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(Clone, 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        let mut new_ranges = self
2308            .excerpts
2309            .iter()
2310            .map(|excerpt| {
2311                (
2312                    excerpt.clone(),
2313                    excerpt.range.to_point(&excerpt.buffer.read(cx).snapshot()),
2314                )
2315            })
2316            .collect::<Vec<_>>();
2317
2318        for (excerpt, point_range) in &mut new_ranges {
2319            if excerpts.contains(&excerpt.info(cx)) {
2320                let snapshot = excerpt.buffer.read(cx).snapshot();
2321                point_range.start = Point::new(point_range.start.row.saturating_sub(line_count), 0);
2322                point_range.end = snapshot
2323                    .clip_point(Point::new(point_range.end.row + line_count, 0), Bias::Left);
2324                point_range.end.column = snapshot.line_len(point_range.end.row);
2325            }
2326        }
2327
2328        for ((path_key, path_key_index, buffer), chunk) in
2329            &new_ranges.iter().chunk_by(|(excerpt, _)| {
2330                (
2331                    excerpt.path_key.clone(),
2332                    excerpt.path_key_index,
2333                    excerpt.buffer.clone(),
2334                )
2335            })
2336        {
2337            let buffer_snapshot = buffer.read(cx).snapshot();
2338            self.set_excerpts(
2339                path_key,
2340                path_key_index,
2341                buffer,
2342                &buffer_snapshot,
2343                chunk
2344                    .map(|(_, range)| ExcerptRange::new(range.clone()))
2345                    .collect::<Vec<_>>(),
2346            );
2347        }
2348    }
2349
2350    fn set_excerpts(
2351        &mut self,
2352        path_key: PathKey,
2353        path_key_index: PathKeyIndex,
2354        buffer: Entity<Buffer>,
2355        buffer_snapshot: &BufferSnapshot,
2356        ranges: Vec<ExcerptRange<Point>>,
2357    ) {
2358        self.excerpts.retain(|excerpt| {
2359            excerpt.path_key != path_key && excerpt.buffer.entity_id() != buffer.entity_id()
2360        });
2361
2362        let ranges = MultiBuffer::merge_excerpt_ranges(&ranges);
2363
2364        let (Ok(ix) | Err(ix)) = self
2365            .excerpts
2366            .binary_search_by(|probe| probe.path_key.cmp(&path_key));
2367        self.excerpts.splice(
2368            ix..ix,
2369            ranges.into_iter().map(|range| ReferenceExcerpt {
2370                path_key: path_key.clone(),
2371                path_key_index,
2372                buffer: buffer.clone(),
2373                range: buffer_snapshot.anchor_before(range.context.start)
2374                    ..buffer_snapshot.anchor_after(range.context.end),
2375            }),
2376        );
2377    }
2378
2379    fn expand_diff_hunks(&mut self, path_key: PathKey, range: Range<text::Anchor>, cx: &App) {
2380        let excerpt = self
2381            .excerpts
2382            .iter_mut()
2383            .find(|e| {
2384                e.path_key == path_key
2385                    && e.range
2386                        .start
2387                        .cmp(&range.start, &e.buffer.read(cx).snapshot())
2388                        .is_le()
2389            })
2390            .unwrap();
2391        let buffer = excerpt.buffer.read(cx).snapshot();
2392        let buffer_id = buffer.remote_id();
2393
2394        // Skip inverted excerpts - hunks are always expanded
2395        if self.inverted_diffs.contains_key(&buffer_id) {
2396            return;
2397        }
2398
2399        let Some(diff) = self.diffs.get(&buffer_id) else {
2400            return;
2401        };
2402        let excerpt_range = excerpt.range.to_offset(&buffer);
2403        let expanded_diff_hunks = self
2404            .expanded_diff_hunks_by_buffer
2405            .entry(buffer_id)
2406            .or_default();
2407        for hunk in diff
2408            .read(cx)
2409            .snapshot(cx)
2410            .hunks_intersecting_range(range, &buffer)
2411        {
2412            let hunk_range = hunk.buffer_range.to_offset(&buffer);
2413            if hunk_range.start < excerpt_range.start || hunk_range.start > excerpt_range.end {
2414                continue;
2415            }
2416            if let Err(ix) = expanded_diff_hunks
2417                .binary_search_by(|anchor| anchor.cmp(&hunk.buffer_range.start, &buffer))
2418            {
2419                log::info!(
2420                    "expanding diff hunk {:?}. excerpt range:{:?}",
2421                    hunk_range,
2422                    excerpt_range
2423                );
2424                expanded_diff_hunks.insert(ix, hunk.buffer_range.start);
2425            } else {
2426                log::trace!("hunk {hunk_range:?} already expanded in excerpt");
2427            }
2428        }
2429    }
2430
2431    fn expected_content(&self, cx: &App) -> (String, Vec<RowInfo>, HashSet<MultiBufferRow>) {
2432        let mut text = String::new();
2433        let mut regions = Vec::<ReferenceRegion>::new();
2434        let mut excerpt_boundary_rows = HashSet::default();
2435        for excerpt in &self.excerpts {
2436            excerpt_boundary_rows.insert(MultiBufferRow(text.matches('\n').count() as u32));
2437            let buffer = excerpt.buffer.read(cx);
2438            let buffer_id = buffer.remote_id();
2439            let buffer_range = excerpt.range.to_offset(buffer);
2440
2441            if let Some((diff, main_buffer)) = self.inverted_diffs.get(&buffer_id) {
2442                let diff_snapshot = diff.read(cx).snapshot(cx);
2443                let main_buffer_snapshot = main_buffer.read(cx).snapshot();
2444
2445                let mut offset = buffer_range.start;
2446                for hunk in diff_snapshot.hunks_intersecting_base_text_range(
2447                    buffer_range.clone(),
2448                    &main_buffer_snapshot.text,
2449                ) {
2450                    let mut hunk_base_range = hunk.diff_base_byte_range.clone();
2451
2452                    hunk_base_range.end = hunk_base_range.end.min(buffer_range.end);
2453                    if hunk_base_range.start > buffer_range.end
2454                        || hunk_base_range.start < buffer_range.start
2455                    {
2456                        continue;
2457                    }
2458
2459                    // Add the text before the hunk
2460                    if hunk_base_range.start >= offset {
2461                        let len = text.len();
2462                        text.extend(buffer.text_for_range(offset..hunk_base_range.start));
2463                        if text.len() > len {
2464                            regions.push(ReferenceRegion {
2465                                buffer_id: Some(buffer_id),
2466                                range: len..text.len(),
2467                                buffer_range: Some(
2468                                    (offset..hunk_base_range.start).to_point(&buffer),
2469                                ),
2470                                status: None,
2471                                excerpt_info: Some(excerpt.info(cx)),
2472                            });
2473                        }
2474                    }
2475
2476                    // Add the "deleted" region (base text that's not in main)
2477                    if !hunk_base_range.is_empty() {
2478                        let len = text.len();
2479                        text.extend(buffer.text_for_range(hunk_base_range.clone()));
2480                        regions.push(ReferenceRegion {
2481                            buffer_id: Some(buffer_id),
2482                            range: len..text.len(),
2483                            buffer_range: Some(hunk_base_range.to_point(&buffer)),
2484                            status: Some(DiffHunkStatus::deleted(hunk.secondary_status)),
2485                            excerpt_info: Some(excerpt.info(cx)),
2486                        });
2487                    }
2488
2489                    offset = hunk_base_range.end;
2490                }
2491
2492                // Add remaining buffer text
2493                let len = text.len();
2494                text.extend(buffer.text_for_range(offset..buffer_range.end));
2495                text.push('\n');
2496                regions.push(ReferenceRegion {
2497                    buffer_id: Some(buffer_id),
2498                    range: len..text.len(),
2499                    buffer_range: Some((offset..buffer_range.end).to_point(&buffer)),
2500                    status: None,
2501                    excerpt_info: Some(excerpt.info(cx)),
2502                });
2503            } else {
2504                let diff = self.diffs.get(&buffer_id).unwrap().read(cx).snapshot(cx);
2505                let base_buffer = diff.base_text();
2506
2507                let mut offset = buffer_range.start;
2508                let hunks = diff
2509                    .hunks_intersecting_range(excerpt.range.clone(), buffer)
2510                    .peekable();
2511
2512                for hunk in hunks {
2513                    // Ignore hunks that are outside the excerpt range.
2514                    let mut hunk_range = hunk.buffer_range.to_offset(buffer);
2515
2516                    hunk_range.end = hunk_range.end.min(buffer_range.end);
2517                    if hunk_range.start > buffer_range.end || hunk_range.start < buffer_range.start
2518                    {
2519                        log::trace!("skipping hunk outside excerpt range");
2520                        continue;
2521                    }
2522
2523                    if !self
2524                        .expanded_diff_hunks_by_buffer
2525                        .get(&buffer_id)
2526                        .cloned()
2527                        .into_iter()
2528                        .flatten()
2529                        .any(|expanded_anchor| {
2530                            expanded_anchor.to_offset(buffer).max(buffer_range.start)
2531                                == hunk_range.start.max(buffer_range.start)
2532                        })
2533                    {
2534                        log::trace!("skipping a hunk that's not marked as expanded");
2535                        continue;
2536                    }
2537
2538                    if !hunk.buffer_range.start.is_valid(buffer) {
2539                        log::trace!("skipping hunk with deleted start: {:?}", hunk.range);
2540                        continue;
2541                    }
2542
2543                    if hunk_range.start >= offset {
2544                        // Add the buffer text before the hunk
2545                        let len = text.len();
2546                        text.extend(buffer.text_for_range(offset..hunk_range.start));
2547                        if text.len() > len {
2548                            regions.push(ReferenceRegion {
2549                                buffer_id: Some(buffer_id),
2550                                range: len..text.len(),
2551                                buffer_range: Some((offset..hunk_range.start).to_point(&buffer)),
2552                                status: None,
2553                                excerpt_info: Some(excerpt.info(cx)),
2554                            });
2555                        }
2556
2557                        // Add the deleted text for the hunk.
2558                        if !hunk.diff_base_byte_range.is_empty() {
2559                            let mut base_text = base_buffer
2560                                .text_for_range(hunk.diff_base_byte_range.clone())
2561                                .collect::<String>();
2562                            if !base_text.ends_with('\n') {
2563                                base_text.push('\n');
2564                            }
2565                            let len = text.len();
2566                            text.push_str(&base_text);
2567                            regions.push(ReferenceRegion {
2568                                buffer_id: Some(base_buffer.remote_id()),
2569                                range: len..text.len(),
2570                                buffer_range: Some(
2571                                    hunk.diff_base_byte_range.to_point(&base_buffer),
2572                                ),
2573                                status: Some(DiffHunkStatus::deleted(hunk.secondary_status)),
2574                                excerpt_info: Some(excerpt.info(cx)),
2575                            });
2576                        }
2577
2578                        offset = hunk_range.start;
2579                    }
2580
2581                    // Add the inserted text for the hunk.
2582                    if hunk_range.end > offset {
2583                        let len = text.len();
2584                        text.extend(buffer.text_for_range(offset..hunk_range.end));
2585                        let range = len..text.len();
2586                        let region = ReferenceRegion {
2587                            buffer_id: Some(buffer_id),
2588                            range,
2589                            buffer_range: Some((offset..hunk_range.end).to_point(&buffer)),
2590                            status: Some(DiffHunkStatus::added(hunk.secondary_status)),
2591                            excerpt_info: Some(excerpt.info(cx)),
2592                        };
2593                        offset = hunk_range.end;
2594                        regions.push(region);
2595                    }
2596                }
2597
2598                // Add the buffer text for the rest of the excerpt.
2599                let len = text.len();
2600                text.extend(buffer.text_for_range(offset..buffer_range.end));
2601                text.push('\n');
2602                regions.push(ReferenceRegion {
2603                    buffer_id: Some(buffer_id),
2604                    range: len..text.len(),
2605                    buffer_range: Some((offset..buffer_range.end).to_point(&buffer)),
2606                    status: None,
2607                    excerpt_info: Some(excerpt.info(cx)),
2608                });
2609            }
2610        }
2611
2612        // Remove final trailing newline.
2613        if self.excerpts.is_empty() {
2614            regions.push(ReferenceRegion {
2615                buffer_id: None,
2616                range: 0..1,
2617                buffer_range: Some(Point::new(0, 0)..Point::new(0, 1)),
2618                status: None,
2619                excerpt_info: None,
2620            });
2621        } else {
2622            text.pop();
2623        }
2624
2625        // Retrieve the row info using the region that contains
2626        // the start of each multi-buffer line.
2627        let mut ix = 0;
2628        let row_infos = text
2629            .split('\n')
2630            .map(|line| {
2631                let row_info = regions
2632                    .iter()
2633                    .position(|region| region.range.contains(&ix))
2634                    .map_or(RowInfo::default(), |region_ix| {
2635                        let region = regions[region_ix].clone();
2636                        let buffer_row = region.buffer_range.as_ref().map(|buffer_range| {
2637                            buffer_range.start.row
2638                                + text[region.range.start..ix].matches('\n').count() as u32
2639                        });
2640                        let main_buffer = self
2641                            .excerpts
2642                            .iter()
2643                            .find(|e| e.info(cx) == region.excerpt_info.clone().unwrap())
2644                            .map(|e| e.buffer.clone());
2645                        let is_excerpt_start = region_ix == 0
2646                            || &regions[region_ix - 1].excerpt_info != &region.excerpt_info
2647                            || regions[region_ix - 1].range.is_empty();
2648                        let mut is_excerpt_end = region_ix == regions.len() - 1
2649                            || &regions[region_ix + 1].excerpt_info != &region.excerpt_info;
2650                        let is_start = !text[region.range.start..ix].contains('\n');
2651                        let mut is_end = if region.range.end > text.len() {
2652                            !text[ix..].contains('\n')
2653                        } else {
2654                            text[ix..region.range.end.min(text.len())]
2655                                .matches('\n')
2656                                .count()
2657                                == 1
2658                        };
2659                        if region_ix < regions.len() - 1
2660                            && !text[ix..].contains("\n")
2661                            && (region.status == Some(DiffHunkStatus::added_none())
2662                                || region.status.is_some_and(|s| s.is_deleted()))
2663                            && regions[region_ix + 1].excerpt_info == region.excerpt_info
2664                            && regions[region_ix + 1].range.start == text.len()
2665                        {
2666                            is_end = true;
2667                            is_excerpt_end = true;
2668                        }
2669                        let multibuffer_row =
2670                            MultiBufferRow(text[..ix].matches('\n').count() as u32);
2671                        let mut expand_direction = None;
2672                        if let Some(buffer) = &main_buffer {
2673                            let buffer_row = buffer_row.unwrap();
2674                            let needs_expand_up = is_excerpt_start && is_start && buffer_row > 0;
2675                            let needs_expand_down = is_excerpt_end
2676                                && is_end
2677                                && buffer.read(cx).max_point().row > buffer_row;
2678                            expand_direction = if needs_expand_up && needs_expand_down {
2679                                Some(ExpandExcerptDirection::UpAndDown)
2680                            } else if needs_expand_up {
2681                                Some(ExpandExcerptDirection::Up)
2682                            } else if needs_expand_down {
2683                                Some(ExpandExcerptDirection::Down)
2684                            } else {
2685                                None
2686                            };
2687                        }
2688                        RowInfo {
2689                            buffer_id: region.buffer_id,
2690                            diff_status: region.status,
2691                            buffer_row,
2692                            wrapped_buffer_row: None,
2693
2694                            multibuffer_row: Some(multibuffer_row),
2695                            expand_info: expand_direction.zip(region.excerpt_info.clone()).map(
2696                                |(direction, excerpt_info)| ExpandInfo {
2697                                    direction,
2698                                    excerpt_range: excerpt_info.range,
2699                                },
2700                            ),
2701                        }
2702                    });
2703                ix += line.len() + 1;
2704                row_info
2705            })
2706            .collect();
2707
2708        (text, row_infos, excerpt_boundary_rows)
2709    }
2710
2711    fn diffs_updated(&mut self, cx: &App) {
2712        for excerpt in &mut self.excerpts {
2713            let buffer = excerpt.buffer.read(cx).snapshot();
2714            let buffer_id = buffer.remote_id();
2715
2716            // Skip inverted diff excerpts - hunks are always expanded
2717            if self.inverted_diffs.contains_key(&buffer_id) {
2718                continue;
2719            }
2720
2721            let excerpt_range = excerpt.range.to_offset(&buffer);
2722            let Some(diff) = self.diffs.get(&buffer_id) else {
2723                continue;
2724            };
2725            let diff = diff.read(cx).snapshot(cx);
2726            let mut hunks = diff.hunks_in_row_range(0..u32::MAX, &buffer).peekable();
2727            self.expanded_diff_hunks_by_buffer
2728                .entry(buffer_id)
2729                .or_default()
2730                .retain(|hunk_anchor| {
2731                    if !hunk_anchor.is_valid(&buffer) {
2732                        return false;
2733                    }
2734                    while let Some(hunk) = hunks.peek() {
2735                        match hunk.buffer_range.start.cmp(hunk_anchor, &buffer) {
2736                            cmp::Ordering::Less => {
2737                                hunks.next();
2738                            }
2739                            cmp::Ordering::Equal => {
2740                                let hunk_range = hunk.buffer_range.to_offset(&buffer);
2741                                return hunk_range.end >= excerpt_range.start
2742                                    && hunk_range.start <= excerpt_range.end;
2743                            }
2744                            cmp::Ordering::Greater => break,
2745                        }
2746                    }
2747                    false
2748                });
2749        }
2750    }
2751
2752    fn add_diff(&mut self, diff: Entity<BufferDiff>, cx: &mut App) {
2753        let buffer_id = diff.read(cx).buffer_id;
2754        self.diffs.insert(buffer_id, diff);
2755    }
2756
2757    fn add_inverted_diff(
2758        &mut self,
2759        diff: Entity<BufferDiff>,
2760        main_buffer: Entity<language::Buffer>,
2761        cx: &App,
2762    ) {
2763        let base_text_buffer_id = diff.read(cx).base_text(cx).remote_id();
2764        self.inverted_diffs
2765            .insert(base_text_buffer_id, (diff, main_buffer));
2766    }
2767}
2768
2769#[gpui::test(iterations = 100)]
2770async fn test_random_set_ranges(cx: &mut TestAppContext, mut rng: StdRng) {
2771    let base_text = "a\n".repeat(100);
2772    let buf = cx.update(|cx| cx.new(|cx| Buffer::local(base_text, cx)));
2773    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
2774
2775    let operations = env::var("OPERATIONS")
2776        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2777        .unwrap_or(10);
2778
2779    fn row_ranges(ranges: &Vec<Range<Point>>) -> Vec<Range<u32>> {
2780        ranges
2781            .iter()
2782            .map(|range| range.start.row..range.end.row)
2783            .collect()
2784    }
2785
2786    for _ in 0..operations {
2787        let snapshot = buf.update(cx, |buf, _| buf.snapshot());
2788        let num_ranges = rng.random_range(0..=10);
2789        let max_row = snapshot.max_point().row;
2790        let mut ranges = (0..num_ranges)
2791            .map(|_| {
2792                let start = rng.random_range(0..max_row);
2793                let end = rng.random_range(start + 1..max_row + 1);
2794                Point::row_range(start..end)
2795            })
2796            .collect::<Vec<_>>();
2797        ranges.sort_by_key(|range| range.start);
2798        log::info!("Setting ranges: {:?}", row_ranges(&ranges));
2799        let (created, _) = multibuffer.update(cx, |multibuffer, cx| {
2800            multibuffer.set_excerpts_for_path(
2801                PathKey::for_buffer(&buf, cx),
2802                buf.clone(),
2803                ranges.clone(),
2804                2,
2805                cx,
2806            )
2807        });
2808
2809        assert_eq!(created.len(), ranges.len());
2810
2811        let snapshot = multibuffer.update(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2812        let mut last_end = None;
2813        let mut seen_ranges = Vec::default();
2814
2815        for (buf, info) in snapshot.excerpts() {
2816            let start = info.range.start.to_point(buf);
2817            let end = info.range.end.to_point(buf);
2818            seen_ranges.push(start..end);
2819
2820            if let Some(last_end) = last_end.take() {
2821                assert!(
2822                    start > last_end,
2823                    "multibuffer has out-of-order ranges: {:?}; {:?} <= {:?}",
2824                    row_ranges(&seen_ranges),
2825                    start,
2826                    last_end
2827                )
2828            }
2829
2830            ranges.retain(|range| range.start < start || range.end > end);
2831
2832            last_end = Some(end)
2833        }
2834
2835        assert!(
2836            ranges.is_empty(),
2837            "multibuffer {:?} did not include all ranges: {:?}",
2838            row_ranges(&seen_ranges),
2839            row_ranges(&ranges)
2840        );
2841    }
2842}
2843
2844#[gpui::test(iterations = 100)]
2845async fn test_random_multibuffer(cx: &mut TestAppContext, mut rng: StdRng) {
2846    let operations = env::var("OPERATIONS")
2847        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2848        .unwrap_or(10);
2849    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
2850    let mut buffers: Vec<Entity<Buffer>> = Vec::new();
2851    let mut base_texts: HashMap<BufferId, String> = HashMap::default();
2852    let mut reference = ReferenceMultibuffer::default();
2853    let mut anchors = Vec::new();
2854    let mut old_versions = Vec::new();
2855    let mut needs_diff_calculation = false;
2856    let mut inverted_diff_main_buffers: HashMap<BufferId, Entity<BufferDiff>> = HashMap::default();
2857    for _ in 0..operations {
2858        match rng.random_range(0..100) {
2859            0..=14 if !buffers.is_empty() => {
2860                let buffer = buffers.choose(&mut rng).unwrap();
2861                buffer.update(cx, |buf, cx| {
2862                    let edit_count = rng.random_range(1..5);
2863                    buf.randomly_edit(&mut rng, edit_count, cx);
2864                    log::info!("buffer text:\n{}", buf.text());
2865                    needs_diff_calculation = true;
2866                });
2867                cx.update(|cx| reference.diffs_updated(cx));
2868            }
2869            15..=24 if !reference.excerpts.is_empty() => {
2870                multibuffer.update(cx, |multibuffer, cx| {
2871                    let snapshot = multibuffer.snapshot(cx);
2872                    let infos = snapshot
2873                        .excerpts()
2874                        .map(|(_, info)| info)
2875                        .collect::<Vec<_>>();
2876                    let mut excerpts = HashSet::default();
2877                    for _ in 0..rng.random_range(0..infos.len()) {
2878                        excerpts.extend(infos.choose(&mut rng).cloned());
2879                    }
2880
2881                    let line_count = rng.random_range(0..5);
2882
2883                    let excerpt_ixs = excerpts
2884                        .iter()
2885                        .map(|info| {
2886                            reference
2887                                .excerpts
2888                                .iter()
2889                                .position(|e| e.info(cx) == *info)
2890                                .unwrap()
2891                        })
2892                        .collect::<Vec<_>>();
2893                    log::info!("Expanding excerpts {excerpt_ixs:?} by {line_count} lines");
2894                    multibuffer.expand_excerpts(
2895                        excerpts
2896                            .iter()
2897                            .map(|info| Anchor::in_buffer(info.path_key_index, info.range.end)),
2898                        line_count,
2899                        ExpandExcerptDirection::UpAndDown,
2900                        cx,
2901                    );
2902
2903                    reference.expand_excerpts(&excerpts, line_count, cx);
2904                });
2905            }
2906            25..=34 if !reference.excerpts.is_empty() => {
2907                let multibuffer =
2908                    multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
2909                let offset = multibuffer.clip_offset(
2910                    MultiBufferOffset(rng.random_range(0..=multibuffer.len().0)),
2911                    Bias::Left,
2912                );
2913                let bias = if rng.random() {
2914                    Bias::Left
2915                } else {
2916                    Bias::Right
2917                };
2918                log::info!("Creating anchor at {} with bias {:?}", offset.0, bias);
2919                anchors.push(multibuffer.anchor_at(offset, bias));
2920                anchors.sort_by(|a, b| a.cmp(b, &multibuffer));
2921            }
2922            35..=45 if !reference.excerpts.is_empty() => {
2923                multibuffer.update(cx, |multibuffer, cx| {
2924                    let snapshot = multibuffer.snapshot(cx);
2925                    let excerpt_ix = rng.random_range(0..reference.excerpts.len());
2926                    let excerpt = &reference.excerpts[excerpt_ix];
2927
2928                    // Skip inverted excerpts - hunks can't be collapsed
2929                    let buffer_id = excerpt.buffer.read(cx).remote_id();
2930                    if reference.inverted_diffs.contains_key(&buffer_id) {
2931                        return;
2932                    }
2933
2934                    let start = excerpt.range.start;
2935                    let end = excerpt.range.end;
2936                    let range = snapshot.anchor_in_buffer(excerpt.info(cx).buffer_id, start).unwrap()
2937                        ..snapshot.anchor_in_buffer(excerpt.info(cx).buffer_id, end).unwrap();
2938
2939                    log::info!(
2940                        "expanding diff hunks in range {:?} (excerpt index {excerpt_ix:?}, buffer id {:?})",
2941                        range.to_offset(&snapshot),
2942                        buffer_id,
2943                    );
2944                    reference.expand_diff_hunks(excerpt.path_key.clone(), start..end, cx);
2945                    multibuffer.expand_diff_hunks(vec![range], cx);
2946                });
2947            }
2948            46..=75 if needs_diff_calculation => {
2949                multibuffer.update(cx, |multibuffer, cx| {
2950                    for buffer in multibuffer.all_buffers() {
2951                        let snapshot = buffer.read(cx).snapshot();
2952                        let buffer_id = snapshot.remote_id();
2953
2954                        if let Some(diff) = multibuffer.diff_for(buffer_id) {
2955                            diff.update(cx, |diff, cx| {
2956                                log::info!("recalculating diff for buffer {:?}", buffer_id,);
2957                                diff.recalculate_diff_sync(&snapshot.text, cx);
2958                            });
2959                        }
2960
2961                        if let Some(inverted_diff) = inverted_diff_main_buffers.get(&buffer_id) {
2962                            inverted_diff.update(cx, |diff, cx| {
2963                                log::info!(
2964                                    "recalculating inverted diff for main buffer {:?}",
2965                                    buffer_id,
2966                                );
2967                                diff.recalculate_diff_sync(&snapshot.text, cx);
2968                            });
2969                        }
2970                    }
2971                    reference.diffs_updated(cx);
2972                    needs_diff_calculation = false;
2973                });
2974            }
2975            _ => {
2976                // Decide if we're creating a new buffer or reusing an existing one
2977                let create_new_buffer = buffers.is_empty() || rng.random_bool(0.4);
2978
2979                let (excerpt_buffer, diff, inverted_main_buffer) = if create_new_buffer {
2980                    let create_inverted = rng.random_bool(0.3);
2981
2982                    if create_inverted {
2983                        let mut main_buffer_text = util::RandomCharIter::new(&mut rng)
2984                            .take(256)
2985                            .collect::<String>();
2986                        let main_buffer = cx.new(|cx| Buffer::local(main_buffer_text.clone(), cx));
2987                        text::LineEnding::normalize(&mut main_buffer_text);
2988                        let main_buffer_id =
2989                            main_buffer.read_with(cx, |buffer, _| buffer.remote_id());
2990                        base_texts.insert(main_buffer_id, main_buffer_text.clone());
2991                        buffers.push(main_buffer.clone());
2992
2993                        let diff = cx.new(|cx| {
2994                            BufferDiff::new_with_base_text(
2995                                &main_buffer_text,
2996                                &main_buffer.read(cx).text_snapshot(),
2997                                cx,
2998                            )
2999                        });
3000
3001                        let base_text_buffer =
3002                            diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3003
3004                        // Track for recalculation when main buffer is edited
3005                        inverted_diff_main_buffers.insert(main_buffer_id, diff.clone());
3006
3007                        (base_text_buffer, diff, Some(main_buffer))
3008                    } else {
3009                        let mut base_text = util::RandomCharIter::new(&mut rng)
3010                            .take(256)
3011                            .collect::<String>();
3012
3013                        let buffer_handle = cx.new(|cx| Buffer::local(base_text.clone(), cx));
3014                        text::LineEnding::normalize(&mut base_text);
3015                        let buffer_id = buffer_handle.read_with(cx, |buffer, _| buffer.remote_id());
3016                        base_texts.insert(buffer_id, base_text.clone());
3017                        buffers.push(buffer_handle.clone());
3018
3019                        let diff = cx.new(|cx| {
3020                            BufferDiff::new_with_base_text(
3021                                &base_text,
3022                                &buffer_handle.read(cx).text_snapshot(),
3023                                cx,
3024                            )
3025                        });
3026
3027                        (buffer_handle, diff, None)
3028                    }
3029                } else {
3030                    // Reuse an existing buffer
3031                    let buffer_handle = buffers.choose(&mut rng).unwrap().clone();
3032                    let buffer_id = buffer_handle.read_with(cx, |buffer, _| buffer.remote_id());
3033
3034                    if let Some(diff) = inverted_diff_main_buffers.get(&buffer_id) {
3035                        let base_text_buffer =
3036                            diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3037                        (base_text_buffer, diff.clone(), Some(buffer_handle))
3038                    } else {
3039                        // Get existing diff or create new one for regular buffer
3040                        let diff = multibuffer
3041                            .read_with(cx, |mb, _| mb.diff_for(buffer_id))
3042                            .unwrap_or_else(|| {
3043                                let base_text = base_texts.get(&buffer_id).unwrap();
3044                                cx.new(|cx| {
3045                                    BufferDiff::new_with_base_text(
3046                                        base_text,
3047                                        &buffer_handle.read(cx).text_snapshot(),
3048                                        cx,
3049                                    )
3050                                })
3051                            });
3052                        (buffer_handle, diff, None)
3053                    }
3054                };
3055
3056                let excerpt_buffer_snapshot =
3057                    excerpt_buffer.read_with(cx, |excerpt_buffer, _| excerpt_buffer.snapshot());
3058                let mut ranges = reference
3059                    .excerpts
3060                    .iter()
3061                    .filter(|excerpt| excerpt.buffer == excerpt_buffer)
3062                    .map(|excerpt| excerpt.range.to_point(&excerpt_buffer_snapshot))
3063                    .collect::<Vec<_>>();
3064                mutate_excerpt_ranges(&mut rng, &mut ranges, &excerpt_buffer_snapshot, 1);
3065                let ranges = ranges
3066                    .iter()
3067                    .cloned()
3068                    .map(ExcerptRange::new)
3069                    .collect::<Vec<_>>();
3070                let path = cx.update(|cx| PathKey::for_buffer(&excerpt_buffer, cx));
3071
3072                let (_, path_key_index, _) = multibuffer.update(cx, |multibuffer, cx| {
3073                    multibuffer.set_excerpt_ranges_for_path(
3074                        path.clone(),
3075                        excerpt_buffer.clone(),
3076                        &excerpt_buffer_snapshot,
3077                        ranges.clone(),
3078                        cx,
3079                    )
3080                });
3081
3082                reference.set_excerpts(
3083                    path,
3084                    path_key_index,
3085                    excerpt_buffer.clone(),
3086                    &excerpt_buffer_snapshot,
3087                    ranges,
3088                );
3089
3090                let excerpt_buffer_id =
3091                    excerpt_buffer.read_with(cx, |buffer, _| buffer.remote_id());
3092                multibuffer.update(cx, |multibuffer, cx| {
3093                    if multibuffer.diff_for(excerpt_buffer_id).is_none() {
3094                        if let Some(main_buffer) = inverted_main_buffer {
3095                            reference.add_inverted_diff(diff.clone(), main_buffer.clone(), cx);
3096                            multibuffer.add_inverted_diff(diff, main_buffer, cx);
3097                        } else {
3098                            reference.add_diff(diff.clone(), cx);
3099                            multibuffer.add_diff(diff, cx);
3100                        }
3101                    }
3102                });
3103            }
3104        }
3105
3106        if rng.random_bool(0.3) {
3107            multibuffer.update(cx, |multibuffer, cx| {
3108                old_versions.push((multibuffer.snapshot(cx), multibuffer.subscribe()));
3109            })
3110        }
3111
3112        multibuffer.read_with(cx, |multibuffer, cx| {
3113            check_multibuffer(multibuffer, &reference, &anchors, cx, &mut rng);
3114        });
3115    }
3116    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
3117    for (old_snapshot, subscription) in old_versions {
3118        check_multibuffer_edits(&snapshot, &old_snapshot, subscription);
3119    }
3120}
3121
3122fn mutate_excerpt_ranges(
3123    rng: &mut StdRng,
3124    existing_ranges: &mut Vec<Range<Point>>,
3125    buffer: &BufferSnapshot,
3126    operations: u32,
3127) {
3128    let mut ranges_to_add = Vec::new();
3129
3130    for _ in 0..operations {
3131        // todo!() logging
3132        match rng.random_range(0..5) {
3133            0..=1 if !existing_ranges.is_empty() => {
3134                log::info!("Removing excerpt",);
3135                let index = rng.random_range(0..existing_ranges.len());
3136                existing_ranges.remove(index);
3137            }
3138            _ => {
3139                log::info!("Inserting excerpt",);
3140                let end_row = rng.random_range(0..=buffer.max_point().row);
3141                let start_row = rng.random_range(0..=end_row);
3142                ranges_to_add.push(Point::new(start_row, 0)..Point::new(end_row, 0));
3143            }
3144        }
3145    }
3146
3147    existing_ranges.extend(ranges_to_add);
3148    existing_ranges.sort_by(|l, r| l.start.cmp(&r.start));
3149}
3150
3151fn check_multibuffer(
3152    multibuffer: &MultiBuffer,
3153    reference: &ReferenceMultibuffer,
3154    anchors: &[Anchor],
3155    cx: &App,
3156    rng: &mut StdRng,
3157) {
3158    let snapshot = multibuffer.snapshot(cx);
3159    let actual_text = snapshot.text();
3160    let actual_boundary_rows = snapshot
3161        .excerpt_boundaries_in_range(MultiBufferOffset(0)..)
3162        .map(|b| b.row)
3163        .collect::<HashSet<_>>();
3164    let actual_row_infos = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
3165
3166    let (expected_text, expected_row_infos, expected_boundary_rows) =
3167        reference.expected_content(cx);
3168
3169    let has_diff = actual_row_infos
3170        .iter()
3171        .any(|info| info.diff_status.is_some())
3172        || expected_row_infos
3173            .iter()
3174            .any(|info| info.diff_status.is_some());
3175    let actual_diff = format_diff(
3176        &actual_text,
3177        &actual_row_infos,
3178        &actual_boundary_rows,
3179        Some(has_diff),
3180    );
3181    let expected_diff = format_diff(
3182        &expected_text,
3183        &expected_row_infos,
3184        &expected_boundary_rows,
3185        Some(has_diff),
3186    );
3187
3188    log::info!("Multibuffer content:\n{}", actual_diff);
3189    dbg!(
3190        snapshot
3191            .excerpts()
3192            .map(|(buffer_snapshot, excerpt)| {
3193                (
3194                    buffer_snapshot.remote_id(),
3195                    excerpt.range.to_point(&buffer_snapshot),
3196                )
3197            })
3198            .collect::<Vec<_>>()
3199    );
3200    dbg!(
3201        reference
3202            .excerpts
3203            .iter()
3204            .cloned()
3205            .map(|excerpt| (
3206                excerpt.path_key,
3207                excerpt.range.to_point(&excerpt.buffer.read(cx).snapshot())
3208            ))
3209            .collect::<Vec<_>>()
3210    );
3211
3212    assert_eq!(
3213        actual_row_infos.len(),
3214        actual_text.split('\n').count(),
3215        "line count: {}",
3216        actual_text.split('\n').count()
3217    );
3218    pretty_assertions::assert_eq!(actual_diff, expected_diff);
3219    pretty_assertions::assert_eq!(actual_text, expected_text);
3220    pretty_assertions::assert_eq!(actual_row_infos, expected_row_infos);
3221
3222    for _ in 0..5 {
3223        let start_row = rng.random_range(0..=expected_row_infos.len());
3224        assert_eq!(
3225            snapshot
3226                .row_infos(MultiBufferRow(start_row as u32))
3227                .collect::<Vec<_>>(),
3228            &expected_row_infos[start_row..],
3229            "buffer_rows({})",
3230            start_row
3231        );
3232    }
3233    // dbg!(&expected_row_infos);
3234
3235    // dbg!(
3236    //     snapshot
3237    //         .excerpts()
3238    //         .map(|(buffer_snapshot, excerpt)| {
3239    //             (
3240    //                 buffer_snapshot.remote_id(),
3241    //                 excerpt.range.to_point(&buffer_snapshot),
3242    //             )
3243    //         })
3244    //         .collect::<Vec<_>>()
3245    // );
3246    // dbg!(&expected_row_infos);
3247    // dbg!(
3248    //     reference
3249    //         .excerpts
3250    //         .iter()
3251    //         .map(|excerpt| { excerpt.range.to_point(&excerpt.buffer.read(cx).snapshot()) })
3252    //         .collect::<Vec<_>>()
3253    // );
3254
3255    assert_eq!(
3256        snapshot.widest_line_number(),
3257        expected_row_infos
3258            .into_iter()
3259            .filter_map(|info| {
3260                // For inverted diffs, deleted rows are visible and should be counted.
3261                // Only filter out deleted rows that are NOT from inverted diffs.
3262                let is_inverted_diff = info
3263                    .buffer_id
3264                    .is_some_and(|id| reference.inverted_diffs.contains_key(&id));
3265                if info.diff_status.is_some_and(|status| status.is_deleted()) && !is_inverted_diff {
3266                    None
3267                } else {
3268                    info.buffer_row
3269                }
3270            })
3271            .max()
3272            .unwrap()
3273            + 1
3274    );
3275    // let reference_ranges = reference
3276    //     .excerpts
3277    //     .iter()
3278    //     .map(|excerpt| {
3279    //         (
3280    //             excerpt.info(cx),
3281    //             excerpt.range.to_offset(&excerpt.buffer.read(cx).snapshot()),
3282    //         )
3283    //     })
3284    //     .collect::<Vec<_>>();
3285    for i in 0..snapshot.len().0 {
3286        // todo!() this seems not useful
3287        let excerpt = snapshot
3288            .excerpt_containing(MultiBufferOffset(i)..MultiBufferOffset(i))
3289            .unwrap();
3290        let reference_range = reference
3291            .excerpts
3292            .iter()
3293            .find(|reference_excerpt| reference_excerpt.info(cx) == excerpt.excerpt.info())
3294            .map(|excerpt| excerpt.range.to_offset(&excerpt.buffer.read(cx).snapshot()))
3295            .expect("corresponding excerpt should exist in reference multibuffer");
3296        assert_eq!(
3297            excerpt.buffer_range(&snapshot).start.0..excerpt.buffer_range(&snapshot).end.0,
3298            reference_range
3299        );
3300    }
3301
3302    assert_consistent_line_numbers(&snapshot);
3303    assert_position_translation(&snapshot);
3304
3305    for (row, line) in expected_text.split('\n').enumerate() {
3306        assert_eq!(
3307            snapshot.line_len(MultiBufferRow(row as u32)),
3308            line.len() as u32,
3309            "line_len({}).",
3310            row
3311        );
3312    }
3313
3314    let text_rope = Rope::from(expected_text.as_str());
3315    for _ in 0..10 {
3316        let end_ix = text_rope.clip_offset(rng.random_range(0..=text_rope.len()), Bias::Right);
3317        let start_ix = text_rope.clip_offset(rng.random_range(0..=end_ix), Bias::Left);
3318
3319        let text_for_range = snapshot
3320            .text_for_range(MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix))
3321            .collect::<String>();
3322        assert_eq!(
3323            text_for_range,
3324            &expected_text[start_ix..end_ix],
3325            "incorrect text for range {:?}",
3326            start_ix..end_ix
3327        );
3328
3329        let expected_summary =
3330            MBTextSummary::from(TextSummary::from(&expected_text[start_ix..end_ix]));
3331        assert_eq!(
3332            snapshot.text_summary_for_range::<MBTextSummary, _>(
3333                MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix)
3334            ),
3335            expected_summary,
3336            "incorrect summary for range {:?}",
3337            start_ix..end_ix
3338        );
3339    }
3340
3341    // Anchor resolution
3342    let summaries = snapshot.summaries_for_anchors::<MultiBufferOffset, _>(anchors);
3343    assert_eq!(anchors.len(), summaries.len());
3344    for (anchor, resolved_offset) in anchors.iter().zip(summaries) {
3345        assert!(resolved_offset <= snapshot.len());
3346        assert_eq!(
3347            snapshot.summary_for_anchor::<MultiBufferOffset>(anchor),
3348            resolved_offset,
3349            "anchor: {:?}",
3350            anchor
3351        );
3352    }
3353
3354    for _ in 0..10 {
3355        let end_ix = text_rope.clip_offset(rng.random_range(0..=text_rope.len()), Bias::Right);
3356        assert_eq!(
3357            snapshot
3358                .reversed_chars_at(MultiBufferOffset(end_ix))
3359                .collect::<String>(),
3360            expected_text[..end_ix].chars().rev().collect::<String>(),
3361        );
3362    }
3363
3364    for _ in 0..10 {
3365        let end_ix = rng.random_range(0..=text_rope.len());
3366        let end_ix = text_rope.floor_char_boundary(end_ix);
3367        let start_ix = rng.random_range(0..=end_ix);
3368        let start_ix = text_rope.floor_char_boundary(start_ix);
3369        assert_eq!(
3370            snapshot
3371                .bytes_in_range(MultiBufferOffset(start_ix)..MultiBufferOffset(end_ix))
3372                .flatten()
3373                .copied()
3374                .collect::<Vec<_>>(),
3375            expected_text.as_bytes()[start_ix..end_ix].to_vec(),
3376            "bytes_in_range({:?})",
3377            start_ix..end_ix,
3378        );
3379    }
3380}
3381
3382fn check_multibuffer_edits(
3383    snapshot: &MultiBufferSnapshot,
3384    old_snapshot: &MultiBufferSnapshot,
3385    subscription: Subscription<MultiBufferOffset>,
3386) {
3387    let edits = subscription.consume().into_inner();
3388
3389    log::info!(
3390        "applying subscription edits to old text: {:?}: {:#?}",
3391        old_snapshot.text(),
3392        edits,
3393    );
3394
3395    let mut text = old_snapshot.text();
3396    for edit in edits {
3397        let new_text: String = snapshot
3398            .text_for_range(edit.new.start..edit.new.end)
3399            .collect();
3400        text.replace_range(
3401            (edit.new.start.0..edit.new.start.0 + (edit.old.end.0 - edit.old.start.0)).clone(),
3402            &new_text,
3403        );
3404        pretty_assertions::assert_eq!(
3405            &text[0..edit.new.end.0],
3406            snapshot
3407                .text_for_range(MultiBufferOffset(0)..edit.new.end)
3408                .collect::<String>()
3409        );
3410    }
3411    pretty_assertions::assert_eq!(text, snapshot.text());
3412}
3413
3414#[gpui::test]
3415fn test_history(cx: &mut App) {
3416    let test_settings = SettingsStore::test(cx);
3417    cx.set_global(test_settings);
3418
3419    let group_interval: Duration = Duration::from_millis(1);
3420    let buffer_1 = cx.new(|cx| {
3421        let mut buf = Buffer::local("1234", cx);
3422        buf.set_group_interval(group_interval);
3423        buf
3424    });
3425    let buffer_2 = cx.new(|cx| {
3426        let mut buf = Buffer::local("5678", cx);
3427        buf.set_group_interval(group_interval);
3428        buf
3429    });
3430    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
3431    multibuffer.update(cx, |this, _| {
3432        this.set_group_interval(group_interval);
3433    });
3434    multibuffer.update(cx, |multibuffer, cx| {
3435        multibuffer.set_excerpts_for_path(
3436            PathKey::sorted(0),
3437            buffer_1.clone(),
3438            [Point::zero()..buffer_1.read(cx).max_point()],
3439            0,
3440            cx,
3441        );
3442        multibuffer.set_excerpts_for_path(
3443            PathKey::sorted(1),
3444            buffer_2.clone(),
3445            [Point::zero()..buffer_2.read(cx).max_point()],
3446            0,
3447            cx,
3448        );
3449    });
3450
3451    let mut now = Instant::now();
3452
3453    multibuffer.update(cx, |multibuffer, cx| {
3454        let transaction_1 = multibuffer.start_transaction_at(now, cx).unwrap();
3455        multibuffer.edit(
3456            [
3457                (Point::new(0, 0)..Point::new(0, 0), "A"),
3458                (Point::new(1, 0)..Point::new(1, 0), "A"),
3459            ],
3460            None,
3461            cx,
3462        );
3463        multibuffer.edit(
3464            [
3465                (Point::new(0, 1)..Point::new(0, 1), "B"),
3466                (Point::new(1, 1)..Point::new(1, 1), "B"),
3467            ],
3468            None,
3469            cx,
3470        );
3471        multibuffer.end_transaction_at(now, cx);
3472        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3473
3474        // Verify edited ranges for transaction 1
3475        assert_eq!(
3476            multibuffer.edited_ranges_for_transaction(transaction_1, cx),
3477            &[
3478                MultiBufferOffset(0)..MultiBufferOffset(2),
3479                MultiBufferOffset(7)..MultiBufferOffset(9),
3480            ]
3481        );
3482
3483        // Edit buffer 1 through the multibuffer
3484        now += 2 * group_interval;
3485        multibuffer.start_transaction_at(now, cx);
3486        multibuffer.edit(
3487            [(MultiBufferOffset(2)..MultiBufferOffset(2), "C")],
3488            None,
3489            cx,
3490        );
3491        multibuffer.end_transaction_at(now, cx);
3492        assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3493
3494        // Edit buffer 1 independently
3495        buffer_1.update(cx, |buffer_1, cx| {
3496            buffer_1.start_transaction_at(now);
3497            buffer_1.edit([(3..3, "D")], None, cx);
3498            buffer_1.end_transaction_at(now, cx);
3499
3500            now += 2 * group_interval;
3501            buffer_1.start_transaction_at(now);
3502            buffer_1.edit([(4..4, "E")], None, cx);
3503            buffer_1.end_transaction_at(now, cx);
3504        });
3505        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\nAB5678");
3506
3507        // An undo in the multibuffer undoes the multibuffer transaction
3508        // and also any individual buffer edits that have occurred since
3509        // that transaction.
3510        multibuffer.undo(cx);
3511        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3512
3513        multibuffer.undo(cx);
3514        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3515
3516        multibuffer.redo(cx);
3517        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3518
3519        multibuffer.redo(cx);
3520        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\nAB5678");
3521
3522        // Undo buffer 2 independently.
3523        buffer_2.update(cx, |buffer_2, cx| buffer_2.undo(cx));
3524        assert_eq!(multibuffer.read(cx).text(), "ABCDE1234\n5678");
3525
3526        // An undo in the multibuffer undoes the components of the
3527        // the last multibuffer transaction that are not already undone.
3528        multibuffer.undo(cx);
3529        assert_eq!(multibuffer.read(cx).text(), "AB1234\n5678");
3530
3531        multibuffer.undo(cx);
3532        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3533
3534        multibuffer.redo(cx);
3535        assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3536
3537        buffer_1.update(cx, |buffer_1, cx| buffer_1.redo(cx));
3538        assert_eq!(multibuffer.read(cx).text(), "ABCD1234\nAB5678");
3539
3540        // Redo stack gets cleared after an edit.
3541        now += 2 * group_interval;
3542        multibuffer.start_transaction_at(now, cx);
3543        multibuffer.edit(
3544            [(MultiBufferOffset(0)..MultiBufferOffset(0), "X")],
3545            None,
3546            cx,
3547        );
3548        multibuffer.end_transaction_at(now, cx);
3549        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3550        multibuffer.redo(cx);
3551        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3552        multibuffer.undo(cx);
3553        assert_eq!(multibuffer.read(cx).text(), "ABCD1234\nAB5678");
3554        multibuffer.undo(cx);
3555        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3556
3557        // Transactions can be grouped manually.
3558        multibuffer.redo(cx);
3559        multibuffer.redo(cx);
3560        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3561        multibuffer.group_until_transaction(transaction_1, cx);
3562        multibuffer.undo(cx);
3563        assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3564        multibuffer.redo(cx);
3565        assert_eq!(multibuffer.read(cx).text(), "XABCD1234\nAB5678");
3566    });
3567}
3568
3569#[gpui::test]
3570async fn test_enclosing_indent(cx: &mut TestAppContext) {
3571    async fn enclosing_indent(
3572        text: &str,
3573        buffer_row: u32,
3574        cx: &mut TestAppContext,
3575    ) -> Option<(Range<u32>, LineIndent)> {
3576        let buffer = cx.update(|cx| MultiBuffer::build_simple(text, cx));
3577        let snapshot = cx.read(|cx| buffer.read(cx).snapshot(cx));
3578        let (range, indent) = snapshot
3579            .enclosing_indent(MultiBufferRow(buffer_row))
3580            .await?;
3581        Some((range.start.0..range.end.0, indent))
3582    }
3583
3584    assert_eq!(
3585        enclosing_indent(
3586            indoc!(
3587                "
3588                fn b() {
3589                    if c {
3590                        let d = 2;
3591                    }
3592                }
3593                "
3594            ),
3595            1,
3596            cx,
3597        )
3598        .await,
3599        Some((
3600            1..2,
3601            LineIndent {
3602                tabs: 0,
3603                spaces: 4,
3604                line_blank: false,
3605            }
3606        ))
3607    );
3608
3609    assert_eq!(
3610        enclosing_indent(
3611            indoc!(
3612                "
3613                fn b() {
3614                    if c {
3615                        let d = 2;
3616                    }
3617                }
3618                "
3619            ),
3620            2,
3621            cx,
3622        )
3623        .await,
3624        Some((
3625            1..2,
3626            LineIndent {
3627                tabs: 0,
3628                spaces: 4,
3629                line_blank: false,
3630            }
3631        ))
3632    );
3633
3634    assert_eq!(
3635        enclosing_indent(
3636            indoc!(
3637                "
3638                fn b() {
3639                    if c {
3640                        let d = 2;
3641
3642                        let e = 5;
3643                    }
3644                }
3645                "
3646            ),
3647            3,
3648            cx,
3649        )
3650        .await,
3651        Some((
3652            1..4,
3653            LineIndent {
3654                tabs: 0,
3655                spaces: 4,
3656                line_blank: false,
3657            }
3658        ))
3659    );
3660}
3661
3662#[gpui::test]
3663async fn test_summaries_for_anchors(cx: &mut TestAppContext) {
3664    let base_text_1 = indoc!(
3665        "
3666        bar
3667        "
3668    );
3669    let text_1 = indoc!(
3670        "
3671        BAR
3672        "
3673    );
3674    let base_text_2 = indoc!(
3675        "
3676        foo
3677        "
3678    );
3679    let text_2 = indoc!(
3680        "
3681        FOO
3682        "
3683    );
3684
3685    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
3686    let buffer_2 = cx.new(|cx| Buffer::local(text_2, cx));
3687    let diff_1 = cx.new(|cx| {
3688        BufferDiff::new_with_base_text(base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
3689    });
3690    let diff_2 = cx.new(|cx| {
3691        BufferDiff::new_with_base_text(base_text_2, &buffer_2.read(cx).text_snapshot(), cx)
3692    });
3693    cx.run_until_parked();
3694
3695    let multibuffer = cx.new(|cx| {
3696        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3697        multibuffer.set_all_diff_hunks_expanded(cx);
3698        multibuffer.set_excerpts_for_path(
3699            PathKey::sorted(0),
3700            buffer_1.clone(),
3701            [Point::zero()..buffer_1.read(cx).max_point()],
3702            0,
3703            cx,
3704        );
3705        multibuffer.set_excerpts_for_path(
3706            PathKey::sorted(1),
3707            buffer_2.clone(),
3708            [Point::zero()..buffer_2.read(cx).max_point()],
3709            0,
3710            cx,
3711        );
3712        multibuffer.add_diff(diff_1.clone(), cx);
3713        multibuffer.add_diff(diff_2.clone(), cx);
3714        multibuffer
3715    });
3716
3717    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3718        (multibuffer.snapshot(cx), multibuffer.subscribe())
3719    });
3720
3721    assert_new_snapshot(
3722        &multibuffer,
3723        &mut snapshot,
3724        &mut subscription,
3725        cx,
3726        indoc!(
3727            "
3728            - bar
3729            + BAR
3730
3731            - foo
3732            + FOO
3733            "
3734        ),
3735    );
3736
3737    let anchor_1 = multibuffer.read_with(cx, |multibuffer, cx| {
3738        multibuffer
3739            .buffer_anchor_to_anchor(
3740                &buffer_1,
3741                text::Anchor::min_for_buffer(buffer_1.read(cx).remote_id()),
3742                cx,
3743            )
3744            .unwrap()
3745    });
3746    let point_1 = snapshot.summaries_for_anchors::<Point, _>([&anchor_1])[0];
3747    assert_eq!(point_1, Point::new(0, 0));
3748
3749    let anchor_2 = multibuffer.read_with(cx, |multibuffer, cx| {
3750        multibuffer
3751            .buffer_anchor_to_anchor(
3752                &buffer_2,
3753                text::Anchor::min_for_buffer(buffer_2.read(cx).remote_id()),
3754                cx,
3755            )
3756            .unwrap()
3757    });
3758    let point_2 = snapshot.summaries_for_anchors::<Point, _>([&anchor_2])[0];
3759    assert_eq!(point_2, Point::new(3, 0));
3760}
3761
3762#[gpui::test]
3763async fn test_trailing_deletion_without_newline(cx: &mut TestAppContext) {
3764    let base_text_1 = "one\ntwo".to_owned();
3765    let text_1 = "one\n".to_owned();
3766
3767    let buffer_1 = cx.new(|cx| Buffer::local(text_1, cx));
3768    let diff_1 = cx.new(|cx| {
3769        BufferDiff::new_with_base_text(&base_text_1, &buffer_1.read(cx).text_snapshot(), cx)
3770    });
3771    cx.run_until_parked();
3772
3773    let multibuffer = cx.new(|cx| {
3774        let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3775        multibuffer.set_excerpts_for_path(
3776            PathKey::sorted(0),
3777            buffer_1.clone(),
3778            [Point::zero()..buffer_1.read(cx).max_point()],
3779            0,
3780            cx,
3781        );
3782        multibuffer.add_diff(diff_1.clone(), cx);
3783        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
3784        multibuffer
3785    });
3786
3787    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3788        (multibuffer.snapshot(cx), multibuffer.subscribe())
3789    });
3790
3791    assert_new_snapshot(
3792        &multibuffer,
3793        &mut snapshot,
3794        &mut subscription,
3795        cx,
3796        indoc!(
3797            "
3798              one
3799            - two
3800            "
3801        ),
3802    );
3803
3804    assert_eq!(snapshot.max_point(), Point::new(2, 0));
3805    assert_eq!(snapshot.len().0, 8);
3806
3807    assert_eq!(
3808        snapshot
3809            .dimensions_from_points::<Point>([Point::new(2, 0)])
3810            .collect::<Vec<_>>(),
3811        vec![Point::new(2, 0)]
3812    );
3813
3814    let (_, translated_offset) = snapshot.point_to_buffer_offset(Point::new(2, 0)).unwrap();
3815    assert_eq!(translated_offset.0, "one\n".len());
3816    let (_, translated_point) = snapshot.point_to_buffer_point(Point::new(2, 0)).unwrap();
3817    assert_eq!(translated_point, Point::new(1, 0));
3818
3819    // The same, for an excerpt that's not at the end of the multibuffer.
3820
3821    let text_2 = "foo\n".to_owned();
3822    let buffer_2 = cx.new(|cx| Buffer::local(&text_2, cx));
3823    multibuffer.update(cx, |multibuffer, cx| {
3824        multibuffer.set_excerpt_ranges_for_path(
3825            PathKey::sorted(1),
3826            buffer_2.clone(),
3827            &buffer_2.read(cx).snapshot(),
3828            vec![ExcerptRange::new(Point::new(0, 0)..Point::new(1, 0))],
3829            cx,
3830        );
3831    });
3832
3833    assert_new_snapshot(
3834        &multibuffer,
3835        &mut snapshot,
3836        &mut subscription,
3837        cx,
3838        indoc!(
3839            "
3840              one
3841            - two
3842
3843              foo
3844            "
3845        ),
3846    );
3847
3848    assert_eq!(
3849        snapshot
3850            .dimensions_from_points::<Point>([Point::new(2, 0)])
3851            .collect::<Vec<_>>(),
3852        vec![Point::new(2, 0)]
3853    );
3854
3855    let buffer_1_id = buffer_1.read_with(cx, |buffer_1, _| buffer_1.remote_id());
3856    let (buffer, translated_offset) = snapshot.point_to_buffer_offset(Point::new(2, 0)).unwrap();
3857    assert_eq!(buffer.remote_id(), buffer_1_id);
3858    assert_eq!(translated_offset.0, "one\n".len());
3859    let (buffer, translated_point) = snapshot.point_to_buffer_point(Point::new(2, 0)).unwrap();
3860    assert_eq!(buffer.remote_id(), buffer_1_id);
3861    assert_eq!(translated_point, Point::new(1, 0));
3862}
3863
3864fn format_diff(
3865    text: &str,
3866    row_infos: &Vec<RowInfo>,
3867    boundary_rows: &HashSet<MultiBufferRow>,
3868    has_diff: Option<bool>,
3869) -> String {
3870    let has_diff =
3871        has_diff.unwrap_or_else(|| row_infos.iter().any(|info| info.diff_status.is_some()));
3872    text.split('\n')
3873        .enumerate()
3874        .zip(row_infos)
3875        .map(|((ix, line), info)| {
3876            let marker = match info.diff_status.map(|status| status.kind) {
3877                Some(DiffHunkStatusKind::Added) => "+ ",
3878                Some(DiffHunkStatusKind::Deleted) => "- ",
3879                Some(DiffHunkStatusKind::Modified) => unreachable!(),
3880                None => {
3881                    if has_diff && !line.is_empty() {
3882                        "  "
3883                    } else {
3884                        ""
3885                    }
3886                }
3887            };
3888            let boundary_row = if boundary_rows.contains(&MultiBufferRow(ix as u32)) {
3889                if has_diff {
3890                    "  ----------\n"
3891                } else {
3892                    "---------\n"
3893                }
3894            } else {
3895                ""
3896            };
3897            let expand = info
3898                .expand_info
3899                .as_ref()
3900                .map(|expand_info| match expand_info.direction {
3901                    ExpandExcerptDirection::Up => " [↑]",
3902                    ExpandExcerptDirection::Down => " [↓]",
3903                    ExpandExcerptDirection::UpAndDown => " [↕]",
3904                })
3905                .unwrap_or_default();
3906
3907            format!("{boundary_row}{marker}{line}{expand}")
3908            // let mbr = info
3909            //     .multibuffer_row
3910            //     .map(|row| format!("{:0>3}", row.0))
3911            //     .unwrap_or_else(|| "???".to_string());
3912            // let byte_range = format!("{byte_range_start:0>3}..{byte_range_end:0>3}");
3913            // format!("{boundary_row}Row: {mbr}, Bytes: {byte_range} | {marker}{line}{expand}")
3914        })
3915        .collect::<Vec<_>>()
3916        .join("\n")
3917}
3918
3919// fn format_transforms(snapshot: &MultiBufferSnapshot) -> String {
3920//     snapshot
3921//         .diff_transforms
3922//         .iter()
3923//         .map(|transform| {
3924//             let (kind, summary) = match transform {
3925//                 DiffTransform::DeletedHunk { summary, .. } => ("   Deleted", (*summary).into()),
3926//                 DiffTransform::FilteredInsertedHunk { summary, .. } => ("  Filtered", *summary),
3927//                 DiffTransform::InsertedHunk { summary, .. } => ("  Inserted", *summary),
3928//                 DiffTransform::Unmodified { summary, .. } => ("Unmodified", *summary),
3929//             };
3930//             format!("{kind}(len: {}, lines: {:?})", summary.len, summary.lines)
3931//         })
3932//         .join("\n")
3933// }
3934
3935// fn format_excerpts(snapshot: &MultiBufferSnapshot) -> String {
3936//     snapshot
3937//         .excerpts
3938//         .iter()
3939//         .map(|excerpt| {
3940//             format!(
3941//                 "Excerpt(buffer_range = {:?}, lines = {:?}, has_trailing_newline = {:?})",
3942//                 excerpt.range.context.to_point(&excerpt.buffer),
3943//                 excerpt.text_summary.lines,
3944//                 excerpt.has_trailing_newline
3945//             )
3946//         })
3947//         .join("\n")
3948// }
3949
3950#[gpui::test]
3951async fn test_singleton_with_inverted_diff(cx: &mut TestAppContext) {
3952    let text = indoc!(
3953        "
3954        ZERO
3955        one
3956        TWO
3957        three
3958        six
3959        "
3960    );
3961    let base_text = indoc!(
3962        "
3963        one
3964        two
3965        three
3966        four
3967        five
3968        six
3969        "
3970    );
3971
3972    let buffer = cx.new(|cx| Buffer::local(text, cx));
3973    let diff = cx
3974        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
3975    cx.run_until_parked();
3976
3977    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
3978
3979    let multibuffer = cx.new(|cx| {
3980        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
3981        multibuffer.set_all_diff_hunks_expanded(cx);
3982        multibuffer.add_inverted_diff(diff.clone(), buffer.clone(), cx);
3983        multibuffer
3984    });
3985
3986    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
3987        (multibuffer.snapshot(cx), multibuffer.subscribe())
3988    });
3989
3990    assert_eq!(snapshot.text(), base_text);
3991    assert_new_snapshot(
3992        &multibuffer,
3993        &mut snapshot,
3994        &mut subscription,
3995        cx,
3996        indoc!(
3997            "
3998              one
3999            - two
4000              three
4001            - four
4002            - five
4003              six
4004            "
4005        ),
4006    );
4007
4008    buffer.update(cx, |buffer, cx| {
4009        buffer.edit_via_marked_text(
4010            indoc!(
4011                "
4012                ZERO
4013                one
4014                «<inserted>»W«O
4015                T»hree
4016                six
4017                "
4018            ),
4019            None,
4020            cx,
4021        );
4022    });
4023    cx.run_until_parked();
4024    let update = diff
4025        .update(cx, |diff, cx| {
4026            diff.update_diff(
4027                buffer.read(cx).text_snapshot(),
4028                Some(base_text.into()),
4029                None,
4030                None,
4031                cx,
4032            )
4033        })
4034        .await;
4035    diff.update(cx, |diff, cx| {
4036        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4037    })
4038    .await;
4039    cx.run_until_parked();
4040
4041    assert_new_snapshot(
4042        &multibuffer,
4043        &mut snapshot,
4044        &mut subscription,
4045        cx,
4046        indoc! {
4047            "
4048              one
4049            - two
4050            - three
4051            - four
4052            - five
4053              six
4054            "
4055        },
4056    );
4057
4058    buffer.update(cx, |buffer, cx| {
4059        buffer.set_text("ZERO\nONE\nTWO\n", cx);
4060    });
4061    cx.run_until_parked();
4062    let update = diff
4063        .update(cx, |diff, cx| {
4064            diff.update_diff(
4065                buffer.read(cx).text_snapshot(),
4066                Some(base_text.into()),
4067                None,
4068                None,
4069                cx,
4070            )
4071        })
4072        .await;
4073    diff.update(cx, |diff, cx| {
4074        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4075    })
4076    .await;
4077    cx.run_until_parked();
4078
4079    assert_new_snapshot(
4080        &multibuffer,
4081        &mut snapshot,
4082        &mut subscription,
4083        cx,
4084        indoc! {
4085            "
4086            - one
4087            - two
4088            - three
4089            - four
4090            - five
4091            - six
4092            "
4093        },
4094    );
4095
4096    diff.update(cx, |diff, cx| {
4097        diff.set_base_text(
4098            Some("new base\n".into()),
4099            None,
4100            buffer.read(cx).text_snapshot(),
4101            cx,
4102        )
4103    })
4104    .await
4105    .unwrap();
4106    cx.run_until_parked();
4107
4108    assert_new_snapshot(
4109        &multibuffer,
4110        &mut snapshot,
4111        &mut subscription,
4112        cx,
4113        indoc! {"
4114            - new base
4115        "},
4116    );
4117}
4118
4119#[gpui::test]
4120async fn test_inverted_diff_base_text_change(cx: &mut TestAppContext) {
4121    let base_text = "aaa\nbbb\nccc\n";
4122    let text = "ddd\n";
4123    let buffer = cx.new(|cx| Buffer::local(text, cx));
4124    let diff = cx
4125        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
4126    cx.run_until_parked();
4127
4128    let base_text_buffer = diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
4129
4130    let multibuffer = cx.new(|cx| {
4131        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
4132        multibuffer.set_all_diff_hunks_expanded(cx);
4133        multibuffer.add_inverted_diff(diff.clone(), buffer.clone(), cx);
4134        multibuffer
4135    });
4136
4137    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
4138        (multibuffer.snapshot(cx), multibuffer.subscribe())
4139    });
4140
4141    assert_eq!(snapshot.text(), base_text);
4142    assert_new_snapshot(
4143        &multibuffer,
4144        &mut snapshot,
4145        &mut subscription,
4146        cx,
4147        indoc!(
4148            "
4149            - aaa
4150            - bbb
4151            - ccc
4152            "
4153        ),
4154    );
4155
4156    let update = diff
4157        .update(cx, |diff, cx| {
4158            diff.update_diff(
4159                buffer.read(cx).text_snapshot(),
4160                Some("ddd\n".into()),
4161                Some(true),
4162                None,
4163                cx,
4164            )
4165        })
4166        .await;
4167    diff.update(cx, |diff, cx| {
4168        diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4169    })
4170    .detach();
4171
4172    let _hunks: Vec<_> = multibuffer
4173        .read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx))
4174        .diff_hunks()
4175        .collect();
4176}
4177
4178#[gpui::test]
4179async fn test_inverted_diff_secondary_version_mismatch(cx: &mut TestAppContext) {
4180    let base_text = "one\ntwo\nthree\nfour\nfive\n";
4181    let index_text = "one\nTWO\nthree\nfour\nfive\n";
4182    let buffer_text = "one\nTWO\nthree\nFOUR\nfive\n";
4183
4184    let buffer = cx.new(|cx| Buffer::local(buffer_text, cx));
4185
4186    let unstaged_diff = cx
4187        .new(|cx| BufferDiff::new_with_base_text(index_text, &buffer.read(cx).text_snapshot(), cx));
4188    cx.run_until_parked();
4189
4190    let uncommitted_diff = cx.new(|cx| {
4191        let mut diff =
4192            BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx);
4193        diff.set_secondary_diff(unstaged_diff.clone());
4194        diff
4195    });
4196    cx.run_until_parked();
4197
4198    buffer.update(cx, |buffer, cx| {
4199        buffer.edit([(0..0, "ZERO\n")], None, cx);
4200    });
4201
4202    let update = unstaged_diff
4203        .update(cx, |diff, cx| {
4204            diff.update_diff(
4205                buffer.read(cx).text_snapshot(),
4206                Some(index_text.into()),
4207                None,
4208                None,
4209                cx,
4210            )
4211        })
4212        .await;
4213    unstaged_diff
4214        .update(cx, |diff, cx| {
4215            diff.set_snapshot(update, &buffer.read(cx).text_snapshot(), cx)
4216        })
4217        .await;
4218
4219    let base_text_buffer =
4220        uncommitted_diff.read_with(cx, |diff, _| diff.base_text_buffer().clone());
4221
4222    let multibuffer = cx.new(|cx| {
4223        let mut multibuffer = MultiBuffer::singleton(base_text_buffer.clone(), cx);
4224        multibuffer.set_all_diff_hunks_expanded(cx);
4225        multibuffer.add_inverted_diff(uncommitted_diff.clone(), buffer.clone(), cx);
4226        multibuffer
4227    });
4228
4229    let _hunks: Vec<_> = multibuffer
4230        .read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx))
4231        .diff_hunks()
4232        .collect();
4233}
4234
4235#[track_caller]
4236fn assert_excerpts_match(
4237    multibuffer: &Entity<MultiBuffer>,
4238    cx: &mut TestAppContext,
4239    expected: &str,
4240) {
4241    let mut output = String::new();
4242    multibuffer.read_with(cx, |multibuffer, cx| {
4243        for (buffer, info) in multibuffer.snapshot(cx).excerpts() {
4244            output.push_str("-----\n");
4245            output.extend(buffer.text_for_range(info.range));
4246            if !output.ends_with('\n') {
4247                output.push('\n');
4248            }
4249        }
4250    });
4251    assert_eq!(output, expected);
4252}
4253
4254#[track_caller]
4255fn assert_new_snapshot(
4256    multibuffer: &Entity<MultiBuffer>,
4257    snapshot: &mut MultiBufferSnapshot,
4258    subscription: &mut Subscription<MultiBufferOffset>,
4259    cx: &mut TestAppContext,
4260    expected_diff: &str,
4261) {
4262    let new_snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
4263    let actual_text = new_snapshot.text();
4264    let line_infos = new_snapshot
4265        .row_infos(MultiBufferRow(0))
4266        .collect::<Vec<_>>();
4267    let actual_diff = format_diff(&actual_text, &line_infos, &Default::default(), None);
4268    pretty_assertions::assert_eq!(actual_diff, expected_diff);
4269    check_edits(
4270        snapshot,
4271        &new_snapshot,
4272        &subscription.consume().into_inner(),
4273    );
4274    *snapshot = new_snapshot;
4275}
4276
4277#[track_caller]
4278fn check_edits(
4279    old_snapshot: &MultiBufferSnapshot,
4280    new_snapshot: &MultiBufferSnapshot,
4281    edits: &[Edit<MultiBufferOffset>],
4282) {
4283    let mut text = old_snapshot.text();
4284    let new_text = new_snapshot.text();
4285    for edit in edits.iter().rev() {
4286        if !text.is_char_boundary(edit.old.start.0)
4287            || !text.is_char_boundary(edit.old.end.0)
4288            || !new_text.is_char_boundary(edit.new.start.0)
4289            || !new_text.is_char_boundary(edit.new.end.0)
4290        {
4291            panic!(
4292                "invalid edits: {:?}\nold text: {:?}\nnew text: {:?}",
4293                edits, text, new_text
4294            );
4295        }
4296
4297        text.replace_range(
4298            edit.old.start.0..edit.old.end.0,
4299            &new_text[edit.new.start.0..edit.new.end.0],
4300        );
4301    }
4302
4303    pretty_assertions::assert_eq!(text, new_text, "invalid edits: {:?}", edits);
4304}
4305
4306#[track_caller]
4307fn assert_chunks_in_ranges(snapshot: &MultiBufferSnapshot) {
4308    let full_text = snapshot.text();
4309    for ix in 0..full_text.len() {
4310        let mut chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4311        chunks.seek(MultiBufferOffset(ix)..snapshot.len());
4312        let tail = chunks.map(|chunk| chunk.text).collect::<String>();
4313        assert_eq!(tail, &full_text[ix..], "seek to range: {:?}", ix..);
4314    }
4315}
4316
4317#[track_caller]
4318fn assert_consistent_line_numbers(snapshot: &MultiBufferSnapshot) {
4319    let all_line_numbers = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
4320    for start_row in 1..all_line_numbers.len() {
4321        let line_numbers = snapshot
4322            .row_infos(MultiBufferRow(start_row as u32))
4323            .collect::<Vec<_>>();
4324        assert_eq!(
4325            line_numbers,
4326            all_line_numbers[start_row..],
4327            "start_row: {start_row}"
4328        );
4329    }
4330}
4331
4332#[track_caller]
4333fn assert_position_translation(snapshot: &MultiBufferSnapshot) {
4334    let text = Rope::from(snapshot.text());
4335
4336    let mut left_anchors = Vec::new();
4337    let mut right_anchors = Vec::new();
4338    let mut offsets = Vec::new();
4339    let mut points = Vec::new();
4340    for offset in 0..=text.len() + 1 {
4341        let offset = MultiBufferOffset(offset);
4342        let clipped_left = snapshot.clip_offset(offset, Bias::Left);
4343        let clipped_right = snapshot.clip_offset(offset, Bias::Right);
4344        assert_eq!(
4345            clipped_left.0,
4346            text.clip_offset(offset.0, Bias::Left),
4347            "clip_offset({offset:?}, Left)"
4348        );
4349        assert_eq!(
4350            clipped_right.0,
4351            text.clip_offset(offset.0, Bias::Right),
4352            "clip_offset({offset:?}, Right)"
4353        );
4354        assert_eq!(
4355            snapshot.offset_to_point(clipped_left),
4356            text.offset_to_point(clipped_left.0),
4357            "offset_to_point({})",
4358            clipped_left.0
4359        );
4360        assert_eq!(
4361            snapshot.offset_to_point(clipped_right),
4362            text.offset_to_point(clipped_right.0),
4363            "offset_to_point({})",
4364            clipped_right.0
4365        );
4366        let anchor_after = snapshot.anchor_after(clipped_left);
4367        assert_eq!(
4368            anchor_after.to_offset(snapshot),
4369            clipped_left,
4370            "anchor_after({}).to_offset {anchor_after:?}",
4371            clipped_left.0
4372        );
4373        let anchor_before = snapshot.anchor_before(clipped_left);
4374        assert_eq!(
4375            anchor_before.to_offset(snapshot),
4376            clipped_left,
4377            "anchor_before({}).to_offset",
4378            clipped_left.0
4379        );
4380        left_anchors.push(anchor_before);
4381        right_anchors.push(anchor_after);
4382        offsets.push(clipped_left);
4383        points.push(text.offset_to_point(clipped_left.0));
4384    }
4385
4386    for row in 0..text.max_point().row {
4387        for column in 0..text.line_len(row) + 1 {
4388            let point = Point { row, column };
4389            let clipped_left = snapshot.clip_point(point, Bias::Left);
4390            let clipped_right = snapshot.clip_point(point, Bias::Right);
4391            assert_eq!(
4392                clipped_left,
4393                text.clip_point(point, Bias::Left),
4394                "clip_point({point:?}, Left)"
4395            );
4396            assert_eq!(
4397                clipped_right,
4398                text.clip_point(point, Bias::Right),
4399                "clip_point({point:?}, Right)"
4400            );
4401            assert_eq!(
4402                snapshot.point_to_offset(clipped_left).0,
4403                text.point_to_offset(clipped_left),
4404                "point_to_offset({clipped_left:?})"
4405            );
4406            assert_eq!(
4407                snapshot.point_to_offset(clipped_right).0,
4408                text.point_to_offset(clipped_right),
4409                "point_to_offset({clipped_right:?})"
4410            );
4411        }
4412    }
4413
4414    assert_eq!(
4415        snapshot.summaries_for_anchors::<MultiBufferOffset, _>(&left_anchors),
4416        offsets,
4417        "left_anchors <-> offsets"
4418    );
4419    assert_eq!(
4420        snapshot.summaries_for_anchors::<Point, _>(&left_anchors),
4421        points,
4422        "left_anchors <-> points"
4423    );
4424    assert_eq!(
4425        snapshot.summaries_for_anchors::<MultiBufferOffset, _>(&right_anchors),
4426        offsets,
4427        "right_anchors <-> offsets"
4428    );
4429    assert_eq!(
4430        snapshot.summaries_for_anchors::<Point, _>(&right_anchors),
4431        points,
4432        "right_anchors <-> points"
4433    );
4434
4435    for (anchors, bias) in [(&left_anchors, Bias::Left), (&right_anchors, Bias::Right)] {
4436        for (ix, (offset, anchor)) in offsets.iter().zip(anchors).enumerate() {
4437            if ix > 0 && *offset == MultiBufferOffset(252) && offset > &offsets[ix - 1] {
4438                let prev_anchor = left_anchors[ix - 1];
4439                assert!(
4440                    anchor.cmp(&prev_anchor, snapshot).is_gt(),
4441                    "anchor({}, {bias:?}).cmp(&anchor({}, {bias:?}).is_gt()",
4442                    offsets[ix],
4443                    offsets[ix - 1],
4444                );
4445                assert!(
4446                    prev_anchor.cmp(anchor, snapshot).is_lt(),
4447                    "anchor({}, {bias:?}).cmp(&anchor({}, {bias:?}).is_lt()",
4448                    offsets[ix - 1],
4449                    offsets[ix],
4450                );
4451            }
4452        }
4453    }
4454
4455    if let Some((buffer, offset)) = snapshot.point_to_buffer_offset(snapshot.max_point()) {
4456        assert!(offset.0 <= buffer.len());
4457    }
4458    if let Some((buffer, point)) = snapshot.point_to_buffer_point(snapshot.max_point()) {
4459        assert!(point <= buffer.max_point());
4460    }
4461}
4462
4463fn assert_line_indents(snapshot: &MultiBufferSnapshot) {
4464    let max_row = snapshot.max_point().row;
4465    let buffer_id = snapshot.excerpts().next().unwrap().1.buffer_id;
4466    let text = text::Buffer::new(ReplicaId::LOCAL, buffer_id, snapshot.text());
4467    let mut line_indents = text
4468        .line_indents_in_row_range(0..max_row + 1)
4469        .collect::<Vec<_>>();
4470    for start_row in 0..snapshot.max_point().row {
4471        pretty_assertions::assert_eq!(
4472            snapshot
4473                .line_indents(MultiBufferRow(start_row), |_| true)
4474                .map(|(row, indent, _)| (row.0, indent))
4475                .collect::<Vec<_>>(),
4476            &line_indents[(start_row as usize)..],
4477            "line_indents({start_row})"
4478        );
4479    }
4480
4481    line_indents.reverse();
4482    pretty_assertions::assert_eq!(
4483        snapshot
4484            .reversed_line_indents(MultiBufferRow(max_row), |_| true)
4485            .map(|(row, indent, _)| (row.0, indent))
4486            .collect::<Vec<_>>(),
4487        &line_indents[..],
4488        "reversed_line_indents({max_row})"
4489    );
4490}
4491
4492#[gpui::test]
4493fn test_new_empty_buffer_uses_untitled_title(cx: &mut App) {
4494    let buffer = cx.new(|cx| Buffer::local("", cx));
4495    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4496
4497    assert_eq!(multibuffer.read(cx).title(cx), "untitled");
4498}
4499
4500#[gpui::test]
4501fn test_new_empty_buffer_uses_untitled_title_when_only_contains_whitespace(cx: &mut App) {
4502    let buffer = cx.new(|cx| Buffer::local("\n ", cx));
4503    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4504
4505    assert_eq!(multibuffer.read(cx).title(cx), "untitled");
4506}
4507
4508#[gpui::test]
4509fn test_new_empty_buffer_takes_first_line_for_title(cx: &mut App) {
4510    let buffer = cx.new(|cx| Buffer::local("Hello World\nSecond line", cx));
4511    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4512
4513    assert_eq!(multibuffer.read(cx).title(cx), "Hello World");
4514}
4515
4516#[gpui::test]
4517fn test_new_empty_buffer_takes_trimmed_first_line_for_title(cx: &mut App) {
4518    let buffer = cx.new(|cx| Buffer::local("\nHello, World ", cx));
4519    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4520
4521    assert_eq!(multibuffer.read(cx).title(cx), "Hello, World");
4522}
4523
4524#[gpui::test]
4525fn test_new_empty_buffer_uses_truncated_first_line_for_title(cx: &mut App) {
4526    let title = "aaaaaaaaaabbbbbbbbbbccccccccccddddddddddeeeeeeeeee";
4527    let title_after = "aaaaaaaaaabbbbbbbbbbccccccccccdddddddddd";
4528    let buffer = cx.new(|cx| Buffer::local(title, cx));
4529    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4530
4531    assert_eq!(multibuffer.read(cx).title(cx), title_after);
4532}
4533
4534#[gpui::test]
4535fn test_new_empty_buffer_uses_truncated_first_line_for_title_after_merging_adjacent_spaces(
4536    cx: &mut App,
4537) {
4538    let title = "aaaaaaaaaabbbbbbbbbb    ccccccccccddddddddddeeeeeeeeee";
4539    let title_after = "aaaaaaaaaabbbbbbbbbb ccccccccccddddddddd";
4540    let buffer = cx.new(|cx| Buffer::local(title, cx));
4541    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4542
4543    assert_eq!(multibuffer.read(cx).title(cx), title_after);
4544}
4545
4546#[gpui::test]
4547fn test_new_empty_buffers_title_can_be_set(cx: &mut App) {
4548    let buffer = cx.new(|cx| Buffer::local("Hello World", cx));
4549    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
4550    assert_eq!(multibuffer.read(cx).title(cx), "Hello World");
4551
4552    multibuffer.update(cx, |multibuffer, cx| {
4553        multibuffer.set_title("Hey".into(), cx)
4554    });
4555    assert_eq!(multibuffer.read(cx).title(cx), "Hey");
4556}
4557
4558#[gpui::test(iterations = 100)]
4559fn test_random_chunk_bitmaps(cx: &mut App, mut rng: StdRng) {
4560    let multibuffer = if rng.random() {
4561        let len = rng.random_range(0..10000);
4562        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
4563        let buffer = cx.new(|cx| Buffer::local(text, cx));
4564        cx.new(|cx| MultiBuffer::singleton(buffer, cx))
4565    } else {
4566        MultiBuffer::build_random(&mut rng, cx)
4567    };
4568
4569    let snapshot = multibuffer.read(cx).snapshot(cx);
4570
4571    let chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4572
4573    for chunk in chunks {
4574        let chunk_text = chunk.text;
4575        let chars_bitmap = chunk.chars;
4576        let tabs_bitmap = chunk.tabs;
4577
4578        if chunk_text.is_empty() {
4579            assert_eq!(
4580                chars_bitmap, 0,
4581                "Empty chunk should have empty chars bitmap"
4582            );
4583            assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
4584            continue;
4585        }
4586
4587        assert!(
4588            chunk_text.len() <= 128,
4589            "Chunk text length {} exceeds 128 bytes",
4590            chunk_text.len()
4591        );
4592
4593        // Verify chars bitmap
4594        let char_indices = chunk_text
4595            .char_indices()
4596            .map(|(i, _)| i)
4597            .collect::<Vec<_>>();
4598
4599        for byte_idx in 0..chunk_text.len() {
4600            let should_have_bit = char_indices.contains(&byte_idx);
4601            let has_bit = chars_bitmap & (1 << byte_idx) != 0;
4602
4603            if has_bit != should_have_bit {
4604                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4605                eprintln!("Char indices: {:?}", char_indices);
4606                eprintln!("Chars bitmap: {:#b}", chars_bitmap);
4607            }
4608
4609            assert_eq!(
4610                has_bit, should_have_bit,
4611                "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
4612                byte_idx, chunk_text, should_have_bit, has_bit
4613            );
4614        }
4615
4616        for (byte_idx, byte) in chunk_text.bytes().enumerate() {
4617            let is_tab = byte == b'\t';
4618            let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
4619
4620            if has_bit != is_tab {
4621                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4622                eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
4623                assert_eq!(
4624                    has_bit, is_tab,
4625                    "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
4626                    byte_idx, chunk_text, byte as char, is_tab, has_bit
4627                );
4628            }
4629        }
4630    }
4631}
4632
4633#[gpui::test(iterations = 10)]
4634fn test_random_chunk_bitmaps_with_diffs(cx: &mut App, mut rng: StdRng) {
4635    let settings_store = SettingsStore::test(cx);
4636    cx.set_global(settings_store);
4637    use buffer_diff::BufferDiff;
4638    use util::RandomCharIter;
4639
4640    let multibuffer = if rng.random() {
4641        let len = rng.random_range(100..10000);
4642        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
4643        let buffer = cx.new(|cx| Buffer::local(text, cx));
4644        cx.new(|cx| MultiBuffer::singleton(buffer, cx))
4645    } else {
4646        MultiBuffer::build_random(&mut rng, cx)
4647    };
4648
4649    let _diff_count = rng.random_range(1..5);
4650    let mut diffs = Vec::new();
4651
4652    multibuffer.update(cx, |multibuffer, cx| {
4653        for buffer_id in multibuffer.all_buffer_ids() {
4654            if rng.random_bool(0.7) {
4655                if let Some(buffer_handle) = multibuffer.buffer(buffer_id) {
4656                    let buffer_text = buffer_handle.read(cx).text();
4657                    let mut base_text = String::new();
4658
4659                    for line in buffer_text.lines() {
4660                        if rng.random_bool(0.3) {
4661                            continue;
4662                        } else if rng.random_bool(0.3) {
4663                            let line_len = rng.random_range(0..50);
4664                            let modified_line = RandomCharIter::new(&mut rng)
4665                                .take(line_len)
4666                                .collect::<String>();
4667                            base_text.push_str(&modified_line);
4668                            base_text.push('\n');
4669                        } else {
4670                            base_text.push_str(line);
4671                            base_text.push('\n');
4672                        }
4673                    }
4674
4675                    if rng.random_bool(0.5) {
4676                        let extra_lines = rng.random_range(1..5);
4677                        for _ in 0..extra_lines {
4678                            let line_len = rng.random_range(0..50);
4679                            let extra_line = RandomCharIter::new(&mut rng)
4680                                .take(line_len)
4681                                .collect::<String>();
4682                            base_text.push_str(&extra_line);
4683                            base_text.push('\n');
4684                        }
4685                    }
4686
4687                    let diff = cx.new(|cx| {
4688                        BufferDiff::new_with_base_text(
4689                            &base_text,
4690                            &buffer_handle.read(cx).text_snapshot(),
4691                            cx,
4692                        )
4693                    });
4694                    diffs.push(diff.clone());
4695                    multibuffer.add_diff(diff, cx);
4696                }
4697            }
4698        }
4699    });
4700
4701    multibuffer.update(cx, |multibuffer, cx| {
4702        if rng.random_bool(0.5) {
4703            multibuffer.set_all_diff_hunks_expanded(cx);
4704        } else {
4705            let snapshot = multibuffer.snapshot(cx);
4706            let text = snapshot.text();
4707
4708            let mut ranges = Vec::new();
4709            for _ in 0..rng.random_range(1..5) {
4710                if snapshot.len().0 == 0 {
4711                    break;
4712                }
4713
4714                let diff_size = rng.random_range(5..1000);
4715                let mut start = rng.random_range(0..snapshot.len().0);
4716
4717                while !text.is_char_boundary(start) {
4718                    start = start.saturating_sub(1);
4719                }
4720
4721                let mut end = rng.random_range(start..snapshot.len().0.min(start + diff_size));
4722
4723                while !text.is_char_boundary(end) {
4724                    end = end.saturating_add(1);
4725                }
4726                let start_anchor = snapshot.anchor_after(MultiBufferOffset(start));
4727                let end_anchor = snapshot.anchor_before(MultiBufferOffset(end));
4728                ranges.push(start_anchor..end_anchor);
4729            }
4730            multibuffer.expand_diff_hunks(ranges, cx);
4731        }
4732    });
4733
4734    let snapshot = multibuffer.read(cx).snapshot(cx);
4735
4736    let chunks = snapshot.chunks(MultiBufferOffset(0)..snapshot.len(), false);
4737
4738    for chunk in chunks {
4739        let chunk_text = chunk.text;
4740        let chars_bitmap = chunk.chars;
4741        let tabs_bitmap = chunk.tabs;
4742
4743        if chunk_text.is_empty() {
4744            assert_eq!(
4745                chars_bitmap, 0,
4746                "Empty chunk should have empty chars bitmap"
4747            );
4748            assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
4749            continue;
4750        }
4751
4752        assert!(
4753            chunk_text.len() <= 128,
4754            "Chunk text length {} exceeds 128 bytes",
4755            chunk_text.len()
4756        );
4757
4758        let char_indices = chunk_text
4759            .char_indices()
4760            .map(|(i, _)| i)
4761            .collect::<Vec<_>>();
4762
4763        for byte_idx in 0..chunk_text.len() {
4764            let should_have_bit = char_indices.contains(&byte_idx);
4765            let has_bit = chars_bitmap & (1 << byte_idx) != 0;
4766
4767            if has_bit != should_have_bit {
4768                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4769                eprintln!("Char indices: {:?}", char_indices);
4770                eprintln!("Chars bitmap: {:#b}", chars_bitmap);
4771            }
4772
4773            assert_eq!(
4774                has_bit, should_have_bit,
4775                "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
4776                byte_idx, chunk_text, should_have_bit, has_bit
4777            );
4778        }
4779
4780        for (byte_idx, byte) in chunk_text.bytes().enumerate() {
4781            let is_tab = byte == b'\t';
4782            let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
4783
4784            if has_bit != is_tab {
4785                eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
4786                eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
4787                assert_eq!(
4788                    has_bit, is_tab,
4789                    "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
4790                    byte_idx, chunk_text, byte as char, is_tab, has_bit
4791                );
4792            }
4793        }
4794    }
4795}
4796
4797fn collect_word_diffs(
4798    base_text: &str,
4799    modified_text: &str,
4800    cx: &mut TestAppContext,
4801) -> Vec<String> {
4802    let buffer = cx.new(|cx| Buffer::local(modified_text, cx));
4803    let diff = cx
4804        .new(|cx| BufferDiff::new_with_base_text(base_text, &buffer.read(cx).text_snapshot(), cx));
4805    cx.run_until_parked();
4806
4807    let multibuffer = cx.new(|cx| {
4808        let mut multibuffer = MultiBuffer::singleton(buffer.clone(), cx);
4809        multibuffer.add_diff(diff.clone(), cx);
4810        multibuffer
4811    });
4812
4813    multibuffer.update(cx, |multibuffer, cx| {
4814        multibuffer.expand_diff_hunks(vec![Anchor::min()..Anchor::max()], cx);
4815    });
4816
4817    let snapshot = multibuffer.read_with(cx, |multibuffer, cx| multibuffer.snapshot(cx));
4818    let text = snapshot.text();
4819
4820    snapshot
4821        .diff_hunks()
4822        .flat_map(|hunk| hunk.word_diffs)
4823        .map(|range| text[range.start.0..range.end.0].to_string())
4824        .collect()
4825}
4826
4827#[gpui::test]
4828async fn test_word_diff_simple_replacement(cx: &mut TestAppContext) {
4829    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4830    cx.set_global(settings_store);
4831
4832    let base_text = "hello world foo bar\n";
4833    let modified_text = "hello WORLD foo BAR\n";
4834
4835    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4836
4837    assert_eq!(word_diffs, vec!["world", "bar", "WORLD", "BAR"]);
4838}
4839
4840#[gpui::test]
4841async fn test_word_diff_white_space(cx: &mut TestAppContext) {
4842    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4843    cx.set_global(settings_store);
4844
4845    let base_text = "hello world foo bar\n";
4846    let modified_text = "    hello world foo bar\n";
4847
4848    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4849
4850    assert_eq!(word_diffs, vec!["    "]);
4851}
4852
4853#[gpui::test]
4854async fn test_word_diff_consecutive_modified_lines(cx: &mut TestAppContext) {
4855    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4856    cx.set_global(settings_store);
4857
4858    let base_text = "aaa bbb\nccc ddd\n";
4859    let modified_text = "aaa BBB\nccc DDD\n";
4860
4861    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4862
4863    assert_eq!(
4864        word_diffs,
4865        vec!["bbb", "ddd", "BBB", "DDD"],
4866        "consecutive modified lines should produce word diffs when line counts match"
4867    );
4868}
4869
4870#[gpui::test]
4871async fn test_word_diff_modified_lines_with_deletion_between(cx: &mut TestAppContext) {
4872    let settings_store = cx.update(|cx| SettingsStore::test(cx));
4873    cx.set_global(settings_store);
4874
4875    let base_text = "aaa bbb\ndeleted line\nccc ddd\n";
4876    let modified_text = "aaa BBB\nccc DDD\n";
4877
4878    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4879
4880    assert_eq!(
4881        word_diffs,
4882        Vec::<String>::new(),
4883        "modified lines with a deleted line between should not produce word diffs"
4884    );
4885}
4886
4887#[gpui::test]
4888async fn test_word_diff_disabled(cx: &mut TestAppContext) {
4889    let settings_store = cx.update(|cx| {
4890        let mut settings_store = SettingsStore::test(cx);
4891        settings_store.update_user_settings(cx, |settings| {
4892            settings.project.all_languages.defaults.word_diff_enabled = Some(false);
4893        });
4894        settings_store
4895    });
4896    cx.set_global(settings_store);
4897
4898    let base_text = "hello world\n";
4899    let modified_text = "hello WORLD\n";
4900
4901    let word_diffs = collect_word_diffs(base_text, modified_text, cx);
4902
4903    assert_eq!(
4904        word_diffs,
4905        Vec::<String>::new(),
4906        "word diffs should be empty when disabled"
4907    );
4908}
4909
4910/// Tests `excerpt_containing` and `excerpts_for_range` (functions mapping multi-buffer text-coordinates to excerpts)
4911#[gpui::test]
4912fn test_excerpts_containment_functions(cx: &mut App) {
4913    // Multibuffer content for these tests:
4914    //    0123
4915    // 0: aa0
4916    // 1: aa1
4917    //    -----
4918    // 2: bb0
4919    // 3: bb1
4920    //    -----MultiBufferOffset(0)..
4921    // 4: cc0
4922
4923    let buffer_1 = cx.new(|cx| Buffer::local("aa0\naa1", cx));
4924    let buffer_2 = cx.new(|cx| Buffer::local("bb0\nbb1", cx));
4925    let buffer_3 = cx.new(|cx| Buffer::local("cc0", cx));
4926
4927    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
4928
4929    let (excerpt_1_info, excerpt_2_info, excerpt_3_info) =
4930        multibuffer.update(cx, |multibuffer, cx| {
4931            multibuffer.set_excerpts_for_path(
4932                PathKey::sorted(0),
4933                buffer_1.clone(),
4934                [Point::new(0, 0)..Point::new(1, 3)],
4935                0,
4936                cx,
4937            );
4938
4939            multibuffer.set_excerpts_for_path(
4940                PathKey::sorted(1),
4941                buffer_2.clone(),
4942                [Point::new(0, 0)..Point::new(1, 3)],
4943                0,
4944                cx,
4945            );
4946
4947            multibuffer.set_excerpts_for_path(
4948                PathKey::sorted(2),
4949                buffer_3.clone(),
4950                [Point::new(0, 0)..Point::new(0, 3)],
4951                0,
4952                cx,
4953            );
4954
4955            let snapshot = multibuffer.snapshot(cx);
4956            let mut infos = snapshot.excerpts().map(|(_, info)| info);
4957            (
4958                infos.next().unwrap(),
4959                infos.next().unwrap(),
4960                infos.next().unwrap(),
4961            )
4962        });
4963
4964    let snapshot = multibuffer.read(cx).snapshot(cx);
4965
4966    assert_eq!(snapshot.text(), "aa0\naa1\nbb0\nbb1\ncc0");
4967
4968    //// Test `excerpts_for_range`
4969
4970    let p00 = snapshot.point_to_offset(Point::new(0, 0));
4971    let p10 = snapshot.point_to_offset(Point::new(1, 0));
4972    let p20 = snapshot.point_to_offset(Point::new(2, 0));
4973    let p23 = snapshot.point_to_offset(Point::new(2, 3));
4974    let p13 = snapshot.point_to_offset(Point::new(1, 3));
4975    let p40 = snapshot.point_to_offset(Point::new(4, 0));
4976    let p43 = snapshot.point_to_offset(Point::new(4, 3));
4977
4978    let excerpts: Vec<_> = snapshot.excerpts_for_range(p00..p00).collect();
4979    assert_eq!(excerpts.len(), 1);
4980    assert_eq!(excerpts[0].info(), excerpt_1_info);
4981
4982    // Cursor at very end of excerpt 3
4983    let excerpts: Vec<_> = snapshot.excerpts_for_range(p43..p43).collect();
4984    assert_eq!(excerpts.len(), 1);
4985    assert_eq!(excerpts[0].info(), excerpt_3_info);
4986
4987    let excerpts: Vec<_> = snapshot.excerpts_for_range(p00..p23).collect();
4988    assert_eq!(excerpts.len(), 2);
4989    assert_eq!(excerpts[0].info(), excerpt_1_info);
4990    assert_eq!(excerpts[1].info(), excerpt_2_info);
4991
4992    // This range represent an selection with end-point just inside excerpt_2
4993    // Today we only expand the first excerpt, but another interpretation that
4994    // we could consider is expanding both here
4995    let excerpts: Vec<_> = snapshot.excerpts_for_range(p10..p20).collect();
4996    assert_eq!(excerpts.len(), 1);
4997    assert_eq!(excerpts[0].info(), excerpt_1_info);
4998
4999    //// Test that `excerpts_for_range` and `excerpt_containing` agree for all single offsets (cursor positions)
5000    for offset in 0..=snapshot.len().0 {
5001        let offset = MultiBufferOffset(offset);
5002        let excerpts_for_range: Vec<_> = snapshot.excerpts_for_range(offset..offset).collect();
5003        assert_eq!(
5004            excerpts_for_range.len(),
5005            1,
5006            "Expected exactly one excerpt for offset {offset}",
5007        );
5008
5009        let excerpt_containing = snapshot.excerpt_containing(offset..offset);
5010        assert!(
5011            excerpt_containing.is_some(),
5012            "Expected excerpt_containing to find excerpt for offset {offset}",
5013        );
5014
5015        assert_eq!(
5016            excerpts_for_range[0].info(),
5017            excerpt_containing.unwrap().excerpt.info(),
5018            "excerpts_for_range and excerpt_containing should agree for offset {offset}",
5019        );
5020    }
5021
5022    //// Test `excerpt_containing` behavior with ranges:
5023
5024    // Ranges intersecting a single-excerpt
5025    let containing = snapshot.excerpt_containing(p00..p13);
5026    assert!(containing.is_some());
5027    assert_eq!(containing.unwrap().excerpt.info(), excerpt_1_info);
5028
5029    // Ranges intersecting multiple excerpts (should return None)
5030    let containing = snapshot.excerpt_containing(p20..p40);
5031    assert!(
5032        containing.is_none(),
5033        "excerpt_containing should return None for ranges spanning multiple excerpts"
5034    );
5035}
5036
5037#[gpui::test]
5038fn test_range_to_buffer_ranges(cx: &mut App) {
5039    let buffer_1 = cx.new(|cx| Buffer::local("aaa\nbbb", cx));
5040    let buffer_2 = cx.new(|cx| Buffer::local("ccc", cx));
5041
5042    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5043    multibuffer.update(cx, |multibuffer, cx| {
5044        multibuffer.set_excerpts_for_path(
5045            PathKey::sorted(0),
5046            buffer_1.clone(),
5047            [Point::new(0, 0)..Point::new(1, 3)],
5048            0,
5049            cx,
5050        );
5051
5052        multibuffer.set_excerpts_for_path(
5053            PathKey::sorted(1),
5054            buffer_2.clone(),
5055            [Point::new(0, 0)..Point::new(0, 3)],
5056            0,
5057            cx,
5058        );
5059    });
5060
5061    let snapshot = multibuffer.read(cx).snapshot(cx);
5062    assert_eq!(snapshot.text(), "aaa\nbbb\nccc");
5063
5064    let excerpt_2_start = Point::new(2, 0);
5065
5066    let ranges_half_open = snapshot.range_to_buffer_ranges(Point::zero()..excerpt_2_start);
5067    assert_eq!(
5068        ranges_half_open.len(),
5069        1,
5070        "Half-open range ending at excerpt start should EXCLUDE that excerpt"
5071    );
5072    assert_eq!(ranges_half_open[0].1, BufferOffset(0)..BufferOffset(7));
5073    assert_eq!(
5074        ranges_half_open[0].0.remote_id(),
5075        buffer_1.read(cx).remote_id()
5076    );
5077
5078    let buffer_empty = cx.new(|cx| Buffer::local("", cx));
5079    let multibuffer_trailing_empty = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5080    let (te_excerpt_1_info, te_excerpt_2_info) =
5081        multibuffer_trailing_empty.update(cx, |multibuffer, cx| {
5082            multibuffer.set_excerpts_for_path(
5083                PathKey::sorted(0),
5084                buffer_1.clone(),
5085                [Point::new(0, 0)..Point::new(1, 3)],
5086                0,
5087                cx,
5088            );
5089
5090            multibuffer.set_excerpts_for_path(
5091                PathKey::sorted(1),
5092                buffer_empty.clone(),
5093                [Point::new(0, 0)..Point::new(0, 0)],
5094                0,
5095                cx,
5096            );
5097
5098            let snapshot = multibuffer.snapshot(cx);
5099            let mut infos = snapshot.excerpts().map(|(_, info)| info);
5100            (infos.next().unwrap(), infos.next().unwrap())
5101        });
5102
5103    let snapshot_trailing = multibuffer_trailing_empty.read(cx).snapshot(cx);
5104    assert_eq!(snapshot_trailing.text(), "aaa\nbbb\n");
5105
5106    let max_point = snapshot_trailing.max_point();
5107
5108    let ranges_half_open_max =
5109        snapshot_trailing.range_to_buffer_ranges_with_context(Point::zero()..max_point);
5110    assert_eq!(
5111        ranges_half_open_max.len(),
5112        2,
5113        "Should include trailing empty excerpts"
5114    );
5115    assert_eq!(ranges_half_open_max[0].2, te_excerpt_1_info.range);
5116}
5117
5118#[gpui::test]
5119fn test_cannot_seek_backward_after_excerpt_replacement(cx: &mut TestAppContext) {
5120    let buffer_b_text: String = (0..50).map(|i| format!("line_b {i}\n")).collect();
5121    let buffer_b = cx.new(|cx| Buffer::local(buffer_b_text, cx));
5122
5123    let buffer_c_text: String = (0..10).map(|i| format!("line_c {i}\n")).collect();
5124    let buffer_c = cx.new(|cx| Buffer::local(buffer_c_text, cx));
5125
5126    let buffer_d_text: String = (0..10).map(|i| format!("line_d {i}\n")).collect();
5127    let buffer_d = cx.new(|cx| Buffer::local(buffer_d_text, cx));
5128
5129    let path_b = PathKey::with_sort_prefix(0, rel_path("bbb.rs").into_arc());
5130    let path_c = PathKey::with_sort_prefix(0, rel_path("ddd.rs").into_arc());
5131    let path_d = PathKey::with_sort_prefix(0, rel_path("ccc.rs").into_arc());
5132
5133    let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));
5134
5135    multibuffer.update(cx, |multibuffer, cx| {
5136        multibuffer.set_excerpts_for_path(
5137            path_b.clone(),
5138            buffer_b.clone(),
5139            vec![
5140                Point::row_range(0..3),
5141                Point::row_range(15..18),
5142                Point::row_range(30..33),
5143            ],
5144            0,
5145            cx,
5146        );
5147    });
5148
5149    multibuffer.update(cx, |multibuffer, cx| {
5150        multibuffer.set_excerpts_for_path(
5151            path_c.clone(),
5152            buffer_c.clone(),
5153            vec![Point::row_range(0..3)],
5154            0,
5155            cx,
5156        );
5157    });
5158
5159    let (anchor_in_e_b2, anchor_in_e_b3) = multibuffer.read_with(cx, |multibuffer, cx| {
5160        let snapshot = multibuffer.snapshot(cx);
5161        let excerpt_infos: Vec<ExcerptInfo> = snapshot.excerpts().map(|(_, info)| info).collect();
5162        assert_eq!(excerpt_infos.len(), 4, "expected 4 excerpts (3×B + 1×C)");
5163
5164        let e_b2_info = excerpt_infos[1].clone();
5165        let e_b3_info = excerpt_infos[2].clone();
5166
5167        let anchor_b2 = Anchor::in_buffer(e_b2_info.path_key_index, e_b2_info.range.start);
5168        let anchor_b3 = Anchor::in_buffer(e_b3_info.path_key_index, e_b3_info.range.start);
5169        (anchor_b2, anchor_b3)
5170    });
5171
5172    multibuffer.update(cx, |multibuffer, cx| {
5173        multibuffer.set_excerpts_for_path(
5174            path_b.clone(),
5175            buffer_b.clone(),
5176            vec![Point::row_range(0..3), Point::row_range(28..36)],
5177            0,
5178            cx,
5179        );
5180    });
5181
5182    multibuffer.update(cx, |multibuffer, cx| {
5183        multibuffer.set_excerpts_for_path(
5184            path_d.clone(),
5185            buffer_d.clone(),
5186            vec![Point::row_range(0..3)],
5187            0,
5188            cx,
5189        );
5190    });
5191
5192    multibuffer.read_with(cx, |multibuffer, cx| {
5193        let snapshot = multibuffer.snapshot(cx);
5194        snapshot.summaries_for_anchors::<Point, _>(&[anchor_in_e_b2, anchor_in_e_b3]);
5195    });
5196}