
4740            assert_eq!(
4741                has_bit, should_have_bit,
4742                "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
4743                byte_idx, chunk_text, should_have_bit, has_bit
4744            );
4745        }
4746
4747        for (byte_idx, byte) in chunk_text.bytes().enumerate() {
4748            let is_tab = byte == b'\t';
4749            let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
4750
4751            if has_bit != is_tab {
4752                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4753                eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
4754                assert_eq!(
4755                    has_bit, is_tab,
4756                    "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
4757                    byte_idx, chunk_text, byte as char, is_tab, has_bit
4758                );
4759            }
4760        }
4761    }
4762}
4763
4764fn collect_word_diffs(
4765    base_text: &str,
4766    modified_text: &str,
4767    cx: &mut TestAppContext,
4768) -> Vec<String> {
4769    let buffer = cx.new(|cx| Buffer::local(modified_text, cx));
4770    let diff = cx
4771        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
4772    cx.run_until_parked();
4773
4774    let multibuffer = cx.new(|cx| {
4775        let mut multibuffer = MultiBuffer::singleton(buffer.clone(), cx);
4776        multibuffer.add_diff(diff.clone(), cx);
4777        multibuffer
4778    });
4779
4780    multibuffer.update(cx, |multibuffer, cx| {
4781        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
4782    });
4783
4784    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
4785    let text = snapshot.text();
4786
4787    snapshot
4788        .diff_hunks()
4789        .flat_map(|hunk| hunk.word_diffs)
4790        .map(|range| text[range.start.0..range.end.0].to_string())
4791        .collect()
4792}
4793
4794#[gpui::test]
4795async fn test_word_diff_simple_replacement(cx: &mut TestAppContext) {
4796    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4797    cx.set_global(settings_store);
4798
4799    let base_text = "hello world foo bar\n";
4800    let modified_text = "hello WORLD foo BAR\n";
4801
4802    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4803
4804    assert_eq!(word_diffs, vec!["world", "bar", "WORLD", "BAR"]);
4805}
4806
4807#[gpui::test]
4808async fn test_word_diff_white_space(cx: &mut TestAppContext) {
4809    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4810    cx.set_global(settings_store);
4811
4812    let base_text = "hello world foo bar\n";
4813    let modified_text = "    hello world foo bar\n";
4814
4815    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4816
4817    assert_eq!(word_diffs, vec!["    "]);
4818}
4819
4820#[gpui::test]
4821async fn test_word_diff_consecutive_modified_lines(cx: &mut TestAppContext) {
4822    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4823    cx.set_global(settings_store);
4824
4825    let base_text = "aaa bbb\nccc ddd\n";
4826    let modified_text = "aaa BBB\nccc DDD\n";
4827
4828    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4829
4830    assert_eq!(
4831        word_diffs,
4832        vec!["bbb", "ddd", "BBB", "DDD"],
4833        "consecutive modified lines should produce word diffs when line counts match"
4834    );
4835}
4836
4837#[gpui::test]
4838async fn test_word_diff_modified_lines_with_deletion_between(cx: &mut TestAppContext) {
4839    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4840    cx.set_global(settings_store);
4841
4842    let base_text = "aaa bbb\ndeleted line\nccc ddd\n";
4843    let modified_text = "aaa BBB\nccc DDD\n";
4844
4845    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4846
4847    assert_eq!(
4848        word_diffs,
4849        Vec::<String>::new(),
4850        "modified lines with a deleted line between should not produce word diffs"
4851    );
4852}
4853
4854#[gpui::test]
4855async fn test_word_diff_disabled(cx: &mut TestAppContext) {
4856    let settings_store = cx.update(|cx| {
4857        let mut settings_store = SettingsStore::test(cx);
4858        settings_store.update_user_settings(cx, |settings| {
4859            settings.project.all_languages.defaults.word_diff_enabled = Some(false);
4860        });
4861        settings_store
4862    });
4863    cx.set_global(settings_store);
4864
4865    let base_text = "hello world\n";
4866    let modified_text = "hello WORLD\n";
4867
4868    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4869
4870    assert_eq!(
4871        word_diffs,
4872        Vec::<String>::new(),
4873        "word diffs should be empty when disabled"
4874    );
4875}
4876
4877/// Tests `excerpt_containing` and `excerpts_for_range` (functions mapping multi-buffer text-coordinates to excerpts)
4878#[gpui::test]
4879fn test_excerpts_containment_functions(cx: &mut App) {
4880    // Multibuffer content for these tests:
4881    //    0123
4882    // 0: aa0
4883    // 1: aa1
4884    //    -----
4885    // 2: bb0
4886    // 3: bb1
4887    //    -----MultiBufferOffset(0)..
4888    // 4: cc0
4889
4890    let buffer_1 = cx.new(|cx| Buffer::local("aa0\naa1", cx));
4891    let buffer_2 = cx.new(|cx| Buffer::local("bb0\nbb1", cx));
4892    let buffer_3 = cx.new(|cx| Buffer::local("cc0", cx));
4893
4894    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
4895
4896    let (excerpt_1_info, excerpt_2_info, excerpt_3_info) =
4897        multibuffer.update(cx, |multibuffer, cx| {
4898            multibuffer.set_excerpts_for_path(
4899                PathKey::sorted(0),
4900                buffer_1.clone(),
4901                [Point::new(0, 0)..Point::new(1, 3)],
4902                0,
4903                cx,
4904            );
4905
4906            multibuffer.set_excerpts_for_path(
4907                PathKey::sorted(1),
4908                buffer_2.clone(),
4909                [Point::new(0, 0)..Point::new(1, 3)],
4910                0,
4911                cx,
4912            );
4913
4914            multibuffer.set_excerpts_for_path(
4915                PathKey::sorted(2),
4916                buffer_3.clone(),
4917                [Point::new(0, 0)..Point::new(0, 3)],
4918                0,
4919                cx,
4920            );
4921
4922            let snapshot = multibuffer.snapshot(cx);
4923            let mut infos = snapshot.excerpts().map(|(_, info)| info);
4924            (
4925                infos.next().unwrap(),
4926                infos.next().unwrap(),
4927                infos.next().unwrap(),
4928            )
4929        });
4930
4931    let snapshot = multibuffer.read(cx).snapshot(cx);
4932
4933    assert_eq!(snapshot.text(), "aa0\naa1\nbb0\nbb1\ncc0");
4934
4935    //// Test `excerpts_for_range`
4936
4937    let p00 = snapshot.point_to_offset(Point::new(0, 0));
4938    let p10 = snapshot.point_to_offset(Point::new(1, 0));
4939    let p20 = snapshot.point_to_offset(Point::new(2, 0));
4940    let p23 = snapshot.point_to_offset(Point::new(2, 3));
4941    let p13 = snapshot.point_to_offset(Point::new(1, 3));
4942    let p40 = snapshot.point_to_offset(Point::new(4, 0));
4943    let p43 = snapshot.point_to_offset(Point::new(4, 3));
4944
4945    let excerpts: Vec<_> = snapshot.excerpts_for_range(p00..p00).collect();
4946    assert_eq!(excerpts.len(), 1);
4947    assert_eq!(excerpts[0].info(), excerpt_1_info);
4948
4949    // Cursor at very end of excerpt 3
4950    let excerpts: Vec<_> = snapshot.excerpts_for_range(p43..p43).collect();
4951    assert_eq!(excerpts.len(), 1);
4952    assert_eq!(excerpts[0].info(), excerpt_3_info);
4953
4954    let excerpts: Vec<_> = snapshot.excerpts_for_range(p00..p23).collect();
4955    assert_eq!(excerpts.len(), 2);
4956    assert_eq!(excerpts[0].info(), excerpt_1_info);
4957    assert_eq!(excerpts[1].info(), excerpt_2_info);
4958
4959    // This range represent an selection with end-point just inside excerpt_2
4960    // Today we only expand the first excerpt, but another interpretation that
4961    // we could consider is expanding both here
4962    let excerpts: Vec<_> = snapshot.excerpts_for_range(p10..p20).collect();
4963    assert_eq!(excerpts.len(), 1);
4964    assert_eq!(excerpts[0].info(), excerpt_1_info);
4965
4966    //// Test that `excerpts_for_range` and `excerpt_containing` agree for all single offsets (cursor positions)
4967    for offset in 0..=snapshot.len().0 {
4968        let offset = MultiBufferOffset(offset);
4969        let excerpts_for_range: Vec<_> = snapshot.excerpts_for_range(offset..offset).collect();
4970        assert_eq!(
4971            excerpts_for_range.len(),
4972            1,
4973            "Expected exactly one excerpt for offset {offset}",
4974        );
4975
4976        let excerpt_containing = snapshot.excerpt_containing(offset..offset);
4977        assert!(
4978            excerpt_containing.is_some(),
4979            "Expected excerpt_containing to find excerpt for offset {offset}",
4980        );
4981
4982        assert_eq!(
4983            excerpts_for_range[0].info(),
4984            excerpt_containing.unwrap().excerpt.info(),
4985            "excerpts_for_range and excerpt_containing should agree for offset {offset}",
4986        );
4987    }
4988
4989    //// Test `excerpt_containing` behavior with ranges:
4990
4991    // Ranges intersecting a single-excerpt
4992    let containing = snapshot.excerpt_containing(p00..p13);
4993    assert!(containing.is_some());
4994    assert_eq!(containing.unwrap().excerpt.info(), excerpt_1_info);
4995
4996    // Ranges intersecting multiple excerpts (should return None)
4997    let containing = snapshot.excerpt_containing(p20..p40);
4998    assert!(
4999        containing.is_none(),
5000        "excerpt_containing should return None for ranges spanning multiple excerpts"
5001    );
5002}
5003
5004#[gpui::test]
5005fn test_range_to_buffer_ranges_with_range_bounds(cx: &mut App) {
5006    use std::ops::Bound;
5007
5008    let buffer_1 = cx.new(|cx| Buffer::local("aaa\nbbb", cx));
5009    let buffer_2 = cx.new(|cx| Buffer::local("ccc", cx));
5010
5011    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5012    let (excerpt_1_id, excerpt_2_id) = multibuffer.update(cx, |multibuffer, cx| {
5013        multibuffer.set_excerpts_for_path(
5014            PathKey::sorted(0),
5015            buffer_1.clone(),
5016            [Point::new(0, 0)..Point::new(1, 3)],
5017            0,
5018            cx,
5019        );
5020
5021        multibuffer.set_excerpts_for_path(
5022            PathKey::sorted(1),
5023            buffer_2.clone(),
5024            [Point::new(0, 0)..Point::new(0, 3)],
5025            0,
5026            cx,
5027        );
5028
5029        let excerpt_ids = multibuffer.excerpt_ids();
5030
5031        (excerpt_ids[0], excerpt_ids[1])
5032    });
5033
5034    let snapshot = multibuffer.read(cx).snapshot(cx);
5035    assert_eq!(snapshot.text(), "aaa\nbbb\nccc");
5036
5037    let excerpt_2_start = Point::new(2, 0);
5038
5039    let ranges_half_open = snapshot.range_to_buffer_ranges(Point::zero()..excerpt_2_start);
5040    assert_eq!(
5041        ranges_half_open.len(),
5042        1,
5043        "Half-open range ending at excerpt start should EXCLUDE that excerpt"
5044    );
5045    assert_eq!(ranges_half_open[0].2, excerpt_1_id);
5046
5047    let ranges_inclusive = snapshot.range_to_buffer_ranges(Point::zero()..=excerpt_2_start);
5048    assert_eq!(
5049        ranges_inclusive.len(),
5050        2,
5051        "Inclusive range ending at excerpt start should INCLUDE that excerpt"
5052    );
5053    assert_eq!(ranges_inclusive[0].2, excerpt_1_id);
5054    assert_eq!(ranges_inclusive[1].2, excerpt_2_id);
5055
5056    let ranges_unbounded =
5057        snapshot.range_to_buffer_ranges((Bound::Included(Point::zero()), Bound::Unbounded));
5058    assert_eq!(
5059        ranges_unbounded.len(),
5060        2,
5061        "Unbounded end should include all excerpts"
5062    );
5063    assert_eq!(ranges_unbounded[0].2, excerpt_1_id);
5064    assert_eq!(ranges_unbounded[1].2, excerpt_2_id);
5065
5066    let ranges_excluded_end = snapshot.range_to_buffer_ranges((
5067        Bound::Included(Point::zero()),
5068        Bound::Excluded(excerpt_2_start),
5069    ));
5070    assert_eq!(
5071        ranges_excluded_end.len(),
5072        1,
5073        "Excluded end bound should exclude excerpt starting at that point"
5074    );
5075    assert_eq!(ranges_excluded_end[0].2, excerpt_1_id);
5076
5077    let buffer_empty = cx.new(|cx| Buffer::local("", cx));
5078    let multibuffer_trailing_empty = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5079    let (te_excerpt_1_info, te_excerpt_2_info) =
5080        multibuffer_trailing_empty.update(cx, |multibuffer, cx| {
5081            multibuffer.set_excerpts_for_path(
5082                PathKey::sorted(0),
5083                buffer_1.clone(),
5084                [Point::new(0, 0)..Point::new(1, 3)],
5085                0,
5086                cx,
5087            );
5088
5089            multibuffer.set_excerpts_for_path(
5090                PathKey::sorted(1),
5091                buffer_empty.clone(),
5092                [Point::new(0, 0)..Point::new(0, 0)],
5093                0,
5094                cx,
5095            );
5096
5097            let snapshot = multibuffer.snapshot(cx);
5098            let mut infos = snapshot.excerpts().map(|(_, info)| info);
5099            (infos.next().unwrap(), infos.next().unwrap())
5100        });
5101
5102    let snapshot_trailing = multibuffer_trailing_empty.read(cx).snapshot(cx);
5103    assert_eq!(snapshot_trailing.text(), "aaa\nbbb\n");
5104
5105    let max_point = snapshot_trailing.max_point();
5106
5107    let ranges_half_open_max =
5108        snapshot_trailing.range_to_buffer_ranges_with_context(Point::zero()..max_point);
5109    assert_eq!(
5110        ranges_half_open_max.len(),
5111        1,
5112        "Half-open range to max_point should EXCLUDE trailing empty excerpt at max_point"
5113    );
5114    assert_eq!(ranges_half_open_max[0].2, te_excerpt_1_info.range.context);
5115
5116    let ranges_inclusive_max =
5117        snapshot_trailing.range_to_buffer_ranges_with_context(Point::zero()..=max_point);
5118    assert_eq!(
5119        ranges_inclusive_max.len(),
5120        2,
5121        "Inclusive range to max_point should INCLUDE trailing empty excerpt"
5122    );
5123    assert_eq!(ranges_inclusive_max[0].2, te_excerpt_1_info.range.context);
5124    assert_eq!(ranges_inclusive_max[1].2, te_excerpt_2_info.range.context);
5125
5126    let ranges_unbounded_trailing = snapshot_trailing
5127        .range_to_buffer_ranges_with_context((Bound::Included(Point::zero()), Bound::Unbounded));
5128    assert_eq!(
5129        ranges_unbounded_trailing.len(),
5130        2,
5131        "Unbounded end should include trailing empty excerpt"
5132    );
5133    assert_eq!(
5134        ranges_unbounded_trailing[0].2,
5135        te_excerpt_1_info.range.context
5136    );
5137    assert_eq!(
5138        ranges_unbounded_trailing[1].2,
5139        te_excerpt_2_info.range.context
5140    );
5141}
5142
5143#[gpui::test]
5144fn test_cannot_seek_backward_after_excerpt_replacement(cx: &mut TestAppContext) {
5145    let buffer_b_text: String = (0..50).map(|i| format!("line_b {i}\n")).collect();
5146    let buffer_b = cx.new(|cx| Buffer::local(buffer_b_text, cx));
5147
5148    let buffer_c_text: String = (0..10).map(|i| format!("line_c {i}\n")).collect();
5149    let buffer_c = cx.new(|cx| Buffer::local(buffer_c_text, cx));
5150
5151    let buffer_d_text: String = (0..10).map(|i| format!("line_d {i}\n")).collect();
5152    let buffer_d = cx.new(|cx| Buffer::local(buffer_d_text, cx));
5153
5154    let path_b = PathKey::with_sort_prefix(0, rel_path("bbb.rs").into_arc());
5155    let path_c = PathKey::with_sort_prefix(0, rel_path("ddd.rs").into_arc());
5156    let path_d = PathKey::with_sort_prefix(0, rel_path("ccc.rs").into_arc());
5157
5158    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5159
5160    multibuffer.update(cx, |multibuffer, cx| {
5161        multibuffer.set_excerpts_for_path(
5162            path_b.clone(),
5163            buffer_b.clone(),
5164            vec![
5165                Point::row_range(0..3),
5166                Point::row_range(15..18),
5167                Point::row_range(30..33),
5168            ],
5169            0,
5170            cx,
5171        );
5172    });
5173
5174    multibuffer.update(cx, |multibuffer, cx| {
5175        multibuffer.set_excerpts_for_path(
5176            path_c.clone(),
5177            buffer_c.clone(),
5178            vec![Point::row_range(0..3)],
5179            0,
5180            cx,
5181        );
5182    });
5183
5184    let (anchor_in_e_b2, anchor_in_e_b3) = multibuffer.read_with(cx, |multibuffer, cx| {
5185        let snapshot = multibuffer.snapshot(cx);
5186        let excerpt_infos: Vec<ExcerptInfo> = snapshot.excerpts().map(|(_, info)| info).collect();
5187        assert_eq!(excerpt_infos.len(), 4, "expected 4 excerpts (3×B + 1×C)");
5188
5189        let e_b2_info = excerpt_infos[1].clone();
5190        let e_b3_info = excerpt_infos[2].clone();
5191
5192        let anchor_b2 = Anchor::in_buffer(e_b2_info.path_key_index, e_b2_info.range.context.start);
5193        let anchor_b3 = Anchor::in_buffer(e_b3_info.path_key_index, e_b3_info.range.context.start);
5194        (anchor_b2, anchor_b3)
5195    });
5196
5197    multibuffer.update(cx, |multibuffer, cx| {
5198        multibuffer.set_excerpts_for_path(
5199            path_b.clone(),
5200            buffer_b.clone(),
5201            vec![Point::row_range(0..3), Point::row_range(28..36)],
5202            0,
5203            cx,
5204        );
5205    });
5206
5207    multibuffer.update(cx, |multibuffer, cx| {
5208        multibuffer.set_excerpts_for_path(
5209            path_d.clone(),
5210            buffer_d.clone(),
5211            vec![Point::row_range(0..3)],
5212            0,
5213            cx,
5214        );
5215    });
5216
5217    multibuffer.read_with(cx, |multibuffer, cx| {
5218        let snapshot = multibuffer.snapshot(cx);
5219        snapshot.summaries_for_anchors::<Point, _>(&[anchor_in_e_b2, anchor_in_e_b3]);
5220    });
5221}