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(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(
 879            multibuffer
 880                .snapshot(cx)
 881                .excerpts()
 882                .map(|(_, info)| Anchor::in_buffer(info.path_key_index, info.range.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    expanded_diff_hunks_by_buffer: HashMap<BufferId, Vec<text::Anchor>>,
2272}
2273
2274#[derive(Debug)]
2275struct ReferenceExcerpt {
2276    path_key: PathKey,
2277    path_key_index: PathKeyIndex,
2278    buffer: Entity<Buffer>,
2279    range: Range<text::Anchor>,
2280}
2281
2282#[derive(Clone, Debug)]
2283struct ReferenceRegion {
2284    buffer_id: Option<BufferId>,
2285    range: Range<usize>,
2286    buffer_range: Option<Range<Point>>,
2287    status: Option<DiffHunkStatus>,
2288    excerpt_info: Option<ExcerptInfo>,
2289}
2290
2291impl ReferenceExcerpt {
2292    fn info(&self, cx: &App) -> ExcerptInfo {
2293        ExcerptInfo {
2294            path_key_index: self.path_key_index,
2295            buffer_id: self.buffer.read(cx).remote_id(),
2296            range: self.range.clone(),
2297        }
2298    }
2299}
2300
2301impl ReferenceMultibuffer {
2302    fn expand_excerpts(&mut self, excerpts: &HashSet<ExcerptInfo>, line_count: u32, cx: &App) {
2303        if line_count == 0 {
2304            return;
2305        }
2306
2307        for info in excerpts {
2308            let excerpt = self
2309                .excerpts
2310                .iter_mut()
2311                .find(|e| &e.info(cx) == info)
2312                .unwrap();
2313            let snapshot = excerpt.buffer.read(cx).snapshot();
2314            let mut point_range = excerpt.range.to_point(&snapshot);
2315            point_range.start = Point::new(point_range.start.row.saturating_sub(line_count), 0);
2316            point_range.end =
2317                snapshot.clip_point(Point::new(point_range.end.row + line_count, 0), Bias::Left);
2318            point_range.end.column = snapshot.line_len(point_range.end.row);
2319            excerpt.range =
2320                snapshot.anchor_before(point_range.start)..snapshot.anchor_after(point_range.end);
2321        }
2322    }
2323
2324    fn set_excerpts(
2325        &mut self,
2326        path_key: PathKey,
2327        path_key_index: PathKeyIndex,
2328        buffer: Entity<Buffer>,
2329        buffer_snapshot: &BufferSnapshot,
2330        ranges: Vec<ExcerptRange<Point>>,
2331    ) {
2332        self.excerpts.retain(|excerpt| {
2333            excerpt.path_key != path_key && excerpt.buffer.entity_id() != buffer.entity_id()
2334        });
2335
2336        let ranges = MultiBuffer::merge_excerpt_ranges(&ranges);
2337
2338        let (Ok(ix) | Err(ix)) = self
2339            .excerpts
2340            .binary_search_by(|probe| probe.path_key.cmp(&path_key));
2341        self.excerpts.splice(
2342            ix..ix,
2343            ranges.into_iter().map(|range| ReferenceExcerpt {
2344                path_key: path_key.clone(),
2345                path_key_index,
2346                buffer: buffer.clone(),
2347                range: buffer_snapshot.anchor_before(range.context.start)
2348                    ..buffer_snapshot.anchor_after(range.context.end),
2349            }),
2350        );
2351    }
2352
2353    fn expand_diff_hunks(&mut self, path_key: PathKey, range: Range<text::Anchor>, cx: &App) {
2354        let excerpt = self
2355            .excerpts
2356            .iter_mut()
2357            .find(|e| {
2358                e.path_key == path_key
2359                    && e.range
2360                        .start
2361                        .cmp(&range.start, &e.buffer.read(cx).snapshot())
2362                        .is_le()
2363            })
2364            .unwrap();
2365        let buffer = excerpt.buffer.read(cx).snapshot();
2366        let buffer_id = buffer.remote_id();
2367
2368        // Skip inverted excerpts - hunks are always expanded
2369        if self.inverted_diffs.contains_key(&buffer_id) {
2370            return;
2371        }
2372
2373        let Some(diff) = self.diffs.get(&buffer_id) else {
2374            return;
2375        };
2376        let excerpt_range = excerpt.range.to_offset(&buffer);
2377        let expanded_diff_hunks = self
2378            .expanded_diff_hunks_by_buffer
2379            .entry(buffer_id)
2380            .or_default();
2381        for hunk in diff
2382            .read(cx)
2383            .snapshot(cx)
2384            .hunks_intersecting_range(range, &buffer)
2385        {
2386            let hunk_range = hunk.buffer_range.to_offset(&buffer);
2387            if hunk_range.start < excerpt_range.start || hunk_range.start > excerpt_range.end {
2388                continue;
2389            }
2390            if let Err(ix) = expanded_diff_hunks
2391                .binary_search_by(|anchor| anchor.cmp(&hunk.buffer_range.start, &buffer))
2392            {
2393                log::info!(
2394                    "expanding diff hunk {:?}. excerpt range:{:?}",
2395                    hunk_range,
2396                    excerpt_range
2397                );
2398                expanded_diff_hunks.insert(ix, hunk.buffer_range.start);
2399            } else {
2400                log::trace!("hunk {hunk_range:?} already expanded in excerpt");
2401            }
2402        }
2403    }
2404
2405    fn expected_content(&self, cx: &App) -> (String, Vec<RowInfo>, HashSet<MultiBufferRow>) {
2406        let mut text = String::new();
2407        let mut regions = Vec::<ReferenceRegion>::new();
2408        let mut excerpt_boundary_rows = HashSet::default();
2409        for excerpt in &self.excerpts {
2410            excerpt_boundary_rows.insert(MultiBufferRow(text.matches('\n').count() as u32));
2411            let buffer = excerpt.buffer.read(cx);
2412            let buffer_id = buffer.remote_id();
2413            let buffer_range = excerpt.range.to_offset(buffer);
2414
2415            if let Some((diff, main_buffer)) = self.inverted_diffs.get(&buffer_id) {
2416                let diff_snapshot = diff.read(cx).snapshot(cx);
2417                let main_buffer_snapshot = main_buffer.read(cx).snapshot();
2418
2419                let mut offset = buffer_range.start;
2420                for hunk in diff_snapshot.hunks_intersecting_base_text_range(
2421                    buffer_range.clone(),
2422                    &main_buffer_snapshot.text,
2423                ) {
2424                    let mut hunk_base_range = hunk.diff_base_byte_range.clone();
2425
2426                    hunk_base_range.end = hunk_base_range.end.min(buffer_range.end);
2427                    if hunk_base_range.start > buffer_range.end
2428                        || hunk_base_range.start < buffer_range.start
2429                    {
2430                        continue;
2431                    }
2432
2433                    // Add the text before the hunk
2434                    if hunk_base_range.start >= offset {
2435                        let len = text.len();
2436                        text.extend(buffer.text_for_range(offset..hunk_base_range.start));
2437                        if text.len() > len {
2438                            regions.push(ReferenceRegion {
2439                                buffer_id: Some(buffer_id),
2440                                range: len..text.len(),
2441                                buffer_range: Some(
2442                                    (offset..hunk_base_range.start).to_point(&buffer),
2443                                ),
2444                                status: None,
2445                                excerpt_info: Some(excerpt.info(cx)),
2446                            });
2447                        }
2448                    }
2449
2450                    // Add the "deleted" region (base text that's not in main)
2451                    if !hunk_base_range.is_empty() {
2452                        let len = text.len();
2453                        text.extend(buffer.text_for_range(hunk_base_range.clone()));
2454                        regions.push(ReferenceRegion {
2455                            buffer_id: Some(buffer_id),
2456                            range: len..text.len(),
2457                            buffer_range: Some(hunk_base_range.to_point(&buffer)),
2458                            status: Some(DiffHunkStatus::deleted(hunk.secondary_status)),
2459                            excerpt_info: Some(excerpt.info(cx)),
2460                        });
2461                    }
2462
2463                    offset = hunk_base_range.end;
2464                }
2465
2466                // Add remaining buffer text
2467                let len = text.len();
2468                text.extend(buffer.text_for_range(offset..buffer_range.end));
2469                text.push('\n');
2470                regions.push(ReferenceRegion {
2471                    buffer_id: Some(buffer_id),
2472                    range: len..text.len(),
2473                    buffer_range: Some((offset..buffer_range.end).to_point(&buffer)),
2474                    status: None,
2475                    excerpt_info: Some(excerpt.info(cx)),
2476                });
2477            } else {
2478                let diff = self.diffs.get(&buffer_id).unwrap().read(cx).snapshot(cx);
2479                let base_buffer = diff.base_text();
2480
2481                let mut offset = buffer_range.start;
2482                let hunks = diff
2483                    .hunks_intersecting_range(excerpt.range.clone(), buffer)
2484                    .peekable();
2485
2486                for hunk in hunks {
2487                    // Ignore hunks that are outside the excerpt range.
2488                    let mut hunk_range = hunk.buffer_range.to_offset(buffer);
2489
2490                    hunk_range.end = hunk_range.end.min(buffer_range.end);
2491                    if hunk_range.start > buffer_range.end || hunk_range.start < buffer_range.start
2492                    {
2493                        log::trace!("skipping hunk outside excerpt range");
2494                        continue;
2495                    }
2496
2497                    if !self
2498                        .expanded_diff_hunks_by_buffer
2499                        .get(&buffer_id)
2500                        .cloned()
2501                        .into_iter()
2502                        .flatten()
2503                        .any(|expanded_anchor| {
2504                            expanded_anchor.to_offset(buffer).max(buffer_range.start)
2505                                == hunk_range.start.max(buffer_range.start)
2506                        })
2507                    {
2508                        log::trace!("skipping a hunk that's not marked as expanded");
2509                        continue;
2510                    }
2511
2512                    if !hunk.buffer_range.start.is_valid(buffer) {
2513                        log::trace!("skipping hunk with deleted start: {:?}", hunk.range);
2514                        continue;
2515                    }
2516
2517                    if hunk_range.start >= offset {
2518                        // Add the buffer text before the hunk
2519                        let len = text.len();
2520                        text.extend(buffer.text_for_range(offset..hunk_range.start));
2521                        if text.len() > len {
2522                            regions.push(ReferenceRegion {
2523                                buffer_id: Some(buffer_id),
2524                                range: len..text.len(),
2525                                buffer_range: Some((offset..hunk_range.start).to_point(&buffer)),
2526                                status: None,
2527                                excerpt_info: Some(excerpt.info(cx)),
2528                            });
2529                        }
2530
2531                        // Add the deleted text for the hunk.
2532                        if !hunk.diff_base_byte_range.is_empty() {
2533                            let mut base_text = base_buffer
2534                                .text_for_range(hunk.diff_base_byte_range.clone())
2535                                .collect::<String>();
2536                            if !base_text.ends_with('\n') {
2537                                base_text.push('\n');
2538                            }
2539                            let len = text.len();
2540                            text.push_str(&base_text);
2541                            regions.push(ReferenceRegion {
2542                                buffer_id: Some(base_buffer.remote_id()),
2543                                range: len..text.len(),
2544                                buffer_range: Some(
2545                                    hunk.diff_base_byte_range.to_point(&base_buffer),
2546                                ),
2547                                status: Some(DiffHunkStatus::deleted(hunk.secondary_status)),
2548                                excerpt_info: Some(excerpt.info(cx)),
2549                            });
2550                        }
2551
2552                        offset = hunk_range.start;
2553                    }
2554
2555                    // Add the inserted text for the hunk.
2556                    if hunk_range.end > offset {
2557                        let len = text.len();
2558                        text.extend(buffer.text_for_range(offset..hunk_range.end));
2559                        let range = len..text.len();
2560                        let region = ReferenceRegion {
2561                            buffer_id: Some(buffer_id),
2562                            range,
2563                            buffer_range: Some((offset..hunk_range.end).to_point(&buffer)),
2564                            status: Some(DiffHunkStatus::added(hunk.secondary_status)),
2565                            excerpt_info: Some(excerpt.info(cx)),
2566                        };
2567                        offset = hunk_range.end;
2568                        regions.push(region);
2569                    }
2570                }
2571
2572                // Add the buffer text for the rest of the excerpt.
2573                let len = text.len();
2574                text.extend(buffer.text_for_range(offset..buffer_range.end));
2575                text.push('\n');
2576                regions.push(ReferenceRegion {
2577                    buffer_id: Some(buffer_id),
2578                    range: len..text.len(),
2579                    buffer_range: Some((offset..buffer_range.end).to_point(&buffer)),
2580                    status: None,
2581                    excerpt_info: Some(excerpt.info(cx)),
2582                });
2583            }
2584        }
2585
2586        // Remove final trailing newline.
2587        if self.excerpts.is_empty() {
2588            regions.push(ReferenceRegion {
2589                buffer_id: None,
2590                range: 0..1,
2591                buffer_range: Some(Point::new(0, 0)..Point::new(0, 1)),
2592                status: None,
2593                excerpt_info: None,
2594            });
2595        } else {
2596            text.pop();
2597        }
2598
2599        // Retrieve the row info using the region that contains
2600        // the start of each multi-buffer line.
2601        let mut ix = 0;
2602        let row_infos = text
2603            .split('\n')
2604            .map(|line| {
2605                let row_info = regions
2606                    .iter()
2607                    .position(|region| region.range.contains(&ix))
2608                    .map_or(RowInfo::default(), |region_ix| {
2609                        let region = regions[region_ix].clone();
2610                        let buffer_row = region.buffer_range.as_ref().map(|buffer_range| {
2611                            buffer_range.start.row
2612                                + text[region.range.start..ix].matches('\n').count() as u32
2613                        });
2614                        let main_buffer = self
2615                            .excerpts
2616                            .iter()
2617                            .find(|e| e.info(cx) == region.excerpt_info.clone().unwrap())
2618                            .map(|e| e.buffer.clone());
2619                        let is_excerpt_start = region_ix == 0
2620                            || &regions[region_ix - 1].excerpt_info != &region.excerpt_info
2621                            || regions[region_ix - 1].range.is_empty();
2622                        let mut is_excerpt_end = region_ix == regions.len() - 1
2623                            || &regions[region_ix + 1].excerpt_info != &region.excerpt_info;
2624                        let is_start = !text[region.range.start..ix].contains('\n');
2625                        let mut is_end = if region.range.end > text.len() {
2626                            !text[ix..].contains('\n')
2627                        } else {
2628                            text[ix..region.range.end.min(text.len())]
2629                                .matches('\n')
2630                                .count()
2631                                == 1
2632                        };
2633                        if region_ix < regions.len() - 1
2634                            && !text[ix..].contains("\n")
2635                            && (region.status == Some(DiffHunkStatus::added_none())
2636                                || region.status.is_some_and(|s| s.is_deleted()))
2637                            && regions[region_ix + 1].excerpt_info == region.excerpt_info
2638                            && regions[region_ix + 1].range.start == text.len()
2639                        {
2640                            is_end = true;
2641                            is_excerpt_end = true;
2642                        }
2643                        let multibuffer_row =
2644                            MultiBufferRow(text[..ix].matches('\n').count() as u32);
2645                        let mut expand_direction = None;
2646                        if let Some(buffer) = &main_buffer {
2647                            let buffer_row = buffer_row.unwrap();
2648                            let needs_expand_up = is_excerpt_start && is_start && buffer_row > 0;
2649                            let needs_expand_down = is_excerpt_end
2650                                && is_end
2651                                && buffer.read(cx).max_point().row > buffer_row;
2652                            expand_direction = if needs_expand_up && needs_expand_down {
2653                                Some(ExpandExcerptDirection::UpAndDown)
2654                            } else if needs_expand_up {
2655                                Some(ExpandExcerptDirection::Up)
2656                            } else if needs_expand_down {
2657                                Some(ExpandExcerptDirection::Down)
2658                            } else {
2659                                None
2660                            };
2661                        }
2662                        RowInfo {
2663                            buffer_id: region.buffer_id,
2664                            diff_status: region.status,
2665                            buffer_row,
2666                            wrapped_buffer_row: None,
2667
2668                            multibuffer_row: Some(multibuffer_row),
2669                            expand_info: expand_direction.zip(region.excerpt_info.clone()).map(
2670                                |(direction, excerpt_info)| ExpandInfo {
2671                                    direction,
2672                                    excerpt_range: excerpt_info.range,
2673                                },
2674                            ),
2675                        }
2676                    });
2677                ix += line.len() + 1;
2678                row_info
2679            })
2680            .collect();
2681
2682        (text, row_infos, excerpt_boundary_rows)
2683    }
2684
2685    fn diffs_updated(&mut self, cx: &App) {
2686        for excerpt in &mut self.excerpts {
2687            let buffer = excerpt.buffer.read(cx).snapshot();
2688            let buffer_id = buffer.remote_id();
2689
2690            // Skip inverted diff excerpts - hunks are always expanded
2691            if self.inverted_diffs.contains_key(&buffer_id) {
2692                continue;
2693            }
2694
2695            let excerpt_range = excerpt.range.to_offset(&buffer);
2696            let Some(diff) = self.diffs.get(&buffer_id) else {
2697                continue;
2698            };
2699            let diff = diff.read(cx).snapshot(cx);
2700            let mut hunks = diff.hunks_in_row_range(0..u32::MAX, &buffer).peekable();
2701            self.expanded_diff_hunks_by_buffer
2702                .entry(buffer_id)
2703                .or_default()
2704                .retain(|hunk_anchor| {
2705                    if !hunk_anchor.is_valid(&buffer) {
2706                        return false;
2707                    }
2708                    while let Some(hunk) = hunks.peek() {
2709                        match hunk.buffer_range.start.cmp(hunk_anchor, &buffer) {
2710                            cmp::Ordering::Less => {
2711                                hunks.next();
2712                            }
2713                            cmp::Ordering::Equal => {
2714                                let hunk_range = hunk.buffer_range.to_offset(&buffer);
2715                                return hunk_range.end >= excerpt_range.start
2716                                    && hunk_range.start <= excerpt_range.end;
2717                            }
2718                            cmp::Ordering::Greater => break,
2719                        }
2720                    }
2721                    false
2722                });
2723        }
2724    }
2725
2726    fn add_diff(&mut self, diff: Entity<BufferDiff>, cx: &mut App) {
2727        let buffer_id = diff.read(cx).buffer_id;
2728        self.diffs.insert(buffer_id, diff);
2729    }
2730
2731    fn add_inverted_diff(
2732        &mut self,
2733        diff: Entity<BufferDiff>,
2734        main_buffer: Entity<language::Buffer>,
2735        cx: &App,
2736    ) {
2737        let base_text_buffer_id = diff.read(cx).base_text(cx).remote_id();
2738        self.inverted_diffs
2739            .insert(base_text_buffer_id, (diff, main_buffer));
2740    }
2741}
2742
2743#[gpui::test(iterations = 100)]
2744async fn test_random_set_ranges(cx: &mut TestAppContext, mut rng: StdRng) {
2745    let base_text = "a\n".repeat(100);
2746    let buf = cx.update(|cx| cx.new(|cx| Buffer::local(base_text, cx)));
2747    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
2748
2749    let operations = env::var("OPERATIONS")
2750        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2751        .unwrap_or(10);
2752
2753    fn row_ranges(ranges: &Vec<Range<Point>>) -> Vec<Range<u32>> {
2754        ranges
2755            .iter()
2756            .map(|range| range.start.row..range.end.row)
2757            .collect()
2758    }
2759
2760    for _ in 0..operations {
2761        let snapshot = buf.update(cx, |buf, _| buf.snapshot());
2762        let num_ranges = rng.random_range(0..=10);
2763        let max_row = snapshot.max_point().row;
2764        let mut ranges = (0..num_ranges)
2765            .map(|_| {
2766                let start = rng.random_range(0..max_row);
2767                let end = rng.random_range(start + 1..max_row + 1);
2768                Point::row_range(start..end)
2769            })
2770            .collect::<Vec<_>>();
2771        ranges.sort_by_key(|range| range.start);
2772        log::info!("Setting ranges: {:?}", row_ranges(&ranges));
2773        let (created, _) = multibuffer.update(cx, |multibuffer, cx| {
2774            multibuffer.set_excerpts_for_path(
2775                PathKey::for_buffer(&buf, cx),
2776                buf.clone(),
2777                ranges.clone(),
2778                2,
2779                cx,
2780            )
2781        });
2782
2783        assert_eq!(created.len(), ranges.len());
2784
2785        let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2786        let mut last_end = None;
2787        let mut seen_ranges = Vec::default();
2788
2789        for (buf, info) in snapshot.excerpts() {
2790            let start = info.range.start.to_point(buf);
2791            let end = info.range.end.to_point(buf);
2792            seen_ranges.push(start..end);
2793
2794            if let Some(last_end) = last_end.take() {
2795                assert!(
2796                    start > last_end,
2797                    "multibuffer has out-of-order ranges: {:?}; {:?} <= {:?}",
2798                    row_ranges(&seen_ranges),
2799                    start,
2800                    last_end
2801                )
2802            }
2803
2804            ranges.retain(|range| range.start < start || range.end > end);
2805
2806            last_end = Some(end)
2807        }
2808
2809        assert!(
2810            ranges.is_empty(),
2811            "multibuffer {:?} did not include all ranges: {:?}",
2812            row_ranges(&seen_ranges),
2813            row_ranges(&ranges)
2814        );
2815    }
2816}
2817
2818#[gpui::test(iterations = 100)]
2819async fn test_random_multibuffer(cx: &mut TestAppContext, mut rng: StdRng) {
2820    let operations = env::var("OPERATIONS")
2821        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2822        .unwrap_or(10);
2823    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
2824    let mut buffers: Vec<Entity<Buffer>> = Vec::new();
2825    let mut base_texts: HashMap<BufferId, String> = HashMap::default();
2826    let mut reference = ReferenceMultibuffer::default();
2827    let mut anchors = Vec::new();
2828    let mut old_versions = Vec::new();
2829    let mut needs_diff_calculation = false;
2830    let mut inverted_diff_main_buffers: HashMap<BufferId, Entity<BufferDiff>> = HashMap::default();
2831    for _ in 0..operations {
2832        match rng.random_range(0..100) {
2833            0..=14 if !buffers.is_empty() => {
2834                let buffer = buffers.choose(&mut rng).unwrap();
2835                buffer.update(cx, |buf, cx| {
2836                    let edit_count = rng.random_range(1..5);
2837                    buf.randomly_edit(&mut rng, edit_count, cx);
2838                    log::info!("buffer text:\n{}", buf.text());
2839                    needs_diff_calculation = true;
2840                });
2841                cx.update(|cx| reference.diffs_updated(cx));
2842            }
2843            15..=24 if !reference.excerpts.is_empty() => {
2844                multibuffer.update(cx, |multibuffer, cx| {
2845                    let snapshot = multibuffer.snapshot(cx);
2846                    let infos = snapshot
2847                        .excerpts()
2848                        .map(|(_, info)| info)
2849                        .collect::<Vec<_>>();
2850                    let mut excerpts = HashSet::default();
2851                    for _ in 0..rng.random_range(0..infos.len()) {
2852                        excerpts.extend(infos.choose(&mut rng).cloned());
2853                    }
2854
2855                    let line_count = rng.random_range(0..5);
2856
2857                    let excerpt_ixs = excerpts
2858                        .iter()
2859                        .map(|info| {
2860                            reference
2861                                .excerpts
2862                                .iter()
2863                                .position(|e| e.info(cx) == *info)
2864                                .unwrap()
2865                        })
2866                        .collect::<Vec<_>>();
2867                    log::info!("Expanding excerpts {excerpt_ixs:?} by {line_count} lines");
2868                    multibuffer.expand_excerpts(
2869                        excerpts
2870                            .iter()
2871                            .map(|info| Anchor::in_buffer(info.path_key_index, info.range.end)),
2872                        line_count,
2873                        ExpandExcerptDirection::UpAndDown,
2874                        cx,
2875                    );
2876
2877                    reference.expand_excerpts(&excerpts, line_count, cx);
2878                });
2879            }
2880            25..=34 if !reference.excerpts.is_empty() => {
2881                let multibuffer =
2882                    multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2883                let offset = multibuffer.clip_offset(
2884                    MultiBufferOffset(rng.random_range(0..=multibuffer.len().0)),
2885                    Bias::Left,
2886                );
2887                let bias = if rng.random() {
2888                    Bias::Left
2889                } else {
2890                    Bias::Right
2891                };
2892                log::info!("Creating anchor at {} with bias {:?}", offset.0, bias);
2893                anchors.push(multibuffer.anchor_at(offset, bias));
2894                anchors.sort_by(|a, b| a.cmp(b, &multibuffer));
2895            }
2896            35..=45 if !reference.excerpts.is_empty() => {
2897                multibuffer.update(cx, |multibuffer, cx| {
2898                    let snapshot = multibuffer.snapshot(cx);
2899                    let excerpt_ix = rng.random_range(0..reference.excerpts.len());
2900                    let excerpt = &reference.excerpts[excerpt_ix];
2901
2902                    // Skip inverted excerpts - hunks can't be collapsed
2903                    let buffer_id = excerpt.buffer.read(cx).remote_id();
2904                    if reference.inverted_diffs.contains_key(&buffer_id) {
2905                        return;
2906                    }
2907
2908                    let start = excerpt.range.start;
2909                    let end = excerpt.range.end;
2910                    let range = snapshot.anchor_in_buffer(excerpt.info(cx).buffer_id, start).unwrap()
2911                        ..snapshot.anchor_in_buffer(excerpt.info(cx).buffer_id, end).unwrap();
2912
2913                    log::info!(
2914                        "expanding diff hunks in range {:?} (excerpt index {excerpt_ix:?}, buffer id {:?})",
2915                        range.to_offset(&snapshot),
2916                        buffer_id,
2917                    );
2918                    reference.expand_diff_hunks(excerpt.path_key.clone(), start..end, cx);
2919                    multibuffer.expand_diff_hunks(vec![range], cx);
2920                });
2921            }
2922            46..=75 if needs_diff_calculation => {
2923                multibuffer.update(cx, |multibuffer, cx| {
2924                    for buffer in multibuffer.all_buffers() {
2925                        let snapshot = buffer.read(cx).snapshot();
2926                        let buffer_id = snapshot.remote_id();
2927
2928                        if let Some(diff) = multibuffer.diff_for(buffer_id) {
2929                            diff.update(cx, |diff, cx| {
2930                                log::info!("recalculating diff for buffer {:?}", buffer_id,);
2931                                diff.recalculate_diff_sync(&snapshot.text, cx);
2932                            });
2933                        }
2934
2935                        if let Some(inverted_diff) = inverted_diff_main_buffers.get(&buffer_id) {
2936                            inverted_diff.update(cx, |diff, cx| {
2937                                log::info!(
2938                                    "recalculating inverted diff for main buffer {:?}",
2939                                    buffer_id,
2940                                );
2941                                diff.recalculate_diff_sync(&snapshot.text, cx);
2942                            });
2943                        }
2944                    }
2945                    reference.diffs_updated(cx);
2946                    needs_diff_calculation = false;
2947                });
2948            }
2949            _ => {
2950                // Decide if we're creating a new buffer or reusing an existing one
2951                let create_new_buffer = buffers.is_empty() || rng.random_bool(0.4);
2952
2953                let (excerpt_buffer, diff, inverted_main_buffer) = if create_new_buffer {
2954                    let create_inverted = rng.random_bool(0.3);
2955
2956                    if create_inverted {
2957                        let mut main_buffer_text = util::RandomCharIter::new(&mut rng)
2958                            .take(256)
2959                            .collect::<String>();
2960                        let main_buffer = cx.new(|cx| Buffer::local(main_buffer_text.clone(), cx));
2961                        text::LineEnding::normalize(&mut main_buffer_text);
2962                        let main_buffer_id =
2963                            main_buffer.read_with(cx, |buffer, _| buffer.remote_id());
2964                        base_texts.insert(main_buffer_id, main_buffer_text.clone());
2965                        buffers.push(main_buffer.clone());
2966
2967                        let diff = cx.new(|cx| {
2968                            BufferDiff::new_with_base_text(
2969                                &main_buffer_text,
2970                                &main_buffer.read(cx).text_snapshot(),
2971                                cx,
2972                            )
2973                        });
2974
2975                        let base_text_buffer =
2976                            diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
2977
2978                        // Track for recalculation when main buffer is edited
2979                        inverted_diff_main_buffers.insert(main_buffer_id, diff.clone());
2980
2981                        (base_text_buffer, diff, Some(main_buffer))
2982                    } else {
2983                        let mut base_text = util::RandomCharIter::new(&mut rng)
2984                            .take(256)
2985                            .collect::<String>();
2986
2987                        let buffer_handle = cx.new(|cx| Buffer::local(base_text.clone(), cx));
2988                        text::LineEnding::normalize(&mut base_text);
2989                        let buffer_id = buffer_handle.read_with(cx, |buffer, _| buffer.remote_id());
2990                        base_texts.insert(buffer_id, base_text.clone());
2991                        buffers.push(buffer_handle.clone());
2992
2993                        let diff = cx.new(|cx| {
2994                            BufferDiff::new_with_base_text(
2995                                &base_text,
2996                                &buffer_handle.read(cx).text_snapshot(),
2997                                cx,
2998                            )
2999                        });
3000
3001                        (buffer_handle, diff, None)
3002                    }
3003                } else {
3004                    // Reuse an existing buffer
3005                    let buffer_handle = buffers.choose(&mut rng).unwrap().clone();
3006                    let buffer_id = buffer_handle.read_with(cx, |buffer, _| buffer.remote_id());
3007
3008                    if let Some(diff) = inverted_diff_main_buffers.get(&buffer_id) {
3009                        let base_text_buffer =
3010                            diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3011                        (base_text_buffer, diff.clone(), Some(buffer_handle))
3012                    } else {
3013                        // Get existing diff or create new one for regular buffer
3014                        let diff = multibuffer
3015                            .read_with(cx, |mb, _| mb.diff_for(buffer_id))
3016                            .unwrap_or_else(|| {
3017                                let base_text = base_texts.get(&buffer_id).unwrap();
3018                                cx.new(|cx| {
3019                                    BufferDiff::new_with_base_text(
3020                                        base_text,
3021                                        &buffer_handle.read(cx).text_snapshot(),
3022                                        cx,
3023                                    )
3024                                })
3025                            });
3026                        (buffer_handle, diff, None)
3027                    }
3028                };
3029
3030                let excerpt_buffer_snapshot =
3031                    excerpt_buffer.read_with(cx, |excerpt_buffer, _| excerpt_buffer.snapshot());
3032                let mut ranges = reference
3033                    .excerpts
3034                    .iter()
3035                    .filter(|excerpt| excerpt.buffer == excerpt_buffer)
3036                    .map(|excerpt| excerpt.range.to_point(&excerpt_buffer_snapshot))
3037                    .collect::<Vec<_>>();
3038                mutate_excerpt_ranges(&mut rng, &mut ranges, &excerpt_buffer_snapshot, 1);
3039                let ranges = ranges
3040                    .iter()
3041                    .cloned()
3042                    .map(ExcerptRange::new)
3043                    .collect::<Vec<_>>();
3044                let path = cx.update(|cx| PathKey::for_buffer(&excerpt_buffer, cx));
3045
3046                let (_, path_key_index, _) = multibuffer.update(cx, |multibuffer, cx| {
3047                    multibuffer.set_excerpt_ranges_for_path(
3048                        path.clone(),
3049                        excerpt_buffer.clone(),
3050                        &excerpt_buffer_snapshot,
3051                        ranges.clone(),
3052                        cx,
3053                    )
3054                });
3055
3056                reference.set_excerpts(
3057                    path,
3058                    path_key_index,
3059                    excerpt_buffer.clone(),
3060                    &excerpt_buffer_snapshot,
3061                    ranges,
3062                );
3063
3064                let excerpt_buffer_id =
3065                    excerpt_buffer.read_with(cx, |buffer, _| buffer.remote_id());
3066                multibuffer.update(cx, |multibuffer, cx| {
3067                    if multibuffer.diff_for(excerpt_buffer_id).is_none() {
3068                        if let Some(main_buffer) = inverted_main_buffer {
3069                            reference.add_inverted_diff(diff.clone(), main_buffer.clone(), cx);
3070                            multibuffer.add_inverted_diff(diff, main_buffer, cx);
3071                        } else {
3072                            reference.add_diff(diff.clone(), cx);
3073                            multibuffer.add_diff(diff, cx);
3074                        }
3075                    }
3076                });
3077            }
3078        }
3079
3080        if rng.random_bool(0.3) {
3081            multibuffer.update(cx, |multibuffer, cx| {
3082                old_versions.push((multibuffer.snapshot(cx), multibuffer.subscribe()));
3083            })
3084        }
3085
3086        multibuffer.read_with(cx, |multibuffer, cx| {
3087            check_multibuffer(multibuffer, &reference, &anchors, cx, &mut rng);
3088        });
3089    }
3090    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
3091    for (old_snapshot, subscription) in old_versions {
3092        check_multibuffer_edits(&snapshot, &old_snapshot, subscription);
3093    }
3094}
3095
3096fn mutate_excerpt_ranges(
3097    rng: &mut StdRng,
3098    existing_ranges: &mut Vec<Range<Point>>,
3099    buffer: &BufferSnapshot,
3100    operations: u32,
3101) {
3102    let mut ranges_to_add = Vec::new();
3103
3104    for _ in 0..operations {
3105        // todo!() logging
3106        match rng.random_range(0..5) {
3107            0..=1 if !existing_ranges.is_empty() => {
3108                log::info!("Removing excerpt",);
3109                let index = rng.random_range(0..existing_ranges.len());
3110                existing_ranges.remove(index);
3111            }
3112            _ => {
3113                log::info!("Inserting excerpt",);
3114                let end_row = rng.random_range(0..=buffer.max_point().row);
3115                let start_row = rng.random_range(0..=end_row);
3116                ranges_to_add.push(Point::new(start_row, 0)..Point::new(end_row, 0));
3117            }
3118        }
3119    }
3120
3121    existing_ranges.extend(ranges_to_add);
3122    existing_ranges.sort_by(|l, r| l.start.cmp(&r.start));
3123}
3124
3125fn check_multibuffer(
3126    multibuffer: &MultiBuffer,
3127    reference: &ReferenceMultibuffer,
3128    anchors: &[Anchor],
3129    cx: &App,
3130    rng: &mut StdRng,
3131) {
3132    let snapshot = multibuffer.snapshot(cx);
3133    let actual_text = snapshot.text();
3134    let actual_boundary_rows = snapshot
3135        .excerpt_boundaries_in_range(MultiBufferOffset(0)..)
3136        .map(|b| b.row)
3137        .collect::<HashSet<_>>();
3138    let actual_row_infos = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
3139
3140    let (expected_text, expected_row_infos, expected_boundary_rows) =
3141        reference.expected_content(cx);
3142
3143    let has_diff = actual_row_infos
3144        .iter()
3145        .any(|info| info.diff_status.is_some())
3146        || expected_row_infos
3147            .iter()
3148            .any(|info| info.diff_status.is_some());
3149    let actual_diff = format_diff(
3150        &actual_text,
3151        &actual_row_infos,
3152        &actual_boundary_rows,
3153        Some(has_diff),
3154    );
3155    let expected_diff = format_diff(
3156        &expected_text,
3157        &expected_row_infos,
3158        &expected_boundary_rows,
3159        Some(has_diff),
3160    );
3161
3162    log::info!("Multibuffer content:\n{}", actual_diff);
3163    dbg!(
3164        snapshot
3165            .excerpts()
3166            .map(|(buffer_snapshot, excerpt)| {
3167                (
3168                    buffer_snapshot.remote_id(),
3169                    excerpt.range.to_point(&buffer_snapshot),
3170                )
3171            })
3172            .collect::<Vec<_>>()
3173    );
3174
3175    assert_eq!(
3176        actual_row_infos.len(),
3177        actual_text.split('\n').count(),
3178        "line count: {}",
3179        actual_text.split('\n').count()
3180    );
3181    pretty_assertions::assert_eq!(actual_diff, expected_diff);
3182    pretty_assertions::assert_eq!(actual_text, expected_text);
3183    pretty_assertions::assert_eq!(actual_row_infos, expected_row_infos);
3184
3185    for _ in 0..5 {
3186        let start_row = rng.random_range(0..=expected_row_infos.len());
3187        assert_eq!(
3188            snapshot
3189                .row_infos(MultiBufferRow(start_row as u32))
3190                .collect::<Vec<_>>(),
3191            &expected_row_infos[start_row..],
3192            "buffer_rows({})",
3193            start_row
3194        );
3195    }
3196    // dbg!(&expected_row_infos);
3197
3198    // dbg!(
3199    //     snapshot
3200    //         .excerpts()
3201    //         .map(|(buffer_snapshot, excerpt)| {
3202    //             (
3203    //                 buffer_snapshot.remote_id(),
3204    //                 excerpt.range.to_point(&buffer_snapshot),
3205    //             )
3206    //         })
3207    //         .collect::<Vec<_>>()
3208    // );
3209    // dbg!(&expected_row_infos);
3210    // dbg!(
3211    //     reference
3212    //         .excerpts
3213    //         .iter()
3214    //         .map(|excerpt| { excerpt.range.to_point(&excerpt.buffer.read(cx).snapshot()) })
3215    //         .collect::<Vec<_>>()
3216    // );
3217
3218    assert_eq!(
3219        snapshot.widest_line_number(),
3220        expected_row_infos
3221            .into_iter()
3222            .filter_map(|info| {
3223                // For inverted diffs, deleted rows are visible and should be counted.
3224                // Only filter out deleted rows that are NOT from inverted diffs.
3225                let is_inverted_diff = info
3226                    .buffer_id
3227                    .is_some_and(|id| reference.inverted_diffs.contains_key(&id));
3228                if info.diff_status.is_some_and(|status| status.is_deleted()) && !is_inverted_diff {
3229                    None
3230                } else {
3231                    info.buffer_row
3232                }
3233            })
3234            .max()
3235            .unwrap()
3236            + 1
3237    );
3238    // let reference_ranges = reference
3239    //     .excerpts
3240    //     .iter()
3241    //     .map(|excerpt| {
3242    //         (
3243    //             excerpt.info(cx),
3244    //             excerpt.range.to_offset(&excerpt.buffer.read(cx).snapshot()),
3245    //         )
3246    //     })
3247    //     .collect::<Vec<_>>();
3248    for i in 0..snapshot.len().0 {
3249        // todo!() this seems not useful
3250        let excerpt = snapshot
3251            .excerpt_containing(MultiBufferOffset(i)..MultiBufferOffset(i))
3252            .unwrap();
3253        let reference_range = reference
3254            .excerpts
3255            .iter()
3256            .find(|reference_excerpt| reference_excerpt.info(cx) == excerpt.excerpt.info())
3257            .map(|excerpt| excerpt.range.to_offset(&excerpt.buffer.read(cx).snapshot()))
3258            .expect("corresponding excerpt should exist in reference multibuffer");
3259        assert_eq!(
3260            excerpt.buffer_range(&snapshot).start.0..excerpt.buffer_range(&snapshot).end.0,
3261            reference_range
3262        );
3263    }
3264
3265    assert_consistent_line_numbers(&snapshot);
3266    assert_position_translation(&snapshot);
3267
3268    for (row, line) in expected_text.split('\n').enumerate() {
3269        assert_eq!(
3270            snapshot.line_len(MultiBufferRow(row as u32)),
3271            line.len() as u32,
3272            "line_len({}).",
3273            row
3274        );
3275    }
3276
3277    let text_rope = Rope::from(expected_text.as_str());
3278    for _ in 0..10 {
3279        let end_ix = text_rope.clip_offset(rng.random_range(0..=text_rope.len()), Bias::Right);
3280        let start_ix = text_rope.clip_offset(rng.random_range(0..=end_ix), Bias::Left);
3281
3282        let text_for_range = snapshot
3283            .text_for_range(MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix))
3284            .collect::<String>();
3285        assert_eq!(
3286            text_for_range,
3287            &expected_text[start_ix..end_ix],
3288            "incorrect text for range {:?}",
3289            start_ix..end_ix
3290        );
3291
3292        let expected_summary =
3293            MBTextSummary::from(TextSummary::from(&expected_text[start_ix..end_ix]));
3294        assert_eq!(
3295            snapshot.text_summary_for_range::<MBTextSummary, _>(
3296                MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix)
3297            ),
3298            expected_summary,
3299            "incorrect summary for range {:?}",
3300            start_ix..end_ix
3301        );
3302    }
3303
3304    // Anchor resolution
3305    let summaries = snapshot.summaries_for_anchors::<MultiBufferOffset, _>(anchors);
3306    assert_eq!(anchors.len(), summaries.len());
3307    for (anchor, resolved_offset) in anchors.iter().zip(summaries) {
3308        assert!(resolved_offset <= snapshot.len());
3309        assert_eq!(
3310            snapshot.summary_for_anchor::<MultiBufferOffset>(anchor),
3311            resolved_offset,
3312            "anchor: {:?}",
3313            anchor
3314        );
3315    }
3316
3317    for _ in 0..10 {
3318        let end_ix = text_rope.clip_offset(rng.random_range(0..=text_rope.len()), Bias::Right);
3319        assert_eq!(
3320            snapshot
3321                .reversed_chars_at(MultiBufferOffset(end_ix))
3322                .collect::<String>(),
3323            expected_text[..end_ix].chars().rev().collect::<String>(),
3324        );
3325    }
3326
3327    for _ in 0..10 {
3328        let end_ix = rng.random_range(0..=text_rope.len());
3329        let end_ix = text_rope.floor_char_boundary(end_ix);
3330        let start_ix = rng.random_range(0..=end_ix);
3331        let start_ix = text_rope.floor_char_boundary(start_ix);
3332        assert_eq!(
3333            snapshot
3334                .bytes_in_range(MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix))
3335                .flatten()
3336                .copied()
3337                .collect::<Vec<_>>(),
3338            expected_text.as_bytes()[start_ix..end_ix].to_vec(),
3339            "bytes_in_range({:?})",
3340            start_ix..end_ix,
3341        );
3342    }
3343}
3344
3345fn check_multibuffer_edits(
3346    snapshot: &MultiBufferSnapshot,
3347    old_snapshot: &MultiBufferSnapshot,
3348    subscription: Subscription<MultiBufferOffset>,
3349) {
3350    let edits = subscription.consume().into_inner();
3351
3352    log::info!(
3353        "applying subscription edits to old text: {:?}: {:#?}",
3354        old_snapshot.text(),
3355        edits,
3356    );
3357
3358    let mut text = old_snapshot.text();
3359    for edit in edits {
3360        let new_text: String = snapshot
3361            .text_for_range(edit.new.start..edit.new.end)
3362            .collect();
3363        text.replace_range(
3364            (edit.new.start.0..edit.new.start.0 + (edit.old.end.0 - edit.old.start.0)).clone(),
3365            &new_text,
3366        );
3367        pretty_assertions::assert_eq!(
3368            &text[0..edit.new.end.0],
3369            snapshot
3370                .text_for_range(MultiBufferOffset(0)..edit.new.end)
3371                .collect::<String>()
3372        );
3373    }
3374    pretty_assertions::assert_eq!(text, snapshot.text());
3375}
3376
3377#[gpui::test]
3378fn test_history(cx: &mut App) {
3379    let test_settings = SettingsStore::test(cx);
3380    cx.set_global(test_settings);
3381
3382    let group_interval: Duration = Duration::from_millis(1);
3383    let buffer_1 = cx.new(|cx| {
3384        let mut buf = Buffer::local("1234", cx);
3385        buf.set_group_interval(group_interval);
3386        buf
3387    });
3388    let buffer_2 = cx.new(|cx| {
3389        let mut buf = Buffer::local("5678", cx);
3390        buf.set_group_interval(group_interval);
3391        buf
3392    });
3393    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
3394    multibuffer.update(cx, |this, _| {
3395        this.set_group_interval(group_interval);
3396    });
3397    multibuffer.update(cx, |multibuffer, cx| {
3398        multibuffer.set_excerpts_for_path(
3399            PathKey::sorted(0),
3400            buffer_1.clone(),
3401            [Point::zero()..buffer_1.read(cx).max_point()],
3402            0,
3403            cx,
3404        );
3405        multibuffer.set_excerpts_for_path(
3406            PathKey::sorted(1),
3407            buffer_2.clone(),
3408            [Point::zero()..buffer_2.read(cx).max_point()],
3409            0,
3410            cx,
3411        );
3412    });
3413
3414    let mut now = Instant::now();
3415
3416    multibuffer.update(cx, |multibuffer, cx| {
3417        let transaction_1 = multibuffer.start_transaction_at(now, cx).unwrap();
3418        multibuffer.edit(
3419            [
3420                (Point::new(0, 0)..Point::new(0, 0), "A"),
3421                (Point::new(1, 0)..Point::new(1, 0), "A"),
3422            ],
3423            None,
3424            cx,
3425        );
3426        multibuffer.edit(
3427            [
3428                (Point::new(0, 1)..Point::new(0, 1), "B"),
3429                (Point::new(1, 1)..Point::new(1, 1), "B"),
3430            ],
3431            None,
3432            cx,
3433        );
3434        multibuffer.end_transaction_at(now, cx);
3435        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3436
3437        // Verify edited ranges for transaction 1
3438        assert_eq!(
3439            multibuffer.edited_ranges_for_transaction(transaction_1, cx),
3440            &[
3441                MultiBufferOffset(0)..MultiBufferOffset(2),
3442                MultiBufferOffset(7)..MultiBufferOffset(9),
3443            ]
3444        );
3445
3446        // Edit buffer 1 through the multibuffer
3447        now += 2 * group_interval;
3448        multibuffer.start_transaction_at(now, cx);
3449        multibuffer.edit(
3450            [(MultiBufferOffset(2)..MultiBufferOffset(2), "C")],
3451            None,
3452            cx,
3453        );
3454        multibuffer.end_transaction_at(now, cx);
3455        assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3456
3457        // Edit buffer 1 independently
3458        buffer_1.update(cx, |buffer_1, cx| {
3459            buffer_1.start_transaction_at(now);
3460            buffer_1.edit([(3..3, "D")], None, cx);
3461            buffer_1.end_transaction_at(now, cx);
3462
3463            now += 2 * group_interval;
3464            buffer_1.start_transaction_at(now);
3465            buffer_1.edit([(4..4, "E")], None, cx);
3466            buffer_1.end_transaction_at(now, cx);
3467        });
3468        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\nAB5678");
3469
3470        // An undo in the multibuffer undoes the multibuffer transaction
3471        // and also any individual buffer edits that have occurred since
3472        // that transaction.
3473        multibuffer.undo(cx);
3474        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3475
3476        multibuffer.undo(cx);
3477        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3478
3479        multibuffer.redo(cx);
3480        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3481
3482        multibuffer.redo(cx);
3483        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\nAB5678");
3484
3485        // Undo buffer 2 independently.
3486        buffer_2.update(cx, |buffer_2, cx| buffer_2.undo(cx));
3487        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\n5678");
3488
3489        // An undo in the multibuffer undoes the components of the
3490        // the last multibuffer transaction that are not already undone.
3491        multibuffer.undo(cx);
3492        assert_eq!(multibuffer.read(cx).text(), "AB1234\n5678");
3493
3494        multibuffer.undo(cx);
3495        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3496
3497        multibuffer.redo(cx);
3498        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3499
3500        buffer_1.update(cx, |buffer_1, cx| buffer_1.redo(cx));
3501        assert_eq!(multibuffer.read(cx).text(), "ABCD1234\nAB5678");
3502
3503        // Redo stack gets cleared after an edit.
3504        now += 2 * group_interval;
3505        multibuffer.start_transaction_at(now, cx);
3506        multibuffer.edit(
3507            [(MultiBufferOffset(0)..MultiBufferOffset(0), "X")],
3508            None,
3509            cx,
3510        );
3511        multibuffer.end_transaction_at(now, cx);
3512        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3513        multibuffer.redo(cx);
3514        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3515        multibuffer.undo(cx);
3516        assert_eq!(multibuffer.read(cx).text(), "ABCD1234\nAB5678");
3517        multibuffer.undo(cx);
3518        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3519
3520        // Transactions can be grouped manually.
3521        multibuffer.redo(cx);
3522        multibuffer.redo(cx);
3523        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3524        multibuffer.group_until_transaction(transaction_1, cx);
3525        multibuffer.undo(cx);
3526        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3527        multibuffer.redo(cx);
3528        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3529    });
3530}
3531
3532#[gpui::test]
3533async fn test_enclosing_indent(cx: &mut TestAppContext) {
3534    async fn enclosing_indent(
3535        text: &str,
3536        buffer_row: u32,
3537        cx: &mut TestAppContext,
3538    ) -> Option<(Range<u32>, LineIndent)> {
3539        let buffer = cx.update(|cx| MultiBuffer::build_simple(text, cx));
3540        let snapshot = cx.read(|cx| buffer.read(cx).snapshot(cx));
3541        let (range, indent) = snapshot
3542            .enclosing_indent(MultiBufferRow(buffer_row))
3543            .await?;
3544        Some((range.start.0..range.end.0, indent))
3545    }
3546
3547    assert_eq!(
3548        enclosing_indent(
3549            indoc!(
3550                "
3551                fn b() {
3552                    if c {
3553                        let d = 2;
3554                    }
3555                }
3556                "
3557            ),
3558            1,
3559            cx,
3560        )
3561        .await,
3562        Some((
3563            1..2,
3564            LineIndent {
3565                tabs: 0,
3566                spaces: 4,
3567                line_blank: false,
3568            }
3569        ))
3570    );
3571
3572    assert_eq!(
3573        enclosing_indent(
3574            indoc!(
3575                "
3576                fn b() {
3577                    if c {
3578                        let d = 2;
3579                    }
3580                }
3581                "
3582            ),
3583            2,
3584            cx,
3585        )
3586        .await,
3587        Some((
3588            1..2,
3589            LineIndent {
3590                tabs: 0,
3591                spaces: 4,
3592                line_blank: false,
3593            }
3594        ))
3595    );
3596
3597    assert_eq!(
3598        enclosing_indent(
3599            indoc!(
3600                "
3601                fn b() {
3602                    if c {
3603                        let d = 2;
3604
3605                        let e = 5;
3606                    }
3607                }
3608                "
3609            ),
3610            3,
3611            cx,
3612        )
3613        .await,
3614        Some((
3615            1..4,
3616            LineIndent {
3617                tabs: 0,
3618                spaces: 4,
3619                line_blank: false,
3620            }
3621        ))
3622    );
3623}
3624
3625#[gpui::test]
3626async fn test_summaries_for_anchors(cx: &mut TestAppContext) {
3627    let base_text_1 = indoc!(
3628        "
3629        bar
3630        "
3631    );
3632    let text_1 = indoc!(
3633        "
3634        BAR
3635        "
3636    );
3637    let base_text_2 = indoc!(
3638        "
3639        foo
3640        "
3641    );
3642    let text_2 = indoc!(
3643        "
3644        FOO
3645        "
3646    );
3647
3648    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
3649    let buffer_2 = cx.new(|cx| Buffer::local(text_2, cx));
3650    let diff_1 = cx.new(|cx| {
3651        BufferDiff::new_with_base_text(base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
3652    });
3653    let diff_2 = cx.new(|cx| {
3654        BufferDiff::new_with_base_text(base_text_2, &buffer_2.read(cx).text_snapshot(), cx)
3655    });
3656    cx.run_until_parked();
3657
3658    let multibuffer = cx.new(|cx| {
3659        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3660        multibuffer.set_all_diff_hunks_expanded(cx);
3661        multibuffer.set_excerpts_for_path(
3662            PathKey::sorted(0),
3663            buffer_1.clone(),
3664            [Point::zero()..buffer_1.read(cx).max_point()],
3665            0,
3666            cx,
3667        );
3668        multibuffer.set_excerpts_for_path(
3669            PathKey::sorted(1),
3670            buffer_2.clone(),
3671            [Point::zero()..buffer_2.read(cx).max_point()],
3672            0,
3673            cx,
3674        );
3675        multibuffer.add_diff(diff_1.clone(), cx);
3676        multibuffer.add_diff(diff_2.clone(), cx);
3677        multibuffer
3678    });
3679
3680    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3681        (multibuffer.snapshot(cx), multibuffer.subscribe())
3682    });
3683
3684    assert_new_snapshot(
3685        &multibuffer,
3686        &mut snapshot,
3687        &mut subscription,
3688        cx,
3689        indoc!(
3690            "
3691            - bar
3692            + BAR
3693
3694            - foo
3695            + FOO
3696            "
3697        ),
3698    );
3699
3700    let anchor_1 = multibuffer.read_with(cx, |multibuffer, cx| {
3701        multibuffer
3702            .buffer_anchor_to_anchor(
3703                &buffer_1,
3704                text::Anchor::min_for_buffer(buffer_1.read(cx).remote_id()),
3705                cx,
3706            )
3707            .unwrap()
3708    });
3709    let point_1 = snapshot.summaries_for_anchors::<Point, _>([&anchor_1])[0];
3710    assert_eq!(point_1, Point::new(0, 0));
3711
3712    let anchor_2 = multibuffer.read_with(cx, |multibuffer, cx| {
3713        multibuffer
3714            .buffer_anchor_to_anchor(
3715                &buffer_2,
3716                text::Anchor::min_for_buffer(buffer_2.read(cx).remote_id()),
3717                cx,
3718            )
3719            .unwrap()
3720    });
3721    let point_2 = snapshot.summaries_for_anchors::<Point, _>([&anchor_2])[0];
3722    assert_eq!(point_2, Point::new(3, 0));
3723}
3724
3725#[gpui::test]
3726async fn test_trailing_deletion_without_newline(cx: &mut TestAppContext) {
3727    let base_text_1 = "one\ntwo".to_owned();
3728    let text_1 = "one\n".to_owned();
3729
3730    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
3731    let diff_1 = cx.new(|cx| {
3732        BufferDiff::new_with_base_text(&base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
3733    });
3734    cx.run_until_parked();
3735
3736    let multibuffer = cx.new(|cx| {
3737        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3738        multibuffer.set_excerpts_for_path(
3739            PathKey::sorted(0),
3740            buffer_1.clone(),
3741            [Point::zero()..buffer_1.read(cx).max_point()],
3742            0,
3743            cx,
3744        );
3745        multibuffer.add_diff(diff_1.clone(), cx);
3746        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
3747        multibuffer
3748    });
3749
3750    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3751        (multibuffer.snapshot(cx), multibuffer.subscribe())
3752    });
3753
3754    assert_new_snapshot(
3755        &multibuffer,
3756        &mut snapshot,
3757        &mut subscription,
3758        cx,
3759        indoc!(
3760            "
3761              one
3762            - two
3763            "
3764        ),
3765    );
3766
3767    assert_eq!(snapshot.max_point(), Point::new(2, 0));
3768    assert_eq!(snapshot.len().0, 8);
3769
3770    assert_eq!(
3771        snapshot
3772            .dimensions_from_points::<Point>([Point::new(2, 0)])
3773            .collect::<Vec<_>>(),
3774        vec![Point::new(2, 0)]
3775    );
3776
3777    let (_, translated_offset) = snapshot.point_to_buffer_offset(Point::new(2, 0)).unwrap();
3778    assert_eq!(translated_offset.0, "one\n".len());
3779    let (_, translated_point) = snapshot.point_to_buffer_point(Point::new(2, 0)).unwrap();
3780    assert_eq!(translated_point, Point::new(1, 0));
3781
3782    // The same, for an excerpt that's not at the end of the multibuffer.
3783
3784    let text_2 = "foo\n".to_owned();
3785    let buffer_2 = cx.new(|cx| Buffer::local(&text_2, cx));
3786    multibuffer.update(cx, |multibuffer, cx| {
3787        multibuffer.set_excerpt_ranges_for_path(
3788            PathKey::sorted(1),
3789            buffer_2.clone(),
3790            &buffer_2.read(cx).snapshot(),
3791            vec![ExcerptRange::new(Point::new(0, 0)..Point::new(1, 0))],
3792            cx,
3793        );
3794    });
3795
3796    assert_new_snapshot(
3797        &multibuffer,
3798        &mut snapshot,
3799        &mut subscription,
3800        cx,
3801        indoc!(
3802            "
3803              one
3804            - two
3805
3806              foo
3807            "
3808        ),
3809    );
3810
3811    assert_eq!(
3812        snapshot
3813            .dimensions_from_points::<Point>([Point::new(2, 0)])
3814            .collect::<Vec<_>>(),
3815        vec![Point::new(2, 0)]
3816    );
3817
3818    let buffer_1_id = buffer_1.read_with(cx, |buffer_1, _| buffer_1.remote_id());
3819    let (buffer, translated_offset) = snapshot.point_to_buffer_offset(Point::new(2, 0)).unwrap();
3820    assert_eq!(buffer.remote_id(), buffer_1_id);
3821    assert_eq!(translated_offset.0, "one\n".len());
3822    let (buffer, translated_point) = snapshot.point_to_buffer_point(Point::new(2, 0)).unwrap();
3823    assert_eq!(buffer.remote_id(), buffer_1_id);
3824    assert_eq!(translated_point, Point::new(1, 0));
3825}
3826
3827fn format_diff(
3828    text: &str,
3829    row_infos: &Vec<RowInfo>,
3830    boundary_rows: &HashSet<MultiBufferRow>,
3831    has_diff: Option<bool>,
3832) -> String {
3833    let has_diff =
3834        has_diff.unwrap_or_else(|| row_infos.iter().any(|info| info.diff_status.is_some()));
3835    text.split('\n')
3836        .enumerate()
3837        .zip(row_infos)
3838        .map(|((ix, line), info)| {
3839            let marker = match info.diff_status.map(|status| status.kind) {
3840                Some(DiffHunkStatusKind::Added) => "+ ",
3841                Some(DiffHunkStatusKind::Deleted) => "- ",
3842                Some(DiffHunkStatusKind::Modified) => unreachable!(),
3843                None => {
3844                    if has_diff && !line.is_empty() {
3845                        "  "
3846                    } else {
3847                        ""
3848                    }
3849                }
3850            };
3851            let boundary_row = if boundary_rows.contains(&MultiBufferRow(ix as u32)) {
3852                if has_diff {
3853                    "  ----------\n"
3854                } else {
3855                    "---------\n"
3856                }
3857            } else {
3858                ""
3859            };
3860            let expand = info
3861                .expand_info
3862                .as_ref()
3863                .map(|expand_info| match expand_info.direction {
3864                    ExpandExcerptDirection::Up => " [↑]",
3865                    ExpandExcerptDirection::Down => " [↓]",
3866                    ExpandExcerptDirection::UpAndDown => " [↕]",
3867                })
3868                .unwrap_or_default();
3869
3870            format!("{boundary_row}{marker}{line}{expand}")
3871            // let mbr = info
3872            //     .multibuffer_row
3873            //     .map(|row| format!("{:0>3}", row.0))
3874            //     .unwrap_or_else(|| "???".to_string());
3875            // let byte_range = format!("{byte_range_start:0>3}..{byte_range_end:0>3}");
3876            // format!("{boundary_row}Row: {mbr}, Bytes: {byte_range} | {marker}{line}{expand}")
3877        })
3878        .collect::<Vec<_>>()
3879        .join("\n")
3880}
3881
3882// fn format_transforms(snapshot: &MultiBufferSnapshot) -> String {
3883//     snapshot
3884//         .diff_transforms
3885//         .iter()
3886//         .map(|transform| {
3887//             let (kind, summary) = match transform {
3888//                 DiffTransform::DeletedHunk { summary, .. } => ("   Deleted", (*summary).into()),
3889//                 DiffTransform::FilteredInsertedHunk { summary, .. } => ("  Filtered", *summary),
3890//                 DiffTransform::InsertedHunk { summary, .. } => ("  Inserted", *summary),
3891//                 DiffTransform::Unmodified { summary, .. } => ("Unmodified", *summary),
3892//             };
3893//             format!("{kind}(len: {}, lines: {:?})", summary.len, summary.lines)
3894//         })
3895//         .join("\n")
3896// }
3897
3898// fn format_excerpts(snapshot: &MultiBufferSnapshot) -> String {
3899//     snapshot
3900//         .excerpts
3901//         .iter()
3902//         .map(|excerpt| {
3903//             format!(
3904//                 "Excerpt(buffer_range = {:?}, lines = {:?}, has_trailing_newline = {:?})",
3905//                 excerpt.range.context.to_point(&excerpt.buffer),
3906//                 excerpt.text_summary.lines,
3907//                 excerpt.has_trailing_newline
3908//             )
3909//         })
3910//         .join("\n")
3911// }
3912
3913#[gpui::test]
3914async fn test_singleton_with_inverted_diff(cx: &mut TestAppContext) {
3915    let text = indoc!(
3916        "
3917        ZERO
3918        one
3919        TWO
3920        three
3921        six
3922        "
3923    );
3924    let base_text = indoc!(
3925        "
3926        one
3927        two
3928        three
3929        four
3930        five
3931        six
3932        "
3933    );
3934
3935    let buffer = cx.new(|cx| Buffer::local(text, cx));
3936    let diff = cx
3937        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
3938    cx.run_until_parked();
3939
3940    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3941
3942    let multibuffer = cx.new(|cx| {
3943        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
3944        multibuffer.set_all_diff_hunks_expanded(cx);
3945        multibuffer.add_inverted_diff(diff.clone(), buffer.clone(), cx);
3946        multibuffer
3947    });
3948
3949    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3950        (multibuffer.snapshot(cx), multibuffer.subscribe())
3951    });
3952
3953    assert_eq!(snapshot.text(), base_text);
3954    assert_new_snapshot(
3955        &multibuffer,
3956        &mut snapshot,
3957        &mut subscription,
3958        cx,
3959        indoc!(
3960            "
3961              one
3962            - two
3963              three
3964            - four
3965            - five
3966              six
3967            "
3968        ),
3969    );
3970
3971    buffer.update(cx, |buffer, cx| {
3972        buffer.edit_via_marked_text(
3973            indoc!(
3974                "
3975                ZERO
3976                one
3977                «<inserted>»W«O
3978                T»hree
3979                six
3980                "
3981            ),
3982            None,
3983            cx,
3984        );
3985    });
3986    cx.run_until_parked();
3987    let update = diff
3988        .update(cx, |diff, cx| {
3989            diff.update_diff(
3990                buffer.read(cx).text_snapshot(),
3991                Some(base_text.into()),
3992                None,
3993                None,
3994                cx,
3995            )
3996        })
3997        .await;
3998    diff.update(cx, |diff, cx| {
3999        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4000    })
4001    .await;
4002    cx.run_until_parked();
4003
4004    assert_new_snapshot(
4005        &multibuffer,
4006        &mut snapshot,
4007        &mut subscription,
4008        cx,
4009        indoc! {
4010            "
4011              one
4012            - two
4013            - three
4014            - four
4015            - five
4016              six
4017            "
4018        },
4019    );
4020
4021    buffer.update(cx, |buffer, cx| {
4022        buffer.set_text("ZERO\nONE\nTWO\n", cx);
4023    });
4024    cx.run_until_parked();
4025    let update = diff
4026        .update(cx, |diff, cx| {
4027            diff.update_diff(
4028                buffer.read(cx).text_snapshot(),
4029                Some(base_text.into()),
4030                None,
4031                None,
4032                cx,
4033            )
4034        })
4035        .await;
4036    diff.update(cx, |diff, cx| {
4037        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4038    })
4039    .await;
4040    cx.run_until_parked();
4041
4042    assert_new_snapshot(
4043        &multibuffer,
4044        &mut snapshot,
4045        &mut subscription,
4046        cx,
4047        indoc! {
4048            "
4049            - one
4050            - two
4051            - three
4052            - four
4053            - five
4054            - six
4055            "
4056        },
4057    );
4058
4059    diff.update(cx, |diff, cx| {
4060        diff.set_base_text(
4061            Some("new base\n".into()),
4062            None,
4063            buffer.read(cx).text_snapshot(),
4064            cx,
4065        )
4066    })
4067    .await
4068    .unwrap();
4069    cx.run_until_parked();
4070
4071    assert_new_snapshot(
4072        &multibuffer,
4073        &mut snapshot,
4074        &mut subscription,
4075        cx,
4076        indoc! {"
4077            - new base
4078        "},
4079    );
4080}
4081
4082#[gpui::test]
4083async fn test_inverted_diff_base_text_change(cx: &mut TestAppContext) {
4084    let base_text = "aaa\nbbb\nccc\n";
4085    let text = "ddd\n";
4086    let buffer = cx.new(|cx| Buffer::local(text, cx));
4087    let diff = cx
4088        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
4089    cx.run_until_parked();
4090
4091    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
4092
4093    let multibuffer = cx.new(|cx| {
4094        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
4095        multibuffer.set_all_diff_hunks_expanded(cx);
4096        multibuffer.add_inverted_diff(diff.clone(), buffer.clone(), cx);
4097        multibuffer
4098    });
4099
4100    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
4101        (multibuffer.snapshot(cx), multibuffer.subscribe())
4102    });
4103
4104    assert_eq!(snapshot.text(), base_text);
4105    assert_new_snapshot(
4106        &multibuffer,
4107        &mut snapshot,
4108        &mut subscription,
4109        cx,
4110        indoc!(
4111            "
4112            - aaa
4113            - bbb
4114            - ccc
4115            "
4116        ),
4117    );
4118
4119    let update = diff
4120        .update(cx, |diff, cx| {
4121            diff.update_diff(
4122                buffer.read(cx).text_snapshot(),
4123                Some("ddd\n".into()),
4124                Some(true),
4125                None,
4126                cx,
4127            )
4128        })
4129        .await;
4130    diff.update(cx, |diff, cx| {
4131        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4132    })
4133    .detach();
4134
4135    let _hunks: Vec<_> = multibuffer
4136        .read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx))
4137        .diff_hunks()
4138        .collect();
4139}
4140
4141#[gpui::test]
4142async fn test_inverted_diff_secondary_version_mismatch(cx: &mut TestAppContext) {
4143    let base_text = "one\ntwo\nthree\nfour\nfive\n";
4144    let index_text = "one\nTWO\nthree\nfour\nfive\n";
4145    let buffer_text = "one\nTWO\nthree\nFOUR\nfive\n";
4146
4147    let buffer = cx.new(|cx| Buffer::local(buffer_text, cx));
4148
4149    let unstaged_diff = cx
4150        .new(|cx| BufferDiff::new_with_base_text(index_text, &buffer.read(cx).text_snapshot(), cx));
4151    cx.run_until_parked();
4152
4153    let uncommitted_diff = cx.new(|cx| {
4154        let mut diff =
4155            BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx);
4156        diff.set_secondary_diff(unstaged_diff.clone());
4157        diff
4158    });
4159    cx.run_until_parked();
4160
4161    buffer.update(cx, |buffer, cx| {
4162        buffer.edit([(0..0, "ZERO\n")], None, cx);
4163    });
4164
4165    let update = unstaged_diff
4166        .update(cx, |diff, cx| {
4167            diff.update_diff(
4168                buffer.read(cx).text_snapshot(),
4169                Some(index_text.into()),
4170                None,
4171                None,
4172                cx,
4173            )
4174        })
4175        .await;
4176    unstaged_diff
4177        .update(cx, |diff, cx| {
4178            diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4179        })
4180        .await;
4181
4182    let base_text_buffer =
4183        uncommitted_diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
4184
4185    let multibuffer = cx.new(|cx| {
4186        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
4187        multibuffer.set_all_diff_hunks_expanded(cx);
4188        multibuffer.add_inverted_diff(uncommitted_diff.clone(), buffer.clone(), cx);
4189        multibuffer
4190    });
4191
4192    let _hunks: Vec<_> = multibuffer
4193        .read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx))
4194        .diff_hunks()
4195        .collect();
4196}
4197
4198#[track_caller]
4199fn assert_excerpts_match(
4200    multibuffer: &Entity<MultiBuffer>,
4201    cx: &mut TestAppContext,
4202    expected: &str,
4203) {
4204    let mut output = String::new();
4205    multibuffer.read_with(cx, |multibuffer, cx| {
4206        for (buffer, info) in multibuffer.snapshot(cx).excerpts() {
4207            output.push_str("-----\n");
4208            output.extend(buffer.text_for_range(info.range));
4209            if !output.ends_with('\n') {
4210                output.push('\n');
4211            }
4212        }
4213    });
4214    assert_eq!(output, expected);
4215}
4216
4217#[track_caller]
4218fn assert_new_snapshot(
4219    multibuffer: &Entity<MultiBuffer>,
4220    snapshot: &mut MultiBufferSnapshot,
4221    subscription: &mut Subscription<MultiBufferOffset>,
4222    cx: &mut TestAppContext,
4223    expected_diff: &str,
4224) {
4225    let new_snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
4226    let actual_text = new_snapshot.text();
4227    let line_infos = new_snapshot
4228        .row_infos(MultiBufferRow(0))
4229        .collect::<Vec<_>>();
4230    let actual_diff = format_diff(&actual_text, &line_infos, &Default::default(), None);
4231    pretty_assertions::assert_eq!(actual_diff, expected_diff);
4232    check_edits(
4233        snapshot,
4234        &new_snapshot,
4235        &subscription.consume().into_inner(),
4236    );
4237    *snapshot = new_snapshot;
4238}
4239
4240#[track_caller]
4241fn check_edits(
4242    old_snapshot: &MultiBufferSnapshot,
4243    new_snapshot: &MultiBufferSnapshot,
4244    edits: &[Edit<MultiBufferOffset>],
4245) {
4246    let mut text = old_snapshot.text();
4247    let new_text = new_snapshot.text();
4248    for edit in edits.iter().rev() {
4249        if !text.is_char_boundary(edit.old.start.0)
4250            || !text.is_char_boundary(edit.old.end.0)
4251            || !new_text.is_char_boundary(edit.new.start.0)
4252            || !new_text.is_char_boundary(edit.new.end.0)
4253        {
4254            panic!(
4255                "invalid edits: {:?}\nold text: {:?}\nnew text: {:?}",
4256                edits, text, new_text
4257            );
4258        }
4259
4260        text.replace_range(
4261            edit.old.start.0..edit.old.end.0,
4262            &new_text[edit.new.start.0..edit.new.end.0],
4263        );
4264    }
4265
4266    pretty_assertions::assert_eq!(text, new_text, "invalid edits: {:?}", edits);
4267}
4268
4269#[track_caller]
4270fn assert_chunks_in_ranges(snapshot: &MultiBufferSnapshot) {
4271    let full_text = snapshot.text();
4272    for ix in 0..full_text.len() {
4273        let mut chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4274        chunks.seek(MultiBufferOffset(ix)..snapshot.len());
4275        let tail = chunks.map(|chunk| chunk.text).collect::<String>();
4276        assert_eq!(tail, &full_text[ix..], "seek to range: {:?}", ix..);
4277    }
4278}
4279
4280#[track_caller]
4281fn assert_consistent_line_numbers(snapshot: &MultiBufferSnapshot) {
4282    let all_line_numbers = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
4283    for start_row in 1..all_line_numbers.len() {
4284        let line_numbers = snapshot
4285            .row_infos(MultiBufferRow(start_row as u32))
4286            .collect::<Vec<_>>();
4287        assert_eq!(
4288            line_numbers,
4289            all_line_numbers[start_row..],
4290            "start_row: {start_row}"
4291        );
4292    }
4293}
4294
4295#[track_caller]
4296fn assert_position_translation(snapshot: &MultiBufferSnapshot) {
4297    let text = Rope::from(snapshot.text());
4298
4299    let mut left_anchors = Vec::new();
4300    let mut right_anchors = Vec::new();
4301    let mut offsets = Vec::new();
4302    let mut points = Vec::new();
4303    for offset in 0..=text.len() + 1 {
4304        let offset = MultiBufferOffset(offset);
4305        let clipped_left = snapshot.clip_offset(offset, Bias::Left);
4306        let clipped_right = snapshot.clip_offset(offset, Bias::Right);
4307        assert_eq!(
4308            clipped_left.0,
4309            text.clip_offset(offset.0, Bias::Left),
4310            "clip_offset({offset:?}, Left)"
4311        );
4312        assert_eq!(
4313            clipped_right.0,
4314            text.clip_offset(offset.0, Bias::Right),
4315            "clip_offset({offset:?}, Right)"
4316        );
4317        assert_eq!(
4318            snapshot.offset_to_point(clipped_left),
4319            text.offset_to_point(clipped_left.0),
4320            "offset_to_point({})",
4321            clipped_left.0
4322        );
4323        assert_eq!(
4324            snapshot.offset_to_point(clipped_right),
4325            text.offset_to_point(clipped_right.0),
4326            "offset_to_point({})",
4327            clipped_right.0
4328        );
4329        let anchor_after = snapshot.anchor_after(clipped_left);
4330        assert_eq!(
4331            anchor_after.to_offset(snapshot),
4332            clipped_left,
4333            "anchor_after({}).to_offset {anchor_after:?}",
4334            clipped_left.0
4335        );
4336        let anchor_before = snapshot.anchor_before(clipped_left);
4337        assert_eq!(
4338            anchor_before.to_offset(snapshot),
4339            clipped_left,
4340            "anchor_before({}).to_offset",
4341            clipped_left.0
4342        );
4343        left_anchors.push(anchor_before);
4344        right_anchors.push(anchor_after);
4345        offsets.push(clipped_left);
4346        points.push(text.offset_to_point(clipped_left.0));
4347    }
4348
4349    for row in 0..text.max_point().row {
4350        for column in 0..text.line_len(row) + 1 {
4351            let point = Point { row, column };
4352            let clipped_left = snapshot.clip_point(point, Bias::Left);
4353            let clipped_right = snapshot.clip_point(point, Bias::Right);
4354            assert_eq!(
4355                clipped_left,
4356                text.clip_point(point, Bias::Left),
4357                "clip_point({point:?}, Left)"
4358            );
4359            assert_eq!(
4360                clipped_right,
4361                text.clip_point(point, Bias::Right),
4362                "clip_point({point:?}, Right)"
4363            );
4364            assert_eq!(
4365                snapshot.point_to_offset(clipped_left).0,
4366                text.point_to_offset(clipped_left),
4367                "point_to_offset({clipped_left:?})"
4368            );
4369            assert_eq!(
4370                snapshot.point_to_offset(clipped_right).0,
4371                text.point_to_offset(clipped_right),
4372                "point_to_offset({clipped_right:?})"
4373            );
4374        }
4375    }
4376
4377    assert_eq!(
4378        snapshot.summaries_for_anchors::<MultiBufferOffset, _>(&left_anchors),
4379        offsets,
4380        "left_anchors <-> offsets"
4381    );
4382    assert_eq!(
4383        snapshot.summaries_for_anchors::<Point, _>(&left_anchors),
4384        points,
4385        "left_anchors <-> points"
4386    );
4387    assert_eq!(
4388        snapshot.summaries_for_anchors::<MultiBufferOffset, _>(&right_anchors),
4389        offsets,
4390        "right_anchors <-> offsets"
4391    );
4392    assert_eq!(
4393        snapshot.summaries_for_anchors::<Point, _>(&right_anchors),
4394        points,
4395        "right_anchors <-> points"
4396    );
4397
4398    for (anchors, bias) in [(&left_anchors, Bias::Left), (&right_anchors, Bias::Right)] {
4399        for (ix, (offset, anchor)) in offsets.iter().zip(anchors).enumerate() {
4400            if ix > 0 && *offset == MultiBufferOffset(252) && offset > &offsets[ix - 1] {
4401                let prev_anchor = left_anchors[ix - 1];
4402                assert!(
4403                    anchor.cmp(&prev_anchor, snapshot).is_gt(),
4404                    "anchor({}, {bias:?}).cmp(&anchor({}, {bias:?}).is_gt()",
4405                    offsets[ix],
4406                    offsets[ix - 1],
4407                );
4408                assert!(
4409                    prev_anchor.cmp(anchor, snapshot).is_lt(),
4410                    "anchor({}, {bias:?}).cmp(&anchor({}, {bias:?}).is_lt()",
4411                    offsets[ix - 1],
4412                    offsets[ix],
4413                );
4414            }
4415        }
4416    }
4417
4418    if let Some((buffer, offset)) = snapshot.point_to_buffer_offset(snapshot.max_point()) {
4419        assert!(offset.0 <= buffer.len());
4420    }
4421    if let Some((buffer, point)) = snapshot.point_to_buffer_point(snapshot.max_point()) {
4422        assert!(point <= buffer.max_point());
4423    }
4424}
4425
4426fn assert_line_indents(snapshot: &MultiBufferSnapshot) {
4427    let max_row = snapshot.max_point().row;
4428    let buffer_id = snapshot.excerpts().next().unwrap().1.buffer_id;
4429    let text = text::Buffer::new(ReplicaId::LOCAL, buffer_id, snapshot.text());
4430    let mut line_indents = text
4431        .line_indents_in_row_range(0..max_row + 1)
4432        .collect::<Vec<_>>();
4433    for start_row in 0..snapshot.max_point().row {
4434        pretty_assertions::assert_eq!(
4435            snapshot
4436                .line_indents(MultiBufferRow(start_row), |_| true)
4437                .map(|(row, indent, _)| (row.0, indent))
4438                .collect::<Vec<_>>(),
4439            &line_indents[(start_row as usize)..],
4440            "line_indents({start_row})"
4441        );
4442    }
4443
4444    line_indents.reverse();
4445    pretty_assertions::assert_eq!(
4446        snapshot
4447            .reversed_line_indents(MultiBufferRow(max_row), |_| true)
4448            .map(|(row, indent, _)| (row.0, indent))
4449            .collect::<Vec<_>>(),
4450        &line_indents[..],
4451        "reversed_line_indents({max_row})"
4452    );
4453}
4454
4455#[gpui::test]
4456fn test_new_empty_buffer_uses_untitled_title(cx: &mut App) {
4457    let buffer = cx.new(|cx| Buffer::local("", cx));
4458    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4459
4460    assert_eq!(multibuffer.read(cx).title(cx), "untitled");
4461}
4462
4463#[gpui::test]
4464fn test_new_empty_buffer_uses_untitled_title_when_only_contains_whitespace(cx: &mut App) {
4465    let buffer = cx.new(|cx| Buffer::local("\n ", cx));
4466    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4467
4468    assert_eq!(multibuffer.read(cx).title(cx), "untitled");
4469}
4470
4471#[gpui::test]
4472fn test_new_empty_buffer_takes_first_line_for_title(cx: &mut App) {
4473    let buffer = cx.new(|cx| Buffer::local("Hello World\nSecond line", cx));
4474    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4475
4476    assert_eq!(multibuffer.read(cx).title(cx), "Hello World");
4477}
4478
4479#[gpui::test]
4480fn test_new_empty_buffer_takes_trimmed_first_line_for_title(cx: &mut App) {
4481    let buffer = cx.new(|cx| Buffer::local("\nHello, World ", cx));
4482    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4483
4484    assert_eq!(multibuffer.read(cx).title(cx), "Hello, World");
4485}
4486
4487#[gpui::test]
4488fn test_new_empty_buffer_uses_truncated_first_line_for_title(cx: &mut App) {
4489    let title = "aaaaaaaaaabbbbbbbbbbccccccccccddddddddddeeeeeeeeee";
4490    let title_after = "aaaaaaaaaabbbbbbbbbbccccccccccdddddddddd";
4491    let buffer = cx.new(|cx| Buffer::local(title, cx));
4492    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4493
4494    assert_eq!(multibuffer.read(cx).title(cx), title_after);
4495}
4496
4497#[gpui::test]
4498fn test_new_empty_buffer_uses_truncated_first_line_for_title_after_merging_adjacent_spaces(
4499    cx: &mut App,
4500) {
4501    let title = "aaaaaaaaaabbbbbbbbbb    ccccccccccddddddddddeeeeeeeeee";
4502    let title_after = "aaaaaaaaaabbbbbbbbbb ccccccccccddddddddd";
4503    let buffer = cx.new(|cx| Buffer::local(title, cx));
4504    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4505
4506    assert_eq!(multibuffer.read(cx).title(cx), title_after);
4507}
4508
4509#[gpui::test]
4510fn test_new_empty_buffers_title_can_be_set(cx: &mut App) {
4511    let buffer = cx.new(|cx| Buffer::local("Hello World", cx));
4512    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4513    assert_eq!(multibuffer.read(cx).title(cx), "Hello World");
4514
4515    multibuffer.update(cx, |multibuffer, cx| {
4516        multibuffer.set_title("Hey".into(), cx)
4517    });
4518    assert_eq!(multibuffer.read(cx).title(cx), "Hey");
4519}
4520
4521#[gpui::test(iterations = 100)]
4522fn test_random_chunk_bitmaps(cx: &mut App, mut rng: StdRng) {
4523    let multibuffer = if rng.random() {
4524        let len = rng.random_range(0..10000);
4525        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
4526        let buffer = cx.new(|cx| Buffer::local(text, cx));
4527        cx.new(|cx| MultiBuffer::singleton(buffer, cx))
4528    } else {
4529        MultiBuffer::build_random(&mut rng, cx)
4530    };
4531
4532    let snapshot = multibuffer.read(cx).snapshot(cx);
4533
4534    let chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4535
4536    for chunk in chunks {
4537        let chunk_text = chunk.text;
4538        let chars_bitmap = chunk.chars;
4539        let tabs_bitmap = chunk.tabs;
4540
4541        if chunk_text.is_empty() {
4542            assert_eq!(
4543                chars_bitmap, 0,
4544                "Empty chunk should have empty chars bitmap"
4545            );
4546            assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
4547            continue;
4548        }
4549
4550        assert!(
4551            chunk_text.len() <= 128,
4552            "Chunk text length {} exceeds 128 bytes",
4553            chunk_text.len()
4554        );
4555
4556        // Verify chars bitmap
4557        let char_indices = chunk_text
4558            .char_indices()
4559            .map(|(i, _)| i)
4560            .collect::<Vec<_>>();
4561
4562        for byte_idx in 0..chunk_text.len() {
4563            let should_have_bit = char_indices.contains(&byte_idx);
4564            let has_bit = chars_bitmap & (1 << byte_idx) != 0;
4565
4566            if has_bit != should_have_bit {
4567                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4568                eprintln!("Char indices: {:?}", char_indices);
4569                eprintln!("Chars bitmap: {:#b}", chars_bitmap);
4570            }
4571
4572            assert_eq!(
4573                has_bit, should_have_bit,
4574                "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
4575                byte_idx, chunk_text, should_have_bit, has_bit
4576            );
4577        }
4578
4579        for (byte_idx, byte) in chunk_text.bytes().enumerate() {
4580            let is_tab = byte == b'\t';
4581            let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
4582
4583            if has_bit != is_tab {
4584                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4585                eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
4586                assert_eq!(
4587                    has_bit, is_tab,
4588                    "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
4589                    byte_idx, chunk_text, byte as char, is_tab, has_bit
4590                );
4591            }
4592        }
4593    }
4594}
4595
4596#[gpui::test(iterations = 10)]
4597fn test_random_chunk_bitmaps_with_diffs(cx: &mut App, mut rng: StdRng) {
4598    let settings_store = SettingsStore::test(cx);
4599    cx.set_global(settings_store);
4600    use buffer_diff::BufferDiff;
4601    use util::RandomCharIter;
4602
4603    let multibuffer = if rng.random() {
4604        let len = rng.random_range(100..10000);
4605        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
4606        let buffer = cx.new(|cx| Buffer::local(text, cx));
4607        cx.new(|cx| MultiBuffer::singleton(buffer, cx))
4608    } else {
4609        MultiBuffer::build_random(&mut rng, cx)
4610    };
4611
4612    let _diff_count = rng.random_range(1..5);
4613    let mut diffs = Vec::new();
4614
4615    multibuffer.update(cx, |multibuffer, cx| {
4616        for buffer_id in multibuffer.all_buffer_ids() {
4617            if rng.random_bool(0.7) {
4618                if let Some(buffer_handle) = multibuffer.buffer(buffer_id) {
4619                    let buffer_text = buffer_handle.read(cx).text();
4620                    let mut base_text = String::new();
4621
4622                    for line in buffer_text.lines() {
4623                        if rng.random_bool(0.3) {
4624                            continue;
4625                        } else if rng.random_bool(0.3) {
4626                            let line_len = rng.random_range(0..50);
4627                            let modified_line = RandomCharIter::new(&mut rng)
4628                                .take(line_len)
4629                                .collect::<String>();
4630                            base_text.push_str(&modified_line);
4631                            base_text.push('\n');
4632                        } else {
4633                            base_text.push_str(line);
4634                            base_text.push('\n');
4635                        }
4636                    }
4637
4638                    if rng.random_bool(0.5) {
4639                        let extra_lines = rng.random_range(1..5);
4640                        for _ in 0..extra_lines {
4641                            let line_len = rng.random_range(0..50);
4642                            let extra_line = RandomCharIter::new(&mut rng)
4643                                .take(line_len)
4644                                .collect::<String>();
4645                            base_text.push_str(&extra_line);
4646                            base_text.push('\n');
4647                        }
4648                    }
4649
4650                    let diff = cx.new(|cx| {
4651                        BufferDiff::new_with_base_text(
4652                            &base_text,
4653                            &buffer_handle.read(cx).text_snapshot(),
4654                            cx,
4655                        )
4656                    });
4657                    diffs.push(diff.clone());
4658                    multibuffer.add_diff(diff, cx);
4659                }
4660            }
4661        }
4662    });
4663
4664    multibuffer.update(cx, |multibuffer, cx| {
4665        if rng.random_bool(0.5) {
4666            multibuffer.set_all_diff_hunks_expanded(cx);
4667        } else {
4668            let snapshot = multibuffer.snapshot(cx);
4669            let text = snapshot.text();
4670
4671            let mut ranges = Vec::new();
4672            for _ in 0..rng.random_range(1..5) {
4673                if snapshot.len().0 == 0 {
4674                    break;
4675                }
4676
4677                let diff_size = rng.random_range(5..1000);
4678                let mut start = rng.random_range(0..snapshot.len().0);
4679
4680                while !text.is_char_boundary(start) {
4681                    start = start.saturating_sub(1);
4682                }
4683
4684                let mut end = rng.random_range(start..snapshot.len().0.min(start + diff_size));
4685
4686                while !text.is_char_boundary(end) {
4687                    end = end.saturating_add(1);
4688                }
4689                let start_anchor = snapshot.anchor_after(MultiBufferOffset(start));
4690                let end_anchor = snapshot.anchor_before(MultiBufferOffset(end));
4691                ranges.push(start_anchor..end_anchor);
4692            }
4693            multibuffer.expand_diff_hunks(ranges, cx);
4694        }
4695    });
4696
4697    let snapshot = multibuffer.read(cx).snapshot(cx);
4698
4699    let chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4700
4701    for chunk in chunks {
4702        let chunk_text = chunk.text;
4703        let chars_bitmap = chunk.chars;
4704        let tabs_bitmap = chunk.tabs;
4705
4706        if chunk_text.is_empty() {
4707            assert_eq!(
4708                chars_bitmap, 0,
4709                "Empty chunk should have empty chars bitmap"
4710            );
4711            assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
4712            continue;
4713        }
4714
4715        assert!(
4716            chunk_text.len() <= 128,
4717            "Chunk text length {} exceeds 128 bytes",
4718            chunk_text.len()
4719        );
4720
4721        let char_indices = chunk_text
4722            .char_indices()
4723            .map(|(i, _)| i)
4724            .collect::<Vec<_>>();
4725
4726        for byte_idx in 0..chunk_text.len() {
4727            let should_have_bit = char_indices.contains(&byte_idx);
4728            let has_bit = chars_bitmap & (1 << byte_idx) != 0;
4729
4730            if has_bit != should_have_bit {
4731                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4732                eprintln!("Char indices: {:?}", char_indices);
4733                eprintln!("Chars bitmap: {:#b}", chars_bitmap);
4734            }
4735
4736            assert_eq!(
4737                has_bit, should_have_bit,
4738                "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
4739                byte_idx, chunk_text, should_have_bit, has_bit
4740            );
4741        }
4742
4743        for (byte_idx, byte) in chunk_text.bytes().enumerate() {
4744            let is_tab = byte == b'\t';
4745            let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
4746
4747            if has_bit != is_tab {
4748                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4749                eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
4750                assert_eq!(
4751                    has_bit, is_tab,
4752                    "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
4753                    byte_idx, chunk_text, byte as char, is_tab, has_bit
4754                );
4755            }
4756        }
4757    }
4758}
4759
4760fn collect_word_diffs(
4761    base_text: &str,
4762    modified_text: &str,
4763    cx: &mut TestAppContext,
4764) -> Vec<String> {
4765    let buffer = cx.new(|cx| Buffer::local(modified_text, cx));
4766    let diff = cx
4767        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
4768    cx.run_until_parked();
4769
4770    let multibuffer = cx.new(|cx| {
4771        let mut multibuffer = MultiBuffer::singleton(buffer.clone(), cx);
4772        multibuffer.add_diff(diff.clone(), cx);
4773        multibuffer
4774    });
4775
4776    multibuffer.update(cx, |multibuffer, cx| {
4777        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
4778    });
4779
4780    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
4781    let text = snapshot.text();
4782
4783    snapshot
4784        .diff_hunks()
4785        .flat_map(|hunk| hunk.word_diffs)
4786        .map(|range| text[range.start.0..range.end.0].to_string())
4787        .collect()
4788}
4789
4790#[gpui::test]
4791async fn test_word_diff_simple_replacement(cx: &mut TestAppContext) {
4792    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4793    cx.set_global(settings_store);
4794
4795    let base_text = "hello world foo bar\n";
4796    let modified_text = "hello WORLD foo BAR\n";
4797
4798    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4799
4800    assert_eq!(word_diffs, vec!["world", "bar", "WORLD", "BAR"]);
4801}
4802
4803#[gpui::test]
4804async fn test_word_diff_white_space(cx: &mut TestAppContext) {
4805    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4806    cx.set_global(settings_store);
4807
4808    let base_text = "hello world foo bar\n";
4809    let modified_text = "    hello world foo bar\n";
4810
4811    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4812
4813    assert_eq!(word_diffs, vec!["    "]);
4814}
4815
4816#[gpui::test]
4817async fn test_word_diff_consecutive_modified_lines(cx: &mut TestAppContext) {
4818    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4819    cx.set_global(settings_store);
4820
4821    let base_text = "aaa bbb\nccc ddd\n";
4822    let modified_text = "aaa BBB\nccc DDD\n";
4823
4824    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4825
4826    assert_eq!(
4827        word_diffs,
4828        vec!["bbb", "ddd", "BBB", "DDD"],
4829        "consecutive modified lines should produce word diffs when line counts match"
4830    );
4831}
4832
4833#[gpui::test]
4834async fn test_word_diff_modified_lines_with_deletion_between(cx: &mut TestAppContext) {
4835    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4836    cx.set_global(settings_store);
4837
4838    let base_text = "aaa bbb\ndeleted line\nccc ddd\n";
4839    let modified_text = "aaa BBB\nccc DDD\n";
4840
4841    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4842
4843    assert_eq!(
4844        word_diffs,
4845        Vec::<String>::new(),
4846        "modified lines with a deleted line between should not produce word diffs"
4847    );
4848}
4849
4850#[gpui::test]
4851async fn test_word_diff_disabled(cx: &mut TestAppContext) {
4852    let settings_store = cx.update(|cx| {
4853        let mut settings_store = SettingsStore::test(cx);
4854        settings_store.update_user_settings(cx, |settings| {
4855            settings.project.all_languages.defaults.word_diff_enabled = Some(false);
4856        });
4857        settings_store
4858    });
4859    cx.set_global(settings_store);
4860
4861    let base_text = "hello world\n";
4862    let modified_text = "hello WORLD\n";
4863
4864    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4865
4866    assert_eq!(
4867        word_diffs,
4868        Vec::<String>::new(),
4869        "word diffs should be empty when disabled"
4870    );
4871}
4872
4873/// Tests `excerpt_containing` and `excerpts_for_range` (functions mapping multi-buffer text-coordinates to excerpts)
4874#[gpui::test]
4875fn test_excerpts_containment_functions(cx: &mut App) {
4876    // Multibuffer content for these tests:
4877    //    0123
4878    // 0: aa0
4879    // 1: aa1
4880    //    -----
4881    // 2: bb0
4882    // 3: bb1
4883    //    -----MultiBufferOffset(0)..
4884    // 4: cc0
4885
4886    let buffer_1 = cx.new(|cx| Buffer::local("aa0\naa1", cx));
4887    let buffer_2 = cx.new(|cx| Buffer::local("bb0\nbb1", cx));
4888    let buffer_3 = cx.new(|cx| Buffer::local("cc0", cx));
4889
4890    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
4891
4892    let (excerpt_1_info, excerpt_2_info, excerpt_3_info) =
4893        multibuffer.update(cx, |multibuffer, cx| {
4894            multibuffer.set_excerpts_for_path(
4895                PathKey::sorted(0),
4896                buffer_1.clone(),
4897                [Point::new(0, 0)..Point::new(1, 3)],
4898                0,
4899                cx,
4900            );
4901
4902            multibuffer.set_excerpts_for_path(
4903                PathKey::sorted(1),
4904                buffer_2.clone(),
4905                [Point::new(0, 0)..Point::new(1, 3)],
4906                0,
4907                cx,
4908            );
4909
4910            multibuffer.set_excerpts_for_path(
4911                PathKey::sorted(2),
4912                buffer_3.clone(),
4913                [Point::new(0, 0)..Point::new(0, 3)],
4914                0,
4915                cx,
4916            );
4917
4918            let snapshot = multibuffer.snapshot(cx);
4919            let mut infos = snapshot.excerpts().map(|(_, info)| info);
4920            (
4921                infos.next().unwrap(),
4922                infos.next().unwrap(),
4923                infos.next().unwrap(),
4924            )
4925        });
4926
4927    let snapshot = multibuffer.read(cx).snapshot(cx);
4928
4929    assert_eq!(snapshot.text(), "aa0\naa1\nbb0\nbb1\ncc0");
4930
4931    //// Test `excerpts_for_range`
4932
4933    let p00 = snapshot.point_to_offset(Point::new(0, 0));
4934    let p10 = snapshot.point_to_offset(Point::new(1, 0));
4935    let p20 = snapshot.point_to_offset(Point::new(2, 0));
4936    let p23 = snapshot.point_to_offset(Point::new(2, 3));
4937    let p13 = snapshot.point_to_offset(Point::new(1, 3));
4938    let p40 = snapshot.point_to_offset(Point::new(4, 0));
4939    let p43 = snapshot.point_to_offset(Point::new(4, 3));
4940
4941    let excerpts: Vec<_> = snapshot.excerpts_for_range(p00..p00).collect();
4942    assert_eq!(excerpts.len(), 1);
4943    assert_eq!(excerpts[0].info(), excerpt_1_info);
4944
4945    // Cursor at very end of excerpt 3
4946    let excerpts: Vec<_> = snapshot.excerpts_for_range(p43..p43).collect();
4947    assert_eq!(excerpts.len(), 1);
4948    assert_eq!(excerpts[0].info(), excerpt_3_info);
4949
4950    let excerpts: Vec<_> = snapshot.excerpts_for_range(p00..p23).collect();
4951    assert_eq!(excerpts.len(), 2);
4952    assert_eq!(excerpts[0].info(), excerpt_1_info);
4953    assert_eq!(excerpts[1].info(), excerpt_2_info);
4954
4955    // This range represent an selection with end-point just inside excerpt_2
4956    // Today we only expand the first excerpt, but another interpretation that
4957    // we could consider is expanding both here
4958    let excerpts: Vec<_> = snapshot.excerpts_for_range(p10..p20).collect();
4959    assert_eq!(excerpts.len(), 1);
4960    assert_eq!(excerpts[0].info(), excerpt_1_info);
4961
4962    //// Test that `excerpts_for_range` and `excerpt_containing` agree for all single offsets (cursor positions)
4963    for offset in 0..=snapshot.len().0 {
4964        let offset = MultiBufferOffset(offset);
4965        let excerpts_for_range: Vec<_> = snapshot.excerpts_for_range(offset..offset).collect();
4966        assert_eq!(
4967            excerpts_for_range.len(),
4968            1,
4969            "Expected exactly one excerpt for offset {offset}",
4970        );
4971
4972        let excerpt_containing = snapshot.excerpt_containing(offset..offset);
4973        assert!(
4974            excerpt_containing.is_some(),
4975            "Expected excerpt_containing to find excerpt for offset {offset}",
4976        );
4977
4978        assert_eq!(
4979            excerpts_for_range[0].info(),
4980            excerpt_containing.unwrap().excerpt.info(),
4981            "excerpts_for_range and excerpt_containing should agree for offset {offset}",
4982        );
4983    }
4984
4985    //// Test `excerpt_containing` behavior with ranges:
4986
4987    // Ranges intersecting a single-excerpt
4988    let containing = snapshot.excerpt_containing(p00..p13);
4989    assert!(containing.is_some());
4990    assert_eq!(containing.unwrap().excerpt.info(), excerpt_1_info);
4991
4992    // Ranges intersecting multiple excerpts (should return None)
4993    let containing = snapshot.excerpt_containing(p20..p40);
4994    assert!(
4995        containing.is_none(),
4996        "excerpt_containing should return None for ranges spanning multiple excerpts"
4997    );
4998}
4999
5000#[gpui::test]
5001fn test_range_to_buffer_ranges(cx: &mut App) {
5002    let buffer_1 = cx.new(|cx| Buffer::local("aaa\nbbb", cx));
5003    let buffer_2 = cx.new(|cx| Buffer::local("ccc", cx));
5004
5005    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5006    multibuffer.update(cx, |multibuffer, cx| {
5007        multibuffer.set_excerpts_for_path(
5008            PathKey::sorted(0),
5009            buffer_1.clone(),
5010            [Point::new(0, 0)..Point::new(1, 3)],
5011            0,
5012            cx,
5013        );
5014
5015        multibuffer.set_excerpts_for_path(
5016            PathKey::sorted(1),
5017            buffer_2.clone(),
5018            [Point::new(0, 0)..Point::new(0, 3)],
5019            0,
5020            cx,
5021        );
5022    });
5023
5024    let snapshot = multibuffer.read(cx).snapshot(cx);
5025    assert_eq!(snapshot.text(), "aaa\nbbb\nccc");
5026
5027    let excerpt_2_start = Point::new(2, 0);
5028
5029    let ranges_half_open = snapshot.range_to_buffer_ranges(Point::zero()..excerpt_2_start);
5030    assert_eq!(
5031        ranges_half_open.len(),
5032        1,
5033        "Half-open range ending at excerpt start should EXCLUDE that excerpt"
5034    );
5035    assert_eq!(ranges_half_open[0].1, BufferOffset(0)..BufferOffset(7));
5036    assert_eq!(
5037        ranges_half_open[0].0.remote_id(),
5038        buffer_1.read(cx).remote_id()
5039    );
5040
5041    let buffer_empty = cx.new(|cx| Buffer::local("", cx));
5042    let multibuffer_trailing_empty = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5043    let (te_excerpt_1_info, te_excerpt_2_info) =
5044        multibuffer_trailing_empty.update(cx, |multibuffer, cx| {
5045            multibuffer.set_excerpts_for_path(
5046                PathKey::sorted(0),
5047                buffer_1.clone(),
5048                [Point::new(0, 0)..Point::new(1, 3)],
5049                0,
5050                cx,
5051            );
5052
5053            multibuffer.set_excerpts_for_path(
5054                PathKey::sorted(1),
5055                buffer_empty.clone(),
5056                [Point::new(0, 0)..Point::new(0, 0)],
5057                0,
5058                cx,
5059            );
5060
5061            let snapshot = multibuffer.snapshot(cx);
5062            let mut infos = snapshot.excerpts().map(|(_, info)| info);
5063            (infos.next().unwrap(), infos.next().unwrap())
5064        });
5065
5066    let snapshot_trailing = multibuffer_trailing_empty.read(cx).snapshot(cx);
5067    assert_eq!(snapshot_trailing.text(), "aaa\nbbb\n");
5068
5069    let max_point = snapshot_trailing.max_point();
5070
5071    let ranges_half_open_max =
5072        snapshot_trailing.range_to_buffer_ranges_with_context(Point::zero()..max_point);
5073    assert_eq!(
5074        ranges_half_open_max.len(),
5075        2,
5076        "Should include trailing empty excerpts"
5077    );
5078    assert_eq!(ranges_half_open_max[0].2, te_excerpt_1_info.range);
5079}
5080
5081#[gpui::test]
5082fn test_cannot_seek_backward_after_excerpt_replacement(cx: &mut TestAppContext) {
5083    let buffer_b_text: String = (0..50).map(|i| format!("line_b {i}\n")).collect();
5084    let buffer_b = cx.new(|cx| Buffer::local(buffer_b_text, cx));
5085
5086    let buffer_c_text: String = (0..10).map(|i| format!("line_c {i}\n")).collect();
5087    let buffer_c = cx.new(|cx| Buffer::local(buffer_c_text, cx));
5088
5089    let buffer_d_text: String = (0..10).map(|i| format!("line_d {i}\n")).collect();
5090    let buffer_d = cx.new(|cx| Buffer::local(buffer_d_text, cx));
5091
5092    let path_b = PathKey::with_sort_prefix(0, rel_path("bbb.rs").into_arc());
5093    let path_c = PathKey::with_sort_prefix(0, rel_path("ddd.rs").into_arc());
5094    let path_d = PathKey::with_sort_prefix(0, rel_path("ccc.rs").into_arc());
5095
5096    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5097
5098    multibuffer.update(cx, |multibuffer, cx| {
5099        multibuffer.set_excerpts_for_path(
5100            path_b.clone(),
5101            buffer_b.clone(),
5102            vec![
5103                Point::row_range(0..3),
5104                Point::row_range(15..18),
5105                Point::row_range(30..33),
5106            ],
5107            0,
5108            cx,
5109        );
5110    });
5111
5112    multibuffer.update(cx, |multibuffer, cx| {
5113        multibuffer.set_excerpts_for_path(
5114            path_c.clone(),
5115            buffer_c.clone(),
5116            vec![Point::row_range(0..3)],
5117            0,
5118            cx,
5119        );
5120    });
5121
5122    let (anchor_in_e_b2, anchor_in_e_b3) = multibuffer.read_with(cx, |multibuffer, cx| {
5123        let snapshot = multibuffer.snapshot(cx);
5124        let excerpt_infos: Vec<ExcerptInfo> = snapshot.excerpts().map(|(_, info)| info).collect();
5125        assert_eq!(excerpt_infos.len(), 4, "expected 4 excerpts (3×B + 1×C)");
5126
5127        let e_b2_info = excerpt_infos[1].clone();
5128        let e_b3_info = excerpt_infos[2].clone();
5129
5130        let anchor_b2 = Anchor::in_buffer(e_b2_info.path_key_index, e_b2_info.range.start);
5131        let anchor_b3 = Anchor::in_buffer(e_b3_info.path_key_index, e_b3_info.range.start);
5132        (anchor_b2, anchor_b3)
5133    });
5134
5135    multibuffer.update(cx, |multibuffer, cx| {
5136        multibuffer.set_excerpts_for_path(
5137            path_b.clone(),
5138            buffer_b.clone(),
5139            vec![Point::row_range(0..3), Point::row_range(28..36)],
5140            0,
5141            cx,
5142        );
5143    });
5144
5145    multibuffer.update(cx, |multibuffer, cx| {
5146        multibuffer.set_excerpts_for_path(
5147            path_d.clone(),
5148            buffer_d.clone(),
5149            vec![Point::row_range(0..3)],
5150            0,
5151            cx,
5152        );
5153    });
5154
5155    multibuffer.read_with(cx, |multibuffer, cx| {
5156        let snapshot = multibuffer.snapshot(cx);
5157        snapshot.summaries_for_anchors::<Point, _>(&[anchor_in_e_b2, anchor_in_e_b3]);
5158    });
5159}