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