multi_buffer_tests.rs

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