1use super::{
   2    fold_map,
   3    tab_map::{self, TabEdit, TabPoint, TabSnapshot},
   4};
   5use crate::{MultiBufferSnapshot, Point};
   6use gpui::{
   7    fonts::FontId, text_layout::LineWrapper, Entity, ModelContext, ModelHandle, MutableAppContext,
   8    Task,
   9};
  10use language::Chunk;
  11use lazy_static::lazy_static;
  12use smol::future::yield_now;
  13use std::{cmp, collections::VecDeque, mem, ops::Range, time::Duration};
  14use sum_tree::{Bias, Cursor, SumTree};
  15use text::Patch;
  16
  17pub use super::tab_map::TextSummary;
  18pub type WrapEdit = text::Edit<u32>;
  19
  20pub struct WrapMap {
  21    snapshot: WrapSnapshot,
  22    pending_edits: VecDeque<(TabSnapshot, Vec<TabEdit>)>,
  23    interpolated_edits: Patch<u32>,
  24    edits_since_sync: Patch<u32>,
  25    wrap_width: Option<f32>,
  26    background_task: Option<Task<()>>,
  27    font: (FontId, f32),
  28}
  29
  30impl Entity for WrapMap {
  31    type Event = ();
  32}
  33
  34#[derive(Clone)]
  35pub struct WrapSnapshot {
  36    tab_snapshot: TabSnapshot,
  37    transforms: SumTree<Transform>,
  38    interpolated: bool,
  39}
  40
  41#[derive(Clone, Debug, Default, Eq, PartialEq)]
  42struct Transform {
  43    summary: TransformSummary,
  44    display_text: Option<&'static str>,
  45}
  46
  47#[derive(Clone, Debug, Default, Eq, PartialEq)]
  48struct TransformSummary {
  49    input: TextSummary,
  50    output: TextSummary,
  51}
  52
  53#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  54pub struct WrapPoint(pub super::Point);
  55
  56pub struct WrapChunks<'a> {
  57    input_chunks: tab_map::TabChunks<'a>,
  58    input_chunk: Chunk<'a>,
  59    output_position: WrapPoint,
  60    max_output_row: u32,
  61    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  62}
  63
  64pub struct WrapBufferRows<'a> {
  65    input_buffer_rows: fold_map::FoldBufferRows<'a>,
  66    input_buffer_row: Option<u32>,
  67    output_row: u32,
  68    soft_wrapped: bool,
  69    max_output_row: u32,
  70    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  71}
  72
  73impl WrapMap {
  74    pub fn new(
  75        tab_snapshot: TabSnapshot,
  76        font_id: FontId,
  77        font_size: f32,
  78        wrap_width: Option<f32>,
  79        cx: &mut MutableAppContext,
  80    ) -> (ModelHandle<Self>, WrapSnapshot) {
  81        let handle = cx.add_model(|cx| {
  82            let mut this = Self {
  83                font: (font_id, font_size),
  84                wrap_width: None,
  85                pending_edits: Default::default(),
  86                interpolated_edits: Default::default(),
  87                edits_since_sync: Default::default(),
  88                snapshot: WrapSnapshot::new(tab_snapshot),
  89                background_task: None,
  90            };
  91            this.set_wrap_width(wrap_width, cx);
  92            mem::take(&mut this.edits_since_sync);
  93            this
  94        });
  95        let snapshot = handle.read(cx).snapshot.clone();
  96        (handle, snapshot)
  97    }
  98
  99    #[cfg(test)]
 100    pub fn is_rewrapping(&self) -> bool {
 101        self.background_task.is_some()
 102    }
 103
 104    pub fn sync(
 105        &mut self,
 106        tab_snapshot: TabSnapshot,
 107        edits: Vec<TabEdit>,
 108        cx: &mut ModelContext<Self>,
 109    ) -> (WrapSnapshot, Vec<WrapEdit>) {
 110        if self.wrap_width.is_some() {
 111            self.pending_edits.push_back((tab_snapshot, edits));
 112            self.flush_edits(cx);
 113        } else {
 114            self.edits_since_sync = self
 115                .edits_since_sync
 116                .compose(&self.snapshot.interpolate(tab_snapshot, &edits));
 117            self.snapshot.interpolated = false;
 118        }
 119
 120        (
 121            self.snapshot.clone(),
 122            mem::take(&mut self.edits_since_sync).into_inner(),
 123        )
 124    }
 125
 126    pub fn set_font(&mut self, font_id: FontId, font_size: f32, cx: &mut ModelContext<Self>) {
 127        if (font_id, font_size) != self.font {
 128            self.font = (font_id, font_size);
 129            self.rewrap(cx)
 130        }
 131    }
 132
 133    pub fn set_wrap_width(&mut self, wrap_width: Option<f32>, cx: &mut ModelContext<Self>) -> bool {
 134        if wrap_width == self.wrap_width {
 135            return false;
 136        }
 137
 138        self.wrap_width = wrap_width;
 139        self.rewrap(cx);
 140        true
 141    }
 142
 143    fn rewrap(&mut self, cx: &mut ModelContext<Self>) {
 144        self.background_task.take();
 145        self.interpolated_edits.clear();
 146        self.pending_edits.clear();
 147
 148        if let Some(wrap_width) = self.wrap_width {
 149            let mut new_snapshot = self.snapshot.clone();
 150            let font_cache = cx.font_cache().clone();
 151            let (font_id, font_size) = self.font;
 152            let task = cx.background().spawn(async move {
 153                let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 154                let tab_snapshot = new_snapshot.tab_snapshot.clone();
 155                let range = TabPoint::zero()..tab_snapshot.max_point();
 156                let edits = new_snapshot
 157                    .update(
 158                        tab_snapshot,
 159                        &[TabEdit {
 160                            old: range.clone(),
 161                            new: range.clone(),
 162                        }],
 163                        wrap_width,
 164                        &mut line_wrapper,
 165                    )
 166                    .await;
 167                (new_snapshot, edits)
 168            });
 169
 170            match cx
 171                .background()
 172                .block_with_timeout(Duration::from_millis(5), task)
 173            {
 174                Ok((snapshot, edits)) => {
 175                    self.snapshot = snapshot;
 176                    self.edits_since_sync = self.edits_since_sync.compose(&edits);
 177                    cx.notify();
 178                }
 179                Err(wrap_task) => {
 180                    self.background_task = Some(cx.spawn(|this, mut cx| async move {
 181                        let (snapshot, edits) = wrap_task.await;
 182                        this.update(&mut cx, |this, cx| {
 183                            this.snapshot = snapshot;
 184                            this.edits_since_sync = this
 185                                .edits_since_sync
 186                                .compose(mem::take(&mut this.interpolated_edits).invert())
 187                                .compose(&edits);
 188                            this.background_task = None;
 189                            this.flush_edits(cx);
 190                            cx.notify();
 191                        });
 192                    }));
 193                }
 194            }
 195        } else {
 196            let old_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 197            self.snapshot.transforms = SumTree::new();
 198            let summary = self.snapshot.tab_snapshot.text_summary();
 199            if !summary.lines.is_zero() {
 200                self.snapshot
 201                    .transforms
 202                    .push(Transform::isomorphic(summary), &());
 203            }
 204            let new_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 205            self.snapshot.interpolated = false;
 206            self.edits_since_sync = self.edits_since_sync.compose(&Patch::new(vec![WrapEdit {
 207                old: 0..old_rows,
 208                new: 0..new_rows,
 209            }]));
 210        }
 211    }
 212
 213    fn flush_edits(&mut self, cx: &mut ModelContext<Self>) {
 214        if !self.snapshot.interpolated {
 215            let mut to_remove_len = 0;
 216            for (tab_snapshot, _) in &self.pending_edits {
 217                if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 218                    to_remove_len += 1;
 219                } else {
 220                    break;
 221                }
 222            }
 223            self.pending_edits.drain(..to_remove_len);
 224        }
 225
 226        if self.pending_edits.is_empty() {
 227            return;
 228        }
 229
 230        if let Some(wrap_width) = self.wrap_width {
 231            if self.background_task.is_none() {
 232                let pending_edits = self.pending_edits.clone();
 233                let mut snapshot = self.snapshot.clone();
 234                let font_cache = cx.font_cache().clone();
 235                let (font_id, font_size) = self.font;
 236                let update_task = cx.background().spawn(async move {
 237                    let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 238
 239                    let mut edits = Patch::default();
 240                    for (tab_snapshot, tab_edits) in pending_edits {
 241                        let wrap_edits = snapshot
 242                            .update(tab_snapshot, &tab_edits, wrap_width, &mut line_wrapper)
 243                            .await;
 244                        edits = edits.compose(&wrap_edits);
 245                    }
 246                    (snapshot, edits)
 247                });
 248
 249                match cx
 250                    .background()
 251                    .block_with_timeout(Duration::from_millis(1), update_task)
 252                {
 253                    Ok((snapshot, output_edits)) => {
 254                        self.snapshot = snapshot;
 255                        self.edits_since_sync = self.edits_since_sync.compose(&output_edits);
 256                    }
 257                    Err(update_task) => {
 258                        self.background_task = Some(cx.spawn(|this, mut cx| async move {
 259                            let (snapshot, edits) = update_task.await;
 260                            this.update(&mut cx, |this, cx| {
 261                                this.snapshot = snapshot;
 262                                this.edits_since_sync = this
 263                                    .edits_since_sync
 264                                    .compose(mem::take(&mut this.interpolated_edits).invert())
 265                                    .compose(&edits);
 266                                this.background_task = None;
 267                                this.flush_edits(cx);
 268                                cx.notify();
 269                            });
 270                        }));
 271                    }
 272                }
 273            }
 274        }
 275
 276        let was_interpolated = self.snapshot.interpolated;
 277        let mut to_remove_len = 0;
 278        for (tab_snapshot, edits) in &self.pending_edits {
 279            if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 280                to_remove_len += 1;
 281            } else {
 282                let interpolated_edits = self.snapshot.interpolate(tab_snapshot.clone(), &edits);
 283                self.edits_since_sync = self.edits_since_sync.compose(&interpolated_edits);
 284                self.interpolated_edits = self.interpolated_edits.compose(&interpolated_edits);
 285            }
 286        }
 287
 288        if !was_interpolated {
 289            self.pending_edits.drain(..to_remove_len);
 290        }
 291    }
 292}
 293
 294impl WrapSnapshot {
 295    fn new(tab_snapshot: TabSnapshot) -> Self {
 296        let mut transforms = SumTree::new();
 297        let extent = tab_snapshot.text_summary();
 298        if !extent.lines.is_zero() {
 299            transforms.push(Transform::isomorphic(extent), &());
 300        }
 301        Self {
 302            transforms,
 303            tab_snapshot,
 304            interpolated: true,
 305        }
 306    }
 307
 308    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
 309        self.tab_snapshot.buffer_snapshot()
 310    }
 311
 312    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
 313        let mut new_transforms;
 314        if tab_edits.is_empty() {
 315            new_transforms = self.transforms.clone();
 316        } else {
 317            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 318
 319            let mut tab_edits_iter = tab_edits.iter().peekable();
 320            new_transforms =
 321                old_cursor.slice(&tab_edits_iter.peek().unwrap().old.start, Bias::Right, &());
 322
 323            while let Some(edit) = tab_edits_iter.next() {
 324                if edit.new.start > TabPoint::from(new_transforms.summary().input.lines) {
 325                    let summary = new_tab_snapshot.text_summary_for_range(
 326                        TabPoint::from(new_transforms.summary().input.lines)..edit.new.start,
 327                    );
 328                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 329                }
 330
 331                if !edit.new.is_empty() {
 332                    new_transforms.push_or_extend(Transform::isomorphic(
 333                        new_tab_snapshot.text_summary_for_range(edit.new.clone()),
 334                    ));
 335                }
 336
 337                old_cursor.seek_forward(&edit.old.end, Bias::Right, &());
 338                if let Some(next_edit) = tab_edits_iter.peek() {
 339                    if next_edit.old.start > old_cursor.end(&()) {
 340                        if old_cursor.end(&()) > edit.old.end {
 341                            let summary = self
 342                                .tab_snapshot
 343                                .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 344                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 345                        }
 346
 347                        old_cursor.next(&());
 348                        new_transforms.push_tree(
 349                            old_cursor.slice(&next_edit.old.start, Bias::Right, &()),
 350                            &(),
 351                        );
 352                    }
 353                } else {
 354                    if old_cursor.end(&()) > edit.old.end {
 355                        let summary = self
 356                            .tab_snapshot
 357                            .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 358                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 359                    }
 360                    old_cursor.next(&());
 361                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 362                }
 363            }
 364        }
 365
 366        let old_snapshot = mem::replace(
 367            self,
 368            WrapSnapshot {
 369                tab_snapshot: new_tab_snapshot,
 370                transforms: new_transforms,
 371                interpolated: true,
 372            },
 373        );
 374        self.check_invariants();
 375        old_snapshot.compute_edits(tab_edits, self)
 376    }
 377
 378    async fn update(
 379        &mut self,
 380        new_tab_snapshot: TabSnapshot,
 381        tab_edits: &[TabEdit],
 382        wrap_width: f32,
 383        line_wrapper: &mut LineWrapper,
 384    ) -> Patch<u32> {
 385        #[derive(Debug)]
 386        struct RowEdit {
 387            old_rows: Range<u32>,
 388            new_rows: Range<u32>,
 389        }
 390
 391        let mut tab_edits_iter = tab_edits.into_iter().peekable();
 392        let mut row_edits = Vec::new();
 393        while let Some(edit) = tab_edits_iter.next() {
 394            let mut row_edit = RowEdit {
 395                old_rows: edit.old.start.row()..edit.old.end.row() + 1,
 396                new_rows: edit.new.start.row()..edit.new.end.row() + 1,
 397            };
 398
 399            while let Some(next_edit) = tab_edits_iter.peek() {
 400                if next_edit.old.start.row() <= row_edit.old_rows.end {
 401                    row_edit.old_rows.end = next_edit.old.end.row() + 1;
 402                    row_edit.new_rows.end = next_edit.new.end.row() + 1;
 403                    tab_edits_iter.next();
 404                } else {
 405                    break;
 406                }
 407            }
 408
 409            row_edits.push(row_edit);
 410        }
 411
 412        let mut new_transforms;
 413        if row_edits.is_empty() {
 414            new_transforms = self.transforms.clone();
 415        } else {
 416            let mut row_edits = row_edits.into_iter().peekable();
 417            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 418
 419            new_transforms = old_cursor.slice(
 420                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 421                Bias::Right,
 422                &(),
 423            );
 424
 425            while let Some(edit) = row_edits.next() {
 426                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 427                    let summary = new_tab_snapshot.text_summary_for_range(
 428                        TabPoint(new_transforms.summary().input.lines)
 429                            ..TabPoint::new(edit.new_rows.start, 0),
 430                    );
 431                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 432                }
 433
 434                let mut line = String::new();
 435                let mut remaining = None;
 436                let mut chunks = new_tab_snapshot
 437                    .chunks(TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point());
 438                let mut edit_transforms = Vec::<Transform>::new();
 439                for _ in edit.new_rows.start..edit.new_rows.end {
 440                    while let Some(chunk) =
 441                        remaining.take().or_else(|| chunks.next().map(|c| c.text))
 442                    {
 443                        if let Some(ix) = chunk.find('\n') {
 444                            line.push_str(&chunk[..ix + 1]);
 445                            remaining = Some(&chunk[ix + 1..]);
 446                            break;
 447                        } else {
 448                            line.push_str(chunk)
 449                        }
 450                    }
 451
 452                    if line.is_empty() {
 453                        break;
 454                    }
 455
 456                    let mut prev_boundary_ix = 0;
 457                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 458                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 459                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 460                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 461                        prev_boundary_ix = boundary.ix;
 462                    }
 463
 464                    if prev_boundary_ix < line.len() {
 465                        push_isomorphic(
 466                            &mut edit_transforms,
 467                            TextSummary::from(&line[prev_boundary_ix..]),
 468                        );
 469                    }
 470
 471                    line.clear();
 472                    yield_now().await;
 473                }
 474
 475                let mut edit_transforms = edit_transforms.into_iter();
 476                if let Some(transform) = edit_transforms.next() {
 477                    new_transforms.push_or_extend(transform);
 478                }
 479                new_transforms.extend(edit_transforms, &());
 480
 481                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 482                if let Some(next_edit) = row_edits.peek() {
 483                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 484                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 485                            let summary = self.tab_snapshot.text_summary_for_range(
 486                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 487                            );
 488                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 489                        }
 490                        old_cursor.next(&());
 491                        new_transforms.push_tree(
 492                            old_cursor.slice(
 493                                &TabPoint::new(next_edit.old_rows.start, 0),
 494                                Bias::Right,
 495                                &(),
 496                            ),
 497                            &(),
 498                        );
 499                    }
 500                } else {
 501                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 502                        let summary = self.tab_snapshot.text_summary_for_range(
 503                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 504                        );
 505                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 506                    }
 507                    old_cursor.next(&());
 508                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 509                }
 510            }
 511        }
 512
 513        let old_snapshot = mem::replace(
 514            self,
 515            WrapSnapshot {
 516                tab_snapshot: new_tab_snapshot,
 517                transforms: new_transforms,
 518                interpolated: false,
 519            },
 520        );
 521        self.check_invariants();
 522        old_snapshot.compute_edits(tab_edits, self)
 523    }
 524
 525    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &WrapSnapshot) -> Patch<u32> {
 526        let mut wrap_edits = Vec::new();
 527        let mut old_cursor = self.transforms.cursor::<TransformSummary>();
 528        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
 529        for mut tab_edit in tab_edits.iter().cloned() {
 530            tab_edit.old.start.0.column = 0;
 531            tab_edit.old.end.0 += Point::new(1, 0);
 532            tab_edit.new.start.0.column = 0;
 533            tab_edit.new.end.0 += Point::new(1, 0);
 534
 535            old_cursor.seek(&tab_edit.old.start, Bias::Right, &());
 536            let mut old_start = old_cursor.start().output.lines;
 537            old_start += tab_edit.old.start.0 - old_cursor.start().input.lines;
 538
 539            old_cursor.seek(&tab_edit.old.end, Bias::Right, &());
 540            let mut old_end = old_cursor.start().output.lines;
 541            old_end += tab_edit.old.end.0 - old_cursor.start().input.lines;
 542
 543            new_cursor.seek(&tab_edit.new.start, Bias::Right, &());
 544            let mut new_start = new_cursor.start().output.lines;
 545            new_start += tab_edit.new.start.0 - new_cursor.start().input.lines;
 546
 547            new_cursor.seek(&tab_edit.new.end, Bias::Right, &());
 548            let mut new_end = new_cursor.start().output.lines;
 549            new_end += tab_edit.new.end.0 - new_cursor.start().input.lines;
 550
 551            wrap_edits.push(WrapEdit {
 552                old: old_start.row..old_end.row,
 553                new: new_start.row..new_end.row,
 554            });
 555        }
 556
 557        consolidate_wrap_edits(&mut wrap_edits);
 558        Patch::new(wrap_edits)
 559    }
 560
 561    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
 562        self.chunks(wrap_row..self.max_point().row() + 1)
 563            .map(|h| h.text)
 564    }
 565
 566    pub fn chunks<'a>(&'a self, rows: Range<u32>) -> WrapChunks<'a> {
 567        let output_start = WrapPoint::new(rows.start, 0);
 568        let output_end = WrapPoint::new(rows.end, 0);
 569        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 570        transforms.seek(&output_start, Bias::Right, &());
 571        let mut input_start = TabPoint(transforms.start().1 .0);
 572        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 573            input_start.0 += output_start.0 - transforms.start().0 .0;
 574        }
 575        let input_end = self
 576            .to_tab_point(output_end)
 577            .min(self.tab_snapshot.max_point());
 578        WrapChunks {
 579            input_chunks: self.tab_snapshot.chunks(input_start..input_end),
 580            input_chunk: Default::default(),
 581            output_position: output_start,
 582            max_output_row: rows.end,
 583            transforms,
 584        }
 585    }
 586
 587    pub fn text_summary(&self) -> TextSummary {
 588        self.transforms.summary().output
 589    }
 590
 591    pub fn max_point(&self) -> WrapPoint {
 592        WrapPoint(self.transforms.summary().output.lines)
 593    }
 594
 595    pub fn line_len(&self, row: u32) -> u32 {
 596        let mut len = 0;
 597        for chunk in self.text_chunks(row) {
 598            if let Some(newline_ix) = chunk.find('\n') {
 599                len += newline_ix;
 600                break;
 601            } else {
 602                len += chunk.len();
 603            }
 604        }
 605        len as u32
 606    }
 607
 608    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 609        let mut cursor = self.transforms.cursor::<WrapPoint>();
 610        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 611        cursor.item().and_then(|transform| {
 612            if transform.is_isomorphic() {
 613                None
 614            } else {
 615                Some(transform.summary.output.lines.column)
 616            }
 617        })
 618    }
 619
 620    pub fn longest_row(&self) -> u32 {
 621        self.transforms.summary().output.longest_row
 622    }
 623
 624    pub fn buffer_rows(&self, start_row: u32) -> WrapBufferRows {
 625        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 626        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 627        let mut input_row = transforms.start().1.row();
 628        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 629            input_row += start_row - transforms.start().0.row();
 630        }
 631        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 632        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 633        let input_buffer_row = input_buffer_rows.next().unwrap();
 634        WrapBufferRows {
 635            transforms,
 636            input_buffer_row,
 637            input_buffer_rows,
 638            output_row: start_row,
 639            soft_wrapped,
 640            max_output_row: self.max_point().row(),
 641        }
 642    }
 643
 644    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 645        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 646        cursor.seek(&point, Bias::Right, &());
 647        let mut tab_point = cursor.start().1 .0;
 648        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 649            tab_point += point.0 - cursor.start().0 .0;
 650        }
 651        TabPoint(tab_point)
 652    }
 653
 654    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 655        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 656    }
 657
 658    pub fn from_point(&self, point: Point, bias: Bias) -> WrapPoint {
 659        self.from_tab_point(self.tab_snapshot.from_point(point, bias))
 660    }
 661
 662    pub fn from_tab_point(&self, point: TabPoint) -> WrapPoint {
 663        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 664        cursor.seek(&point, Bias::Right, &());
 665        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 666    }
 667
 668    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 669        if bias == Bias::Left {
 670            let mut cursor = self.transforms.cursor::<WrapPoint>();
 671            cursor.seek(&point, Bias::Right, &());
 672            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 673                point = *cursor.start();
 674                *point.column_mut() -= 1;
 675            }
 676        }
 677
 678        self.from_tab_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 679    }
 680
 681    pub fn prev_row_boundary(&self, mut point: WrapPoint) -> u32 {
 682        if self.transforms.is_empty() {
 683            return 0;
 684        }
 685
 686        *point.column_mut() = 0;
 687
 688        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 689        cursor.seek(&point, Bias::Right, &());
 690        if cursor.item().is_none() {
 691            cursor.prev(&());
 692        }
 693
 694        while let Some(transform) = cursor.item() {
 695            if transform.is_isomorphic() && cursor.start().1.column() == 0 {
 696                return cmp::min(cursor.end(&()).0.row(), point.row());
 697            } else {
 698                cursor.prev(&());
 699            }
 700        }
 701
 702        unreachable!()
 703    }
 704
 705    pub fn next_row_boundary(&self, mut point: WrapPoint) -> Option<u32> {
 706        point.0 += Point::new(1, 0);
 707
 708        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 709        cursor.seek(&point, Bias::Right, &());
 710        while let Some(transform) = cursor.item() {
 711            if transform.is_isomorphic() && cursor.start().1.column() == 0 {
 712                return Some(cmp::max(cursor.start().0.row(), point.row()));
 713            } else {
 714                cursor.next(&());
 715            }
 716        }
 717
 718        None
 719    }
 720
 721    fn check_invariants(&self) {
 722        #[cfg(test)]
 723        {
 724            assert_eq!(
 725                TabPoint::from(self.transforms.summary().input.lines),
 726                self.tab_snapshot.max_point()
 727            );
 728
 729            {
 730                let mut transforms = self.transforms.cursor::<()>().peekable();
 731                while let Some(transform) = transforms.next() {
 732                    if let Some(next_transform) = transforms.peek() {
 733                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 734                    }
 735                }
 736            }
 737
 738            let input_buffer_rows = self.buffer_snapshot().buffer_rows(0).collect::<Vec<_>>();
 739            let mut expected_buffer_rows = Vec::new();
 740            let mut prev_tab_row = 0;
 741            for display_row in 0..=self.max_point().row() {
 742                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 743                if tab_point.row() == prev_tab_row && display_row != 0 {
 744                    expected_buffer_rows.push(None);
 745                } else {
 746                    let fold_point = self.tab_snapshot.to_fold_point(tab_point, Bias::Left).0;
 747                    let buffer_point = fold_point.to_buffer_point(&self.tab_snapshot.fold_snapshot);
 748                    expected_buffer_rows.push(input_buffer_rows[buffer_point.row as usize]);
 749                    prev_tab_row = tab_point.row();
 750                }
 751            }
 752
 753            for start_display_row in 0..expected_buffer_rows.len() {
 754                assert_eq!(
 755                    self.buffer_rows(start_display_row as u32)
 756                        .collect::<Vec<_>>(),
 757                    &expected_buffer_rows[start_display_row..],
 758                    "invalid buffer_rows({}..)",
 759                    start_display_row
 760                );
 761            }
 762        }
 763    }
 764}
 765
 766impl<'a> Iterator for WrapChunks<'a> {
 767    type Item = Chunk<'a>;
 768
 769    fn next(&mut self) -> Option<Self::Item> {
 770        if self.output_position.row() >= self.max_output_row {
 771            return None;
 772        }
 773
 774        let transform = self.transforms.item()?;
 775        if let Some(display_text) = transform.display_text {
 776            let mut start_ix = 0;
 777            let mut end_ix = display_text.len();
 778            let mut summary = transform.summary.output.lines;
 779
 780            if self.output_position > self.transforms.start().0 {
 781                // Exclude newline starting prior to the desired row.
 782                start_ix = 1;
 783                summary.row = 0;
 784            } else if self.output_position.row() + 1 >= self.max_output_row {
 785                // Exclude soft indentation ending after the desired row.
 786                end_ix = 1;
 787                summary.column = 0;
 788            }
 789
 790            self.output_position.0 += summary;
 791            self.transforms.next(&());
 792            return Some(Chunk {
 793                text: &display_text[start_ix..end_ix],
 794                ..self.input_chunk
 795            });
 796        }
 797
 798        if self.input_chunk.text.is_empty() {
 799            self.input_chunk = self.input_chunks.next().unwrap();
 800        }
 801
 802        let mut input_len = 0;
 803        let transform_end = self.transforms.end(&()).0;
 804        for c in self.input_chunk.text.chars() {
 805            let char_len = c.len_utf8();
 806            input_len += char_len;
 807            if c == '\n' {
 808                *self.output_position.row_mut() += 1;
 809                *self.output_position.column_mut() = 0;
 810            } else {
 811                *self.output_position.column_mut() += char_len as u32;
 812            }
 813
 814            if self.output_position >= transform_end {
 815                self.transforms.next(&());
 816                break;
 817            }
 818        }
 819
 820        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 821        self.input_chunk.text = suffix;
 822        Some(Chunk {
 823            text: prefix,
 824            ..self.input_chunk
 825        })
 826    }
 827}
 828
 829impl<'a> Iterator for WrapBufferRows<'a> {
 830    type Item = Option<u32>;
 831
 832    fn next(&mut self) -> Option<Self::Item> {
 833        if self.output_row > self.max_output_row {
 834            return None;
 835        }
 836
 837        let buffer_row = self.input_buffer_row;
 838        let soft_wrapped = self.soft_wrapped;
 839
 840        self.output_row += 1;
 841        self.transforms
 842            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 843        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 844            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 845            self.soft_wrapped = false;
 846        } else {
 847            self.soft_wrapped = true;
 848        }
 849
 850        Some(if soft_wrapped { None } else { buffer_row })
 851    }
 852}
 853
 854impl Transform {
 855    fn isomorphic(summary: TextSummary) -> Self {
 856        #[cfg(test)]
 857        assert!(!summary.lines.is_zero());
 858
 859        Self {
 860            summary: TransformSummary {
 861                input: summary.clone(),
 862                output: summary,
 863            },
 864            display_text: None,
 865        }
 866    }
 867
 868    fn wrap(indent: u32) -> Self {
 869        lazy_static! {
 870            static ref WRAP_TEXT: String = {
 871                let mut wrap_text = String::new();
 872                wrap_text.push('\n');
 873                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 874                wrap_text
 875            };
 876        }
 877
 878        Self {
 879            summary: TransformSummary {
 880                input: TextSummary::default(),
 881                output: TextSummary {
 882                    lines: Point::new(1, indent),
 883                    first_line_chars: 0,
 884                    last_line_chars: indent,
 885                    longest_row: 1,
 886                    longest_row_chars: indent,
 887                },
 888            },
 889            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 890        }
 891    }
 892
 893    fn is_isomorphic(&self) -> bool {
 894        self.display_text.is_none()
 895    }
 896}
 897
 898impl sum_tree::Item for Transform {
 899    type Summary = TransformSummary;
 900
 901    fn summary(&self) -> Self::Summary {
 902        self.summary.clone()
 903    }
 904}
 905
 906fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 907    if let Some(last_transform) = transforms.last_mut() {
 908        if last_transform.is_isomorphic() {
 909            last_transform.summary.input += &summary;
 910            last_transform.summary.output += &summary;
 911            return;
 912        }
 913    }
 914    transforms.push(Transform::isomorphic(summary));
 915}
 916
 917trait SumTreeExt {
 918    fn push_or_extend(&mut self, transform: Transform);
 919}
 920
 921impl SumTreeExt for SumTree<Transform> {
 922    fn push_or_extend(&mut self, transform: Transform) {
 923        let mut transform = Some(transform);
 924        self.update_last(
 925            |last_transform| {
 926                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
 927                    let transform = transform.take().unwrap();
 928                    last_transform.summary.input += &transform.summary.input;
 929                    last_transform.summary.output += &transform.summary.output;
 930                }
 931            },
 932            &(),
 933        );
 934
 935        if let Some(transform) = transform {
 936            self.push(transform, &());
 937        }
 938    }
 939}
 940
 941impl WrapPoint {
 942    pub fn new(row: u32, column: u32) -> Self {
 943        Self(super::Point::new(row, column))
 944    }
 945
 946    pub fn row(self) -> u32 {
 947        self.0.row
 948    }
 949
 950    pub fn row_mut(&mut self) -> &mut u32 {
 951        &mut self.0.row
 952    }
 953
 954    pub fn column(&self) -> u32 {
 955        self.0.column
 956    }
 957
 958    pub fn column_mut(&mut self) -> &mut u32 {
 959        &mut self.0.column
 960    }
 961}
 962
 963impl sum_tree::Summary for TransformSummary {
 964    type Context = ();
 965
 966    fn add_summary(&mut self, other: &Self, _: &()) {
 967        self.input += &other.input;
 968        self.output += &other.output;
 969    }
 970}
 971
 972impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
 973    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 974        self.0 += summary.input.lines;
 975    }
 976}
 977
 978impl<'a> sum_tree::SeekTarget<'a, TransformSummary, TransformSummary> for TabPoint {
 979    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
 980        Ord::cmp(&self.0, &cursor_location.input.lines)
 981    }
 982}
 983
 984impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
 985    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 986        self.0 += summary.output.lines;
 987    }
 988}
 989
 990fn consolidate_wrap_edits(edits: &mut Vec<WrapEdit>) {
 991    let mut i = 1;
 992    while i < edits.len() {
 993        let edit = edits[i].clone();
 994        let prev_edit = &mut edits[i - 1];
 995        if prev_edit.old.end >= edit.old.start {
 996            prev_edit.old.end = edit.old.end;
 997            prev_edit.new.end = edit.new.end;
 998            edits.remove(i);
 999            continue;
1000        }
1001        i += 1;
1002    }
1003}
1004
1005#[cfg(test)]
1006mod tests {
1007    use super::*;
1008    use crate::{
1009        display_map::{fold_map::FoldMap, tab_map::TabMap},
1010        MultiBuffer,
1011    };
1012    use gpui::test::observe;
1013    use language::RandomCharIter;
1014    use rand::prelude::*;
1015    use smol::stream::StreamExt;
1016    use std::{cmp, env};
1017    use text::Rope;
1018
1019    #[gpui::test(iterations = 100)]
1020    async fn test_random_wraps(mut cx: gpui::TestAppContext, mut rng: StdRng) {
1021        cx.foreground().set_block_on_ticks(0..=50);
1022        cx.foreground().forbid_parking();
1023        let operations = env::var("OPERATIONS")
1024            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1025            .unwrap_or(10);
1026
1027        let font_cache = cx.font_cache().clone();
1028        let font_system = cx.platform().fonts();
1029        let mut wrap_width = if rng.gen_bool(0.1) {
1030            None
1031        } else {
1032            Some(rng.gen_range(0.0..=1000.0))
1033        };
1034        let tab_size = rng.gen_range(1..=4);
1035        let family_id = font_cache.load_family(&["Helvetica"]).unwrap();
1036        let font_id = font_cache
1037            .select_font(family_id, &Default::default())
1038            .unwrap();
1039        let font_size = 14.0;
1040
1041        log::info!("Tab size: {}", tab_size);
1042        log::info!("Wrap width: {:?}", wrap_width);
1043
1044        let buffer = cx.update(|cx| {
1045            if rng.gen() {
1046                MultiBuffer::build_random(&mut rng, cx)
1047            } else {
1048                let len = rng.gen_range(0..10);
1049                let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1050                MultiBuffer::build_simple(&text, cx)
1051            }
1052        });
1053        let mut buffer_snapshot = buffer.read_with(&cx, |buffer, cx| buffer.snapshot(cx));
1054        let (mut fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1055        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1056        log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1057        log::info!(
1058            "Unwrapped text (unexpanded tabs): {:?}",
1059            folds_snapshot.text()
1060        );
1061        log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1062
1063        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1064        let unwrapped_text = tabs_snapshot.text();
1065        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1066
1067        let (wrap_map, _) =
1068            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
1069        let mut notifications = observe(&wrap_map, &mut cx);
1070
1071        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1072            notifications.next().await.unwrap();
1073        }
1074
1075        let (initial_snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
1076            assert!(!map.is_rewrapping());
1077            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1078        });
1079
1080        let actual_text = initial_snapshot.text();
1081        assert_eq!(
1082            actual_text, expected_text,
1083            "unwrapped text is: {:?}",
1084            unwrapped_text
1085        );
1086        log::info!("Wrapped text: {:?}", actual_text);
1087
1088        let mut edits = Vec::new();
1089        for _i in 0..operations {
1090            log::info!("{} ==============================================", _i);
1091
1092            let mut buffer_edits = Vec::new();
1093            match rng.gen_range(0..=100) {
1094                0..=19 => {
1095                    wrap_width = if rng.gen_bool(0.2) {
1096                        None
1097                    } else {
1098                        Some(rng.gen_range(0.0..=1000.0))
1099                    };
1100                    log::info!("Setting wrap width to {:?}", wrap_width);
1101                    wrap_map.update(&mut cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1102                }
1103                20..=39 => {
1104                    for (folds_snapshot, fold_edits) in fold_map.randomly_mutate(&mut rng) {
1105                        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1106                        let (mut snapshot, wrap_edits) = wrap_map
1107                            .update(&mut cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1108                        snapshot.check_invariants();
1109                        snapshot.verify_chunks(&mut rng);
1110                        edits.push((snapshot, wrap_edits));
1111                    }
1112                }
1113                _ => {
1114                    buffer.update(&mut cx, |buffer, cx| {
1115                        let subscription = buffer.subscribe();
1116                        let edit_count = rng.gen_range(1..=5);
1117                        buffer.randomly_edit(&mut rng, edit_count, cx);
1118                        buffer_snapshot = buffer.snapshot(cx);
1119                        buffer_edits.extend(subscription.consume());
1120                    });
1121                }
1122            }
1123
1124            log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1125            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1126            log::info!(
1127                "Unwrapped text (unexpanded tabs): {:?}",
1128                folds_snapshot.text()
1129            );
1130            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1131            log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1132
1133            let unwrapped_text = tabs_snapshot.text();
1134            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1135            let (mut snapshot, wrap_edits) = wrap_map.update(&mut cx, |map, cx| {
1136                map.sync(tabs_snapshot.clone(), tab_edits, cx)
1137            });
1138            snapshot.check_invariants();
1139            snapshot.verify_chunks(&mut rng);
1140            edits.push((snapshot, wrap_edits));
1141
1142            if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1143                log::info!("Waiting for wrapping to finish");
1144                while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1145                    notifications.next().await.unwrap();
1146                }
1147                wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1148            }
1149
1150            if !wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1151                let (mut wrapped_snapshot, wrap_edits) =
1152                    wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1153                let actual_text = wrapped_snapshot.text();
1154                let actual_longest_row = wrapped_snapshot.longest_row();
1155                log::info!("Wrapping finished: {:?}", actual_text);
1156                wrapped_snapshot.check_invariants();
1157                wrapped_snapshot.verify_chunks(&mut rng);
1158                edits.push((wrapped_snapshot.clone(), wrap_edits));
1159                assert_eq!(
1160                    actual_text, expected_text,
1161                    "unwrapped text is: {:?}",
1162                    unwrapped_text
1163                );
1164
1165                let mut summary = TextSummary::default();
1166                for (ix, item) in wrapped_snapshot
1167                    .transforms
1168                    .items(&())
1169                    .into_iter()
1170                    .enumerate()
1171                {
1172                    summary += &item.summary.output;
1173                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1174                }
1175
1176                if tab_size == 1
1177                    || !wrapped_snapshot
1178                        .tab_snapshot
1179                        .fold_snapshot
1180                        .text()
1181                        .contains('\t')
1182                {
1183                    let mut expected_longest_rows = Vec::new();
1184                    let mut longest_line_len = -1;
1185                    for (row, line) in expected_text.split('\n').enumerate() {
1186                        let line_char_count = line.chars().count() as isize;
1187                        if line_char_count > longest_line_len {
1188                            expected_longest_rows.clear();
1189                            longest_line_len = line_char_count;
1190                        }
1191                        if line_char_count >= longest_line_len {
1192                            expected_longest_rows.push(row as u32);
1193                        }
1194                    }
1195
1196                    assert!(
1197                        expected_longest_rows.contains(&actual_longest_row),
1198                        "incorrect longest row {}. expected {:?} with length {}",
1199                        actual_longest_row,
1200                        expected_longest_rows,
1201                        longest_line_len,
1202                    )
1203                }
1204            }
1205        }
1206
1207        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1208        for (snapshot, patch) in edits {
1209            let snapshot_text = Rope::from(snapshot.text().as_str());
1210            for edit in &patch {
1211                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1212                let old_end = initial_text.point_to_offset(cmp::min(
1213                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1214                    initial_text.max_point(),
1215                ));
1216                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1217                let new_end = snapshot_text.point_to_offset(cmp::min(
1218                    Point::new(edit.new.end, 0),
1219                    snapshot_text.max_point(),
1220                ));
1221                let new_text = snapshot_text
1222                    .chunks_in_range(new_start..new_end)
1223                    .collect::<String>();
1224
1225                initial_text.replace(old_start..old_end, &new_text);
1226            }
1227            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1228        }
1229
1230        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1231            log::info!("Waiting for wrapping to finish");
1232            while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1233                notifications.next().await.unwrap();
1234            }
1235        }
1236        wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1237    }
1238
1239    fn wrap_text(
1240        unwrapped_text: &str,
1241        wrap_width: Option<f32>,
1242        line_wrapper: &mut LineWrapper,
1243    ) -> String {
1244        if let Some(wrap_width) = wrap_width {
1245            let mut wrapped_text = String::new();
1246            for (row, line) in unwrapped_text.split('\n').enumerate() {
1247                if row > 0 {
1248                    wrapped_text.push('\n')
1249                }
1250
1251                let mut prev_ix = 0;
1252                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1253                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1254                    wrapped_text.push('\n');
1255                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1256                    prev_ix = boundary.ix;
1257                }
1258                wrapped_text.push_str(&line[prev_ix..]);
1259            }
1260            wrapped_text
1261        } else {
1262            unwrapped_text.to_string()
1263        }
1264    }
1265
1266    impl WrapSnapshot {
1267        pub fn text(&self) -> String {
1268            self.text_chunks(0).collect()
1269        }
1270
1271        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1272            for _ in 0..5 {
1273                let mut end_row = rng.gen_range(0..=self.max_point().row());
1274                let start_row = rng.gen_range(0..=end_row);
1275                end_row += 1;
1276
1277                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1278                if expected_text.ends_with("\n") {
1279                    expected_text.push('\n');
1280                }
1281                let mut expected_text = expected_text
1282                    .lines()
1283                    .take((end_row - start_row) as usize)
1284                    .collect::<Vec<_>>()
1285                    .join("\n");
1286                if end_row <= self.max_point().row() {
1287                    expected_text.push('\n');
1288                }
1289
1290                let actual_text = self
1291                    .chunks(start_row..end_row)
1292                    .map(|c| c.text)
1293                    .collect::<String>();
1294                assert_eq!(
1295                    expected_text,
1296                    actual_text,
1297                    "chunks != highlighted_chunks for rows {:?}",
1298                    start_row..end_row
1299                );
1300            }
1301        }
1302    }
1303}