1use super::{
   2    suggestion_map::SuggestionBufferRows,
   3    tab_map::{self, TabEdit, TabPoint, TabSnapshot},
   4    TextHighlights,
   5};
   6use crate::MultiBufferSnapshot;
   7use gpui::{
   8    fonts::{FontId, HighlightStyle},
   9    text_layout::LineWrapper,
  10    AppContext, Entity, ModelContext, ModelHandle, Task,
  11};
  12use language::{Chunk, Point};
  13use lazy_static::lazy_static;
  14use smol::future::yield_now;
  15use std::{cmp, collections::VecDeque, mem, ops::Range, time::Duration};
  16use sum_tree::{Bias, Cursor, SumTree};
  17use text::Patch;
  18
  19pub use super::tab_map::TextSummary;
  20pub type WrapEdit = text::Edit<u32>;
  21
  22pub struct WrapMap {
  23    snapshot: WrapSnapshot,
  24    pending_edits: VecDeque<(TabSnapshot, Vec<TabEdit>)>,
  25    interpolated_edits: Patch<u32>,
  26    edits_since_sync: Patch<u32>,
  27    wrap_width: Option<f32>,
  28    background_task: Option<Task<()>>,
  29    font: (FontId, f32),
  30}
  31
  32impl Entity for WrapMap {
  33    type Event = ();
  34}
  35
  36#[derive(Clone)]
  37pub struct WrapSnapshot {
  38    tab_snapshot: TabSnapshot,
  39    transforms: SumTree<Transform>,
  40    interpolated: bool,
  41}
  42
  43#[derive(Clone, Debug, Default, Eq, PartialEq)]
  44struct Transform {
  45    summary: TransformSummary,
  46    display_text: Option<&'static str>,
  47}
  48
  49#[derive(Clone, Debug, Default, Eq, PartialEq)]
  50struct TransformSummary {
  51    input: TextSummary,
  52    output: TextSummary,
  53}
  54
  55#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  56pub struct WrapPoint(pub Point);
  57
  58pub struct WrapChunks<'a> {
  59    input_chunks: tab_map::TabChunks<'a>,
  60    input_chunk: Chunk<'a>,
  61    output_position: WrapPoint,
  62    max_output_row: u32,
  63    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  64}
  65
  66#[derive(Clone)]
  67pub struct WrapBufferRows<'a> {
  68    input_buffer_rows: SuggestionBufferRows<'a>,
  69    input_buffer_row: Option<u32>,
  70    output_row: u32,
  71    soft_wrapped: bool,
  72    max_output_row: u32,
  73    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  74}
  75
  76impl WrapMap {
  77    pub fn new(
  78        tab_snapshot: TabSnapshot,
  79        font_id: FontId,
  80        font_size: f32,
  81        wrap_width: Option<f32>,
  82        cx: &mut AppContext,
  83    ) -> (ModelHandle<Self>, WrapSnapshot) {
  84        let handle = cx.add_model(|cx| {
  85            let mut this = Self {
  86                font: (font_id, font_size),
  87                wrap_width: None,
  88                pending_edits: Default::default(),
  89                interpolated_edits: Default::default(),
  90                edits_since_sync: Default::default(),
  91                snapshot: WrapSnapshot::new(tab_snapshot),
  92                background_task: None,
  93            };
  94            this.set_wrap_width(wrap_width, cx);
  95            mem::take(&mut this.edits_since_sync);
  96            this
  97        });
  98        let snapshot = handle.read(cx).snapshot.clone();
  99        (handle, snapshot)
 100    }
 101
 102    #[cfg(test)]
 103    pub fn is_rewrapping(&self) -> bool {
 104        self.background_task.is_some()
 105    }
 106
 107    pub fn sync(
 108        &mut self,
 109        tab_snapshot: TabSnapshot,
 110        edits: Vec<TabEdit>,
 111        cx: &mut ModelContext<Self>,
 112    ) -> (WrapSnapshot, Patch<u32>) {
 113        if self.wrap_width.is_some() {
 114            self.pending_edits.push_back((tab_snapshot, edits));
 115            self.flush_edits(cx);
 116        } else {
 117            self.edits_since_sync = self
 118                .edits_since_sync
 119                .compose(&self.snapshot.interpolate(tab_snapshot, &edits));
 120            self.snapshot.interpolated = false;
 121        }
 122
 123        (self.snapshot.clone(), mem::take(&mut self.edits_since_sync))
 124    }
 125
 126    pub fn set_font(
 127        &mut self,
 128        font_id: FontId,
 129        font_size: f32,
 130        cx: &mut ModelContext<Self>,
 131    ) -> bool {
 132        if (font_id, font_size) != self.font {
 133            self.font = (font_id, font_size);
 134            self.rewrap(cx);
 135            true
 136        } else {
 137            false
 138        }
 139    }
 140
 141    pub fn set_wrap_width(&mut self, wrap_width: Option<f32>, cx: &mut ModelContext<Self>) -> bool {
 142        if wrap_width == self.wrap_width {
 143            return false;
 144        }
 145
 146        self.wrap_width = wrap_width;
 147        self.rewrap(cx);
 148        true
 149    }
 150
 151    fn rewrap(&mut self, cx: &mut ModelContext<Self>) {
 152        self.background_task.take();
 153        self.interpolated_edits.clear();
 154        self.pending_edits.clear();
 155
 156        if let Some(wrap_width) = self.wrap_width {
 157            let mut new_snapshot = self.snapshot.clone();
 158            let font_cache = cx.font_cache().clone();
 159            let (font_id, font_size) = self.font;
 160            let task = cx.background().spawn(async move {
 161                let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 162                let tab_snapshot = new_snapshot.tab_snapshot.clone();
 163                let range = TabPoint::zero()..tab_snapshot.max_point();
 164                let edits = new_snapshot
 165                    .update(
 166                        tab_snapshot,
 167                        &[TabEdit {
 168                            old: range.clone(),
 169                            new: range.clone(),
 170                        }],
 171                        wrap_width,
 172                        &mut line_wrapper,
 173                    )
 174                    .await;
 175                (new_snapshot, edits)
 176            });
 177
 178            match cx
 179                .background()
 180                .block_with_timeout(Duration::from_millis(5), task)
 181            {
 182                Ok((snapshot, edits)) => {
 183                    self.snapshot = snapshot;
 184                    self.edits_since_sync = self.edits_since_sync.compose(&edits);
 185                    cx.notify();
 186                }
 187                Err(wrap_task) => {
 188                    self.background_task = Some(cx.spawn(|this, mut cx| async move {
 189                        let (snapshot, edits) = wrap_task.await;
 190                        this.update(&mut cx, |this, cx| {
 191                            this.snapshot = snapshot;
 192                            this.edits_since_sync = this
 193                                .edits_since_sync
 194                                .compose(mem::take(&mut this.interpolated_edits).invert())
 195                                .compose(&edits);
 196                            this.background_task = None;
 197                            this.flush_edits(cx);
 198                            cx.notify();
 199                        });
 200                    }));
 201                }
 202            }
 203        } else {
 204            let old_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 205            self.snapshot.transforms = SumTree::new();
 206            let summary = self.snapshot.tab_snapshot.text_summary();
 207            if !summary.lines.is_zero() {
 208                self.snapshot
 209                    .transforms
 210                    .push(Transform::isomorphic(summary), &());
 211            }
 212            let new_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 213            self.snapshot.interpolated = false;
 214            self.edits_since_sync = self.edits_since_sync.compose(&Patch::new(vec![WrapEdit {
 215                old: 0..old_rows,
 216                new: 0..new_rows,
 217            }]));
 218        }
 219    }
 220
 221    fn flush_edits(&mut self, cx: &mut ModelContext<Self>) {
 222        if !self.snapshot.interpolated {
 223            let mut to_remove_len = 0;
 224            for (tab_snapshot, _) in &self.pending_edits {
 225                if tab_snapshot.version <= self.snapshot.tab_snapshot.version {
 226                    to_remove_len += 1;
 227                } else {
 228                    break;
 229                }
 230            }
 231            self.pending_edits.drain(..to_remove_len);
 232        }
 233
 234        if self.pending_edits.is_empty() {
 235            return;
 236        }
 237
 238        if let Some(wrap_width) = self.wrap_width {
 239            if self.background_task.is_none() {
 240                let pending_edits = self.pending_edits.clone();
 241                let mut snapshot = self.snapshot.clone();
 242                let font_cache = cx.font_cache().clone();
 243                let (font_id, font_size) = self.font;
 244                let update_task = cx.background().spawn(async move {
 245                    let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 246
 247                    let mut edits = Patch::default();
 248                    for (tab_snapshot, tab_edits) in pending_edits {
 249                        let wrap_edits = snapshot
 250                            .update(tab_snapshot, &tab_edits, wrap_width, &mut line_wrapper)
 251                            .await;
 252                        edits = edits.compose(&wrap_edits);
 253                    }
 254                    (snapshot, edits)
 255                });
 256
 257                match cx
 258                    .background()
 259                    .block_with_timeout(Duration::from_millis(1), update_task)
 260                {
 261                    Ok((snapshot, output_edits)) => {
 262                        self.snapshot = snapshot;
 263                        self.edits_since_sync = self.edits_since_sync.compose(&output_edits);
 264                    }
 265                    Err(update_task) => {
 266                        self.background_task = Some(cx.spawn(|this, mut cx| async move {
 267                            let (snapshot, edits) = update_task.await;
 268                            this.update(&mut cx, |this, cx| {
 269                                this.snapshot = snapshot;
 270                                this.edits_since_sync = this
 271                                    .edits_since_sync
 272                                    .compose(mem::take(&mut this.interpolated_edits).invert())
 273                                    .compose(&edits);
 274                                this.background_task = None;
 275                                this.flush_edits(cx);
 276                                cx.notify();
 277                            });
 278                        }));
 279                    }
 280                }
 281            }
 282        }
 283
 284        let was_interpolated = self.snapshot.interpolated;
 285        let mut to_remove_len = 0;
 286        for (tab_snapshot, edits) in &self.pending_edits {
 287            if tab_snapshot.version <= self.snapshot.tab_snapshot.version {
 288                to_remove_len += 1;
 289            } else {
 290                let interpolated_edits = self.snapshot.interpolate(tab_snapshot.clone(), edits);
 291                self.edits_since_sync = self.edits_since_sync.compose(&interpolated_edits);
 292                self.interpolated_edits = self.interpolated_edits.compose(&interpolated_edits);
 293            }
 294        }
 295
 296        if !was_interpolated {
 297            self.pending_edits.drain(..to_remove_len);
 298        }
 299    }
 300}
 301
 302impl WrapSnapshot {
 303    fn new(tab_snapshot: TabSnapshot) -> Self {
 304        let mut transforms = SumTree::new();
 305        let extent = tab_snapshot.text_summary();
 306        if !extent.lines.is_zero() {
 307            transforms.push(Transform::isomorphic(extent), &());
 308        }
 309        Self {
 310            transforms,
 311            tab_snapshot,
 312            interpolated: true,
 313        }
 314    }
 315
 316    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
 317        self.tab_snapshot.buffer_snapshot()
 318    }
 319
 320    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
 321        let mut new_transforms;
 322        if tab_edits.is_empty() {
 323            new_transforms = self.transforms.clone();
 324        } else {
 325            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 326
 327            let mut tab_edits_iter = tab_edits.iter().peekable();
 328            new_transforms =
 329                old_cursor.slice(&tab_edits_iter.peek().unwrap().old.start, Bias::Right, &());
 330
 331            while let Some(edit) = tab_edits_iter.next() {
 332                if edit.new.start > TabPoint::from(new_transforms.summary().input.lines) {
 333                    let summary = new_tab_snapshot.text_summary_for_range(
 334                        TabPoint::from(new_transforms.summary().input.lines)..edit.new.start,
 335                    );
 336                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 337                }
 338
 339                if !edit.new.is_empty() {
 340                    new_transforms.push_or_extend(Transform::isomorphic(
 341                        new_tab_snapshot.text_summary_for_range(edit.new.clone()),
 342                    ));
 343                }
 344
 345                old_cursor.seek_forward(&edit.old.end, Bias::Right, &());
 346                if let Some(next_edit) = tab_edits_iter.peek() {
 347                    if next_edit.old.start > old_cursor.end(&()) {
 348                        if old_cursor.end(&()) > edit.old.end {
 349                            let summary = self
 350                                .tab_snapshot
 351                                .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 352                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 353                        }
 354
 355                        old_cursor.next(&());
 356                        new_transforms.push_tree(
 357                            old_cursor.slice(&next_edit.old.start, Bias::Right, &()),
 358                            &(),
 359                        );
 360                    }
 361                } else {
 362                    if old_cursor.end(&()) > edit.old.end {
 363                        let summary = self
 364                            .tab_snapshot
 365                            .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 366                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 367                    }
 368                    old_cursor.next(&());
 369                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 370                }
 371            }
 372        }
 373
 374        let old_snapshot = mem::replace(
 375            self,
 376            WrapSnapshot {
 377                tab_snapshot: new_tab_snapshot,
 378                transforms: new_transforms,
 379                interpolated: true,
 380            },
 381        );
 382        self.check_invariants();
 383        old_snapshot.compute_edits(tab_edits, self)
 384    }
 385
 386    async fn update(
 387        &mut self,
 388        new_tab_snapshot: TabSnapshot,
 389        tab_edits: &[TabEdit],
 390        wrap_width: f32,
 391        line_wrapper: &mut LineWrapper,
 392    ) -> Patch<u32> {
 393        #[derive(Debug)]
 394        struct RowEdit {
 395            old_rows: Range<u32>,
 396            new_rows: Range<u32>,
 397        }
 398
 399        let mut tab_edits_iter = tab_edits.iter().peekable();
 400        let mut row_edits = Vec::new();
 401        while let Some(edit) = tab_edits_iter.next() {
 402            let mut row_edit = RowEdit {
 403                old_rows: edit.old.start.row()..edit.old.end.row() + 1,
 404                new_rows: edit.new.start.row()..edit.new.end.row() + 1,
 405            };
 406
 407            while let Some(next_edit) = tab_edits_iter.peek() {
 408                if next_edit.old.start.row() <= row_edit.old_rows.end {
 409                    row_edit.old_rows.end = next_edit.old.end.row() + 1;
 410                    row_edit.new_rows.end = next_edit.new.end.row() + 1;
 411                    tab_edits_iter.next();
 412                } else {
 413                    break;
 414                }
 415            }
 416
 417            row_edits.push(row_edit);
 418        }
 419
 420        let mut new_transforms;
 421        if row_edits.is_empty() {
 422            new_transforms = self.transforms.clone();
 423        } else {
 424            let mut row_edits = row_edits.into_iter().peekable();
 425            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 426
 427            new_transforms = old_cursor.slice(
 428                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 429                Bias::Right,
 430                &(),
 431            );
 432
 433            while let Some(edit) = row_edits.next() {
 434                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 435                    let summary = new_tab_snapshot.text_summary_for_range(
 436                        TabPoint(new_transforms.summary().input.lines)
 437                            ..TabPoint::new(edit.new_rows.start, 0),
 438                    );
 439                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 440                }
 441
 442                let mut line = String::new();
 443                let mut remaining = None;
 444                let mut chunks = new_tab_snapshot.chunks(
 445                    TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point(),
 446                    false,
 447                    None,
 448                    None,
 449                );
 450                let mut edit_transforms = Vec::<Transform>::new();
 451                for _ in edit.new_rows.start..edit.new_rows.end {
 452                    while let Some(chunk) =
 453                        remaining.take().or_else(|| chunks.next().map(|c| c.text))
 454                    {
 455                        if let Some(ix) = chunk.find('\n') {
 456                            line.push_str(&chunk[..ix + 1]);
 457                            remaining = Some(&chunk[ix + 1..]);
 458                            break;
 459                        } else {
 460                            line.push_str(chunk)
 461                        }
 462                    }
 463
 464                    if line.is_empty() {
 465                        break;
 466                    }
 467
 468                    let mut prev_boundary_ix = 0;
 469                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 470                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 471                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 472                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 473                        prev_boundary_ix = boundary.ix;
 474                    }
 475
 476                    if prev_boundary_ix < line.len() {
 477                        push_isomorphic(
 478                            &mut edit_transforms,
 479                            TextSummary::from(&line[prev_boundary_ix..]),
 480                        );
 481                    }
 482
 483                    line.clear();
 484                    yield_now().await;
 485                }
 486
 487                let mut edit_transforms = edit_transforms.into_iter();
 488                if let Some(transform) = edit_transforms.next() {
 489                    new_transforms.push_or_extend(transform);
 490                }
 491                new_transforms.extend(edit_transforms, &());
 492
 493                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 494                if let Some(next_edit) = row_edits.peek() {
 495                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 496                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 497                            let summary = self.tab_snapshot.text_summary_for_range(
 498                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 499                            );
 500                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 501                        }
 502                        old_cursor.next(&());
 503                        new_transforms.push_tree(
 504                            old_cursor.slice(
 505                                &TabPoint::new(next_edit.old_rows.start, 0),
 506                                Bias::Right,
 507                                &(),
 508                            ),
 509                            &(),
 510                        );
 511                    }
 512                } else {
 513                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 514                        let summary = self.tab_snapshot.text_summary_for_range(
 515                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 516                        );
 517                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 518                    }
 519                    old_cursor.next(&());
 520                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 521                }
 522            }
 523        }
 524
 525        let old_snapshot = mem::replace(
 526            self,
 527            WrapSnapshot {
 528                tab_snapshot: new_tab_snapshot,
 529                transforms: new_transforms,
 530                interpolated: false,
 531            },
 532        );
 533        self.check_invariants();
 534        old_snapshot.compute_edits(tab_edits, self)
 535    }
 536
 537    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &WrapSnapshot) -> Patch<u32> {
 538        let mut wrap_edits = Vec::new();
 539        let mut old_cursor = self.transforms.cursor::<TransformSummary>();
 540        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
 541        for mut tab_edit in tab_edits.iter().cloned() {
 542            tab_edit.old.start.0.column = 0;
 543            tab_edit.old.end.0 += Point::new(1, 0);
 544            tab_edit.new.start.0.column = 0;
 545            tab_edit.new.end.0 += Point::new(1, 0);
 546
 547            old_cursor.seek(&tab_edit.old.start, Bias::Right, &());
 548            let mut old_start = old_cursor.start().output.lines;
 549            old_start += tab_edit.old.start.0 - old_cursor.start().input.lines;
 550
 551            old_cursor.seek(&tab_edit.old.end, Bias::Right, &());
 552            let mut old_end = old_cursor.start().output.lines;
 553            old_end += tab_edit.old.end.0 - old_cursor.start().input.lines;
 554
 555            new_cursor.seek(&tab_edit.new.start, Bias::Right, &());
 556            let mut new_start = new_cursor.start().output.lines;
 557            new_start += tab_edit.new.start.0 - new_cursor.start().input.lines;
 558
 559            new_cursor.seek(&tab_edit.new.end, Bias::Right, &());
 560            let mut new_end = new_cursor.start().output.lines;
 561            new_end += tab_edit.new.end.0 - new_cursor.start().input.lines;
 562
 563            wrap_edits.push(WrapEdit {
 564                old: old_start.row..old_end.row,
 565                new: new_start.row..new_end.row,
 566            });
 567        }
 568
 569        consolidate_wrap_edits(&mut wrap_edits);
 570        Patch::new(wrap_edits)
 571    }
 572
 573    pub fn chunks<'a>(
 574        &'a self,
 575        rows: Range<u32>,
 576        language_aware: bool,
 577        text_highlights: Option<&'a TextHighlights>,
 578        suggestion_highlight: Option<HighlightStyle>,
 579    ) -> WrapChunks<'a> {
 580        let output_start = WrapPoint::new(rows.start, 0);
 581        let output_end = WrapPoint::new(rows.end, 0);
 582        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 583        transforms.seek(&output_start, Bias::Right, &());
 584        let mut input_start = TabPoint(transforms.start().1 .0);
 585        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 586            input_start.0 += output_start.0 - transforms.start().0 .0;
 587        }
 588        let input_end = self
 589            .to_tab_point(output_end)
 590            .min(self.tab_snapshot.max_point());
 591        WrapChunks {
 592            input_chunks: self.tab_snapshot.chunks(
 593                input_start..input_end,
 594                language_aware,
 595                text_highlights,
 596                suggestion_highlight,
 597            ),
 598            input_chunk: Default::default(),
 599            output_position: output_start,
 600            max_output_row: rows.end,
 601            transforms,
 602        }
 603    }
 604
 605    pub fn max_point(&self) -> WrapPoint {
 606        WrapPoint(self.transforms.summary().output.lines)
 607    }
 608
 609    pub fn line_len(&self, row: u32) -> u32 {
 610        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 611        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Left, &());
 612        if cursor
 613            .item()
 614            .map_or(false, |transform| transform.is_isomorphic())
 615        {
 616            let overshoot = row - cursor.start().0.row();
 617            let tab_row = cursor.start().1.row() + overshoot;
 618            let tab_line_len = self.tab_snapshot.line_len(tab_row);
 619            if overshoot == 0 {
 620                cursor.start().0.column() + (tab_line_len - cursor.start().1.column())
 621            } else {
 622                tab_line_len
 623            }
 624        } else {
 625            cursor.start().0.column()
 626        }
 627    }
 628
 629    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 630        let mut cursor = self.transforms.cursor::<WrapPoint>();
 631        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 632        cursor.item().and_then(|transform| {
 633            if transform.is_isomorphic() {
 634                None
 635            } else {
 636                Some(transform.summary.output.lines.column)
 637            }
 638        })
 639    }
 640
 641    pub fn longest_row(&self) -> u32 {
 642        self.transforms.summary().output.longest_row
 643    }
 644
 645    pub fn buffer_rows(&self, start_row: u32) -> WrapBufferRows {
 646        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 647        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 648        let mut input_row = transforms.start().1.row();
 649        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 650            input_row += start_row - transforms.start().0.row();
 651        }
 652        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 653        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 654        let input_buffer_row = input_buffer_rows.next().unwrap();
 655        WrapBufferRows {
 656            transforms,
 657            input_buffer_row,
 658            input_buffer_rows,
 659            output_row: start_row,
 660            soft_wrapped,
 661            max_output_row: self.max_point().row(),
 662        }
 663    }
 664
 665    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 666        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 667        cursor.seek(&point, Bias::Right, &());
 668        let mut tab_point = cursor.start().1 .0;
 669        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 670            tab_point += point.0 - cursor.start().0 .0;
 671        }
 672        TabPoint(tab_point)
 673    }
 674
 675    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 676        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 677    }
 678
 679    pub fn make_wrap_point(&self, point: Point, bias: Bias) -> WrapPoint {
 680        self.tab_point_to_wrap_point(self.tab_snapshot.make_tab_point(point, bias))
 681    }
 682
 683    pub fn tab_point_to_wrap_point(&self, point: TabPoint) -> WrapPoint {
 684        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 685        cursor.seek(&point, Bias::Right, &());
 686        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 687    }
 688
 689    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 690        if bias == Bias::Left {
 691            let mut cursor = self.transforms.cursor::<WrapPoint>();
 692            cursor.seek(&point, Bias::Right, &());
 693            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 694                point = *cursor.start();
 695                *point.column_mut() -= 1;
 696            }
 697        }
 698
 699        self.tab_point_to_wrap_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 700    }
 701
 702    pub fn prev_row_boundary(&self, mut point: WrapPoint) -> u32 {
 703        if self.transforms.is_empty() {
 704            return 0;
 705        }
 706
 707        *point.column_mut() = 0;
 708
 709        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 710        cursor.seek(&point, Bias::Right, &());
 711        if cursor.item().is_none() {
 712            cursor.prev(&());
 713        }
 714
 715        while let Some(transform) = cursor.item() {
 716            if transform.is_isomorphic() && cursor.start().1.column() == 0 {
 717                return cmp::min(cursor.end(&()).0.row(), point.row());
 718            } else {
 719                cursor.prev(&());
 720            }
 721        }
 722
 723        unreachable!()
 724    }
 725
 726    pub fn next_row_boundary(&self, mut point: WrapPoint) -> Option<u32> {
 727        point.0 += Point::new(1, 0);
 728
 729        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 730        cursor.seek(&point, Bias::Right, &());
 731        while let Some(transform) = cursor.item() {
 732            if transform.is_isomorphic() && cursor.start().1.column() == 0 {
 733                return Some(cmp::max(cursor.start().0.row(), point.row()));
 734            } else {
 735                cursor.next(&());
 736            }
 737        }
 738
 739        None
 740    }
 741
 742    fn check_invariants(&self) {
 743        #[cfg(test)]
 744        {
 745            assert_eq!(
 746                TabPoint::from(self.transforms.summary().input.lines),
 747                self.tab_snapshot.max_point()
 748            );
 749
 750            {
 751                let mut transforms = self.transforms.cursor::<()>().peekable();
 752                while let Some(transform) = transforms.next() {
 753                    if let Some(next_transform) = transforms.peek() {
 754                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 755                    }
 756                }
 757            }
 758
 759            let text = language::Rope::from(self.text().as_str());
 760            let input_buffer_rows = self.buffer_snapshot().buffer_rows(0).collect::<Vec<_>>();
 761            let mut expected_buffer_rows = Vec::new();
 762            let mut prev_fold_row = 0;
 763            for display_row in 0..=self.max_point().row() {
 764                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 765                let suggestion_point = self
 766                    .tab_snapshot
 767                    .to_suggestion_point(tab_point, Bias::Left)
 768                    .0;
 769                let fold_point = self
 770                    .tab_snapshot
 771                    .suggestion_snapshot
 772                    .to_fold_point(suggestion_point);
 773                if fold_point.row() == prev_fold_row && display_row != 0 {
 774                    expected_buffer_rows.push(None);
 775                } else {
 776                    let buffer_point = fold_point
 777                        .to_buffer_point(&self.tab_snapshot.suggestion_snapshot.fold_snapshot);
 778                    expected_buffer_rows.push(input_buffer_rows[buffer_point.row as usize]);
 779                    prev_fold_row = fold_point.row();
 780                }
 781
 782                assert_eq!(self.line_len(display_row), text.line_len(display_row));
 783            }
 784
 785            for start_display_row in 0..expected_buffer_rows.len() {
 786                assert_eq!(
 787                    self.buffer_rows(start_display_row as u32)
 788                        .collect::<Vec<_>>(),
 789                    &expected_buffer_rows[start_display_row..],
 790                    "invalid buffer_rows({}..)",
 791                    start_display_row
 792                );
 793            }
 794        }
 795    }
 796}
 797
 798impl<'a> Iterator for WrapChunks<'a> {
 799    type Item = Chunk<'a>;
 800
 801    fn next(&mut self) -> Option<Self::Item> {
 802        if self.output_position.row() >= self.max_output_row {
 803            return None;
 804        }
 805
 806        let transform = self.transforms.item()?;
 807        if let Some(display_text) = transform.display_text {
 808            let mut start_ix = 0;
 809            let mut end_ix = display_text.len();
 810            let mut summary = transform.summary.output.lines;
 811
 812            if self.output_position > self.transforms.start().0 {
 813                // Exclude newline starting prior to the desired row.
 814                start_ix = 1;
 815                summary.row = 0;
 816            } else if self.output_position.row() + 1 >= self.max_output_row {
 817                // Exclude soft indentation ending after the desired row.
 818                end_ix = 1;
 819                summary.column = 0;
 820            }
 821
 822            self.output_position.0 += summary;
 823            self.transforms.next(&());
 824            return Some(Chunk {
 825                text: &display_text[start_ix..end_ix],
 826                ..self.input_chunk
 827            });
 828        }
 829
 830        if self.input_chunk.text.is_empty() {
 831            self.input_chunk = self.input_chunks.next().unwrap();
 832        }
 833
 834        let mut input_len = 0;
 835        let transform_end = self.transforms.end(&()).0;
 836        for c in self.input_chunk.text.chars() {
 837            let char_len = c.len_utf8();
 838            input_len += char_len;
 839            if c == '\n' {
 840                *self.output_position.row_mut() += 1;
 841                *self.output_position.column_mut() = 0;
 842            } else {
 843                *self.output_position.column_mut() += char_len as u32;
 844            }
 845
 846            if self.output_position >= transform_end {
 847                self.transforms.next(&());
 848                break;
 849            }
 850        }
 851
 852        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 853        self.input_chunk.text = suffix;
 854        Some(Chunk {
 855            text: prefix,
 856            ..self.input_chunk
 857        })
 858    }
 859}
 860
 861impl<'a> Iterator for WrapBufferRows<'a> {
 862    type Item = Option<u32>;
 863
 864    fn next(&mut self) -> Option<Self::Item> {
 865        if self.output_row > self.max_output_row {
 866            return None;
 867        }
 868
 869        let buffer_row = self.input_buffer_row;
 870        let soft_wrapped = self.soft_wrapped;
 871
 872        self.output_row += 1;
 873        self.transforms
 874            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 875        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 876            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 877            self.soft_wrapped = false;
 878        } else {
 879            self.soft_wrapped = true;
 880        }
 881
 882        Some(if soft_wrapped { None } else { buffer_row })
 883    }
 884}
 885
 886impl Transform {
 887    fn isomorphic(summary: TextSummary) -> Self {
 888        #[cfg(test)]
 889        assert!(!summary.lines.is_zero());
 890
 891        Self {
 892            summary: TransformSummary {
 893                input: summary.clone(),
 894                output: summary,
 895            },
 896            display_text: None,
 897        }
 898    }
 899
 900    fn wrap(indent: u32) -> Self {
 901        lazy_static! {
 902            static ref WRAP_TEXT: String = {
 903                let mut wrap_text = String::new();
 904                wrap_text.push('\n');
 905                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 906                wrap_text
 907            };
 908        }
 909
 910        Self {
 911            summary: TransformSummary {
 912                input: TextSummary::default(),
 913                output: TextSummary {
 914                    lines: Point::new(1, indent),
 915                    first_line_chars: 0,
 916                    last_line_chars: indent,
 917                    longest_row: 1,
 918                    longest_row_chars: indent,
 919                },
 920            },
 921            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 922        }
 923    }
 924
 925    fn is_isomorphic(&self) -> bool {
 926        self.display_text.is_none()
 927    }
 928}
 929
 930impl sum_tree::Item for Transform {
 931    type Summary = TransformSummary;
 932
 933    fn summary(&self) -> Self::Summary {
 934        self.summary.clone()
 935    }
 936}
 937
 938fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 939    if let Some(last_transform) = transforms.last_mut() {
 940        if last_transform.is_isomorphic() {
 941            last_transform.summary.input += &summary;
 942            last_transform.summary.output += &summary;
 943            return;
 944        }
 945    }
 946    transforms.push(Transform::isomorphic(summary));
 947}
 948
 949trait SumTreeExt {
 950    fn push_or_extend(&mut self, transform: Transform);
 951}
 952
 953impl SumTreeExt for SumTree<Transform> {
 954    fn push_or_extend(&mut self, transform: Transform) {
 955        let mut transform = Some(transform);
 956        self.update_last(
 957            |last_transform| {
 958                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
 959                    let transform = transform.take().unwrap();
 960                    last_transform.summary.input += &transform.summary.input;
 961                    last_transform.summary.output += &transform.summary.output;
 962                }
 963            },
 964            &(),
 965        );
 966
 967        if let Some(transform) = transform {
 968            self.push(transform, &());
 969        }
 970    }
 971}
 972
 973impl WrapPoint {
 974    pub fn new(row: u32, column: u32) -> Self {
 975        Self(Point::new(row, column))
 976    }
 977
 978    pub fn row(self) -> u32 {
 979        self.0.row
 980    }
 981
 982    pub fn row_mut(&mut self) -> &mut u32 {
 983        &mut self.0.row
 984    }
 985
 986    pub fn column(self) -> u32 {
 987        self.0.column
 988    }
 989
 990    pub fn column_mut(&mut self) -> &mut u32 {
 991        &mut self.0.column
 992    }
 993}
 994
 995impl sum_tree::Summary for TransformSummary {
 996    type Context = ();
 997
 998    fn add_summary(&mut self, other: &Self, _: &()) {
 999        self.input += &other.input;
1000        self.output += &other.output;
1001    }
1002}
1003
1004impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
1005    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1006        self.0 += summary.input.lines;
1007    }
1008}
1009
1010impl<'a> sum_tree::SeekTarget<'a, TransformSummary, TransformSummary> for TabPoint {
1011    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
1012        Ord::cmp(&self.0, &cursor_location.input.lines)
1013    }
1014}
1015
1016impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
1017    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1018        self.0 += summary.output.lines;
1019    }
1020}
1021
1022fn consolidate_wrap_edits(edits: &mut Vec<WrapEdit>) {
1023    let mut i = 1;
1024    while i < edits.len() {
1025        let edit = edits[i].clone();
1026        let prev_edit = &mut edits[i - 1];
1027        if prev_edit.old.end >= edit.old.start {
1028            prev_edit.old.end = edit.old.end;
1029            prev_edit.new.end = edit.new.end;
1030            edits.remove(i);
1031            continue;
1032        }
1033        i += 1;
1034    }
1035}
1036
1037#[cfg(test)]
1038mod tests {
1039    use super::*;
1040    use crate::{
1041        display_map::{fold_map::FoldMap, suggestion_map::SuggestionMap, tab_map::TabMap},
1042        MultiBuffer,
1043    };
1044    use gpui::test::observe;
1045    use rand::prelude::*;
1046    use settings::Settings;
1047    use smol::stream::StreamExt;
1048    use std::{cmp, env, num::NonZeroU32};
1049    use text::Rope;
1050
1051    #[gpui::test(iterations = 100)]
1052    async fn test_random_wraps(cx: &mut gpui::TestAppContext, mut rng: StdRng) {
1053        cx.update(|cx| cx.set_global(Settings::test(cx)));
1054        cx.foreground().set_block_on_ticks(0..=50);
1055        cx.foreground().forbid_parking();
1056        let operations = env::var("OPERATIONS")
1057            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1058            .unwrap_or(10);
1059
1060        let font_cache = cx.font_cache().clone();
1061        let font_system = cx.platform().fonts();
1062        let mut wrap_width = if rng.gen_bool(0.1) {
1063            None
1064        } else {
1065            Some(rng.gen_range(0.0..=1000.0))
1066        };
1067        let tab_size = NonZeroU32::new(rng.gen_range(1..=4)).unwrap();
1068        let family_id = font_cache
1069            .load_family(&["Helvetica"], &Default::default())
1070            .unwrap();
1071        let font_id = font_cache
1072            .select_font(family_id, &Default::default())
1073            .unwrap();
1074        let font_size = 14.0;
1075
1076        log::info!("Tab size: {}", tab_size);
1077        log::info!("Wrap width: {:?}", wrap_width);
1078
1079        let buffer = cx.update(|cx| {
1080            if rng.gen() {
1081                MultiBuffer::build_random(&mut rng, cx)
1082            } else {
1083                let len = rng.gen_range(0..10);
1084                let text = util::RandomCharIter::new(&mut rng)
1085                    .take(len)
1086                    .collect::<String>();
1087                MultiBuffer::build_simple(&text, cx)
1088            }
1089        });
1090        let mut buffer_snapshot = buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx));
1091        log::info!("Buffer text: {:?}", buffer_snapshot.text());
1092        let (mut fold_map, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
1093        log::info!("FoldMap text: {:?}", fold_snapshot.text());
1094        let (suggestion_map, suggestion_snapshot) = SuggestionMap::new(fold_snapshot.clone());
1095        log::info!("SuggestionMap text: {:?}", suggestion_snapshot.text());
1096        let (tab_map, _) = TabMap::new(suggestion_snapshot.clone(), tab_size);
1097        let tabs_snapshot = tab_map.set_max_expansion_column(32);
1098        log::info!("TabMap text: {:?}", tabs_snapshot.text());
1099
1100        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1101        let unwrapped_text = tabs_snapshot.text();
1102        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1103
1104        let (wrap_map, _) =
1105            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
1106        let mut notifications = observe(&wrap_map, cx);
1107
1108        if wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1109            notifications.next().await.unwrap();
1110        }
1111
1112        let (initial_snapshot, _) = wrap_map.update(cx, |map, cx| {
1113            assert!(!map.is_rewrapping());
1114            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1115        });
1116
1117        let actual_text = initial_snapshot.text();
1118        assert_eq!(
1119            actual_text, expected_text,
1120            "unwrapped text is: {:?}",
1121            unwrapped_text
1122        );
1123        log::info!("Wrapped text: {:?}", actual_text);
1124
1125        let mut edits = Vec::new();
1126        for _i in 0..operations {
1127            log::info!("{} ==============================================", _i);
1128
1129            let mut buffer_edits = Vec::new();
1130            match rng.gen_range(0..=100) {
1131                0..=19 => {
1132                    wrap_width = if rng.gen_bool(0.2) {
1133                        None
1134                    } else {
1135                        Some(rng.gen_range(0.0..=1000.0))
1136                    };
1137                    log::info!("Setting wrap width to {:?}", wrap_width);
1138                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1139                }
1140                20..=39 => {
1141                    for (fold_snapshot, fold_edits) in fold_map.randomly_mutate(&mut rng) {
1142                        let (suggestion_snapshot, suggestion_edits) =
1143                            suggestion_map.sync(fold_snapshot, fold_edits);
1144                        let (tabs_snapshot, tab_edits) =
1145                            tab_map.sync(suggestion_snapshot, suggestion_edits, tab_size);
1146                        let (mut snapshot, wrap_edits) =
1147                            wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1148                        snapshot.check_invariants();
1149                        snapshot.verify_chunks(&mut rng);
1150                        edits.push((snapshot, wrap_edits));
1151                    }
1152                }
1153                40..=59 => {
1154                    let (suggestion_snapshot, suggestion_edits) =
1155                        suggestion_map.randomly_mutate(&mut rng);
1156                    let (tabs_snapshot, tab_edits) =
1157                        tab_map.sync(suggestion_snapshot, suggestion_edits, tab_size);
1158                    let (mut snapshot, wrap_edits) =
1159                        wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1160                    snapshot.check_invariants();
1161                    snapshot.verify_chunks(&mut rng);
1162                    edits.push((snapshot, wrap_edits));
1163                }
1164                _ => {
1165                    buffer.update(cx, |buffer, cx| {
1166                        let subscription = buffer.subscribe();
1167                        let edit_count = rng.gen_range(1..=5);
1168                        buffer.randomly_mutate(&mut rng, edit_count, cx);
1169                        buffer_snapshot = buffer.snapshot(cx);
1170                        buffer_edits.extend(subscription.consume());
1171                    });
1172                }
1173            }
1174
1175            log::info!("Buffer text: {:?}", buffer_snapshot.text());
1176            let (fold_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1177            log::info!("FoldMap text: {:?}", fold_snapshot.text());
1178            let (suggestion_snapshot, suggestion_edits) =
1179                suggestion_map.sync(fold_snapshot, fold_edits);
1180            log::info!("SuggestionMap text: {:?}", suggestion_snapshot.text());
1181            let (tabs_snapshot, tab_edits) =
1182                tab_map.sync(suggestion_snapshot, suggestion_edits, tab_size);
1183            log::info!("TabMap text: {:?}", tabs_snapshot.text());
1184
1185            let unwrapped_text = tabs_snapshot.text();
1186            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1187            let (mut snapshot, wrap_edits) =
1188                wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot.clone(), tab_edits, cx));
1189            snapshot.check_invariants();
1190            snapshot.verify_chunks(&mut rng);
1191            edits.push((snapshot, wrap_edits));
1192
1193            if wrap_map.read_with(cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1194                log::info!("Waiting for wrapping to finish");
1195                while wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1196                    notifications.next().await.unwrap();
1197                }
1198                wrap_map.read_with(cx, |map, _| assert!(map.pending_edits.is_empty()));
1199            }
1200
1201            if !wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1202                let (mut wrapped_snapshot, wrap_edits) =
1203                    wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1204                let actual_text = wrapped_snapshot.text();
1205                let actual_longest_row = wrapped_snapshot.longest_row();
1206                log::info!("Wrapping finished: {:?}", actual_text);
1207                wrapped_snapshot.check_invariants();
1208                wrapped_snapshot.verify_chunks(&mut rng);
1209                edits.push((wrapped_snapshot.clone(), wrap_edits));
1210                assert_eq!(
1211                    actual_text, expected_text,
1212                    "unwrapped text is: {:?}",
1213                    unwrapped_text
1214                );
1215
1216                let mut summary = TextSummary::default();
1217                for (ix, item) in wrapped_snapshot
1218                    .transforms
1219                    .items(&())
1220                    .into_iter()
1221                    .enumerate()
1222                {
1223                    summary += &item.summary.output;
1224                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1225                }
1226
1227                if tab_size.get() == 1
1228                    || !wrapped_snapshot
1229                        .tab_snapshot
1230                        .suggestion_snapshot
1231                        .text()
1232                        .contains('\t')
1233                {
1234                    let mut expected_longest_rows = Vec::new();
1235                    let mut longest_line_len = -1;
1236                    for (row, line) in expected_text.split('\n').enumerate() {
1237                        let line_char_count = line.chars().count() as isize;
1238                        if line_char_count > longest_line_len {
1239                            expected_longest_rows.clear();
1240                            longest_line_len = line_char_count;
1241                        }
1242                        if line_char_count >= longest_line_len {
1243                            expected_longest_rows.push(row as u32);
1244                        }
1245                    }
1246
1247                    assert!(
1248                        expected_longest_rows.contains(&actual_longest_row),
1249                        "incorrect longest row {}. expected {:?} with length {}",
1250                        actual_longest_row,
1251                        expected_longest_rows,
1252                        longest_line_len,
1253                    )
1254                }
1255            }
1256        }
1257
1258        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1259        for (snapshot, patch) in edits {
1260            let snapshot_text = Rope::from(snapshot.text().as_str());
1261            for edit in &patch {
1262                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1263                let old_end = initial_text.point_to_offset(cmp::min(
1264                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1265                    initial_text.max_point(),
1266                ));
1267                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1268                let new_end = snapshot_text.point_to_offset(cmp::min(
1269                    Point::new(edit.new.end, 0),
1270                    snapshot_text.max_point(),
1271                ));
1272                let new_text = snapshot_text
1273                    .chunks_in_range(new_start..new_end)
1274                    .collect::<String>();
1275
1276                initial_text.replace(old_start..old_end, &new_text);
1277            }
1278            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1279        }
1280
1281        if wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1282            log::info!("Waiting for wrapping to finish");
1283            while wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1284                notifications.next().await.unwrap();
1285            }
1286        }
1287        wrap_map.read_with(cx, |map, _| assert!(map.pending_edits.is_empty()));
1288    }
1289
1290    fn wrap_text(
1291        unwrapped_text: &str,
1292        wrap_width: Option<f32>,
1293        line_wrapper: &mut LineWrapper,
1294    ) -> String {
1295        if let Some(wrap_width) = wrap_width {
1296            let mut wrapped_text = String::new();
1297            for (row, line) in unwrapped_text.split('\n').enumerate() {
1298                if row > 0 {
1299                    wrapped_text.push('\n')
1300                }
1301
1302                let mut prev_ix = 0;
1303                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1304                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1305                    wrapped_text.push('\n');
1306                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1307                    prev_ix = boundary.ix;
1308                }
1309                wrapped_text.push_str(&line[prev_ix..]);
1310            }
1311            wrapped_text
1312        } else {
1313            unwrapped_text.to_string()
1314        }
1315    }
1316
1317    impl WrapSnapshot {
1318        pub fn text(&self) -> String {
1319            self.text_chunks(0).collect()
1320        }
1321
1322        pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
1323            self.chunks(wrap_row..self.max_point().row() + 1, false, None, None)
1324                .map(|h| h.text)
1325        }
1326
1327        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1328            for _ in 0..5 {
1329                let mut end_row = rng.gen_range(0..=self.max_point().row());
1330                let start_row = rng.gen_range(0..=end_row);
1331                end_row += 1;
1332
1333                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1334                if expected_text.ends_with('\n') {
1335                    expected_text.push('\n');
1336                }
1337                let mut expected_text = expected_text
1338                    .lines()
1339                    .take((end_row - start_row) as usize)
1340                    .collect::<Vec<_>>()
1341                    .join("\n");
1342                if end_row <= self.max_point().row() {
1343                    expected_text.push('\n');
1344                }
1345
1346                let actual_text = self
1347                    .chunks(start_row..end_row, true, None, None)
1348                    .map(|c| c.text)
1349                    .collect::<String>();
1350                assert_eq!(
1351                    expected_text,
1352                    actual_text,
1353                    "chunks != highlighted_chunks for rows {:?}",
1354                    start_row..end_row
1355                );
1356            }
1357        }
1358    }
1359}