tab_map.rs

  1use super::{
  2    suggestion_map::{self, SuggestionChunks, SuggestionEdit, SuggestionPoint, SuggestionSnapshot},
  3    TextHighlights,
  4};
  5use crate::MultiBufferSnapshot;
  6use language::{Chunk, Point};
  7use parking_lot::Mutex;
  8use std::{cmp, mem, num::NonZeroU32, ops::Range};
  9use sum_tree::Bias;
 10
 11const MAX_EXPANSION_COLUMN: u32 = 256;
 12
 13pub struct TabMap(Mutex<TabSnapshot>);
 14
 15impl TabMap {
 16    pub fn new(input: SuggestionSnapshot, tab_size: NonZeroU32) -> (Self, TabSnapshot) {
 17        let snapshot = TabSnapshot {
 18            suggestion_snapshot: input,
 19            tab_size,
 20            max_expansion_column: MAX_EXPANSION_COLUMN,
 21            version: 0,
 22        };
 23        (Self(Mutex::new(snapshot.clone())), snapshot)
 24    }
 25
 26    #[cfg(test)]
 27    pub fn set_max_expansion_column(&self, column: u32) -> TabSnapshot {
 28        self.0.lock().max_expansion_column = column;
 29        self.0.lock().clone()
 30    }
 31
 32    pub fn sync(
 33        &self,
 34        suggestion_snapshot: SuggestionSnapshot,
 35        mut suggestion_edits: Vec<SuggestionEdit>,
 36        tab_size: NonZeroU32,
 37    ) -> (TabSnapshot, Vec<TabEdit>) {
 38        let mut old_snapshot = self.0.lock();
 39        let mut new_snapshot = TabSnapshot {
 40            suggestion_snapshot,
 41            tab_size,
 42            max_expansion_column: old_snapshot.max_expansion_column,
 43            version: old_snapshot.version,
 44        };
 45
 46        if old_snapshot.suggestion_snapshot.version != new_snapshot.suggestion_snapshot.version {
 47            new_snapshot.version += 1;
 48        }
 49
 50        let old_max_offset = old_snapshot.suggestion_snapshot.len();
 51        let mut tab_edits = Vec::with_capacity(suggestion_edits.len());
 52
 53        if old_snapshot.tab_size == new_snapshot.tab_size {
 54            // Expand each edit to include the next tab on the same line as the edit,
 55            // and any subsequent tabs on that line that moved across the tab expansion
 56            // boundary.
 57            for suggestion_edit in &mut suggestion_edits {
 58                let old_end_column = old_snapshot
 59                    .suggestion_snapshot
 60                    .to_point(suggestion_edit.old.end)
 61                    .column();
 62                let new_end_column = new_snapshot
 63                    .suggestion_snapshot
 64                    .to_point(suggestion_edit.new.end)
 65                    .column();
 66
 67                let mut offset_from_edit = 0;
 68                let mut first_tab_offset = None;
 69                let mut last_tab_with_changed_expansion_offset = None;
 70                'outer: for chunk in old_snapshot.suggestion_snapshot.chunks(
 71                    suggestion_edit.old.end..old_max_offset,
 72                    false,
 73                    None,
 74                ) {
 75                    for (ix, mat) in chunk.text.match_indices(&['\t', '\n']) {
 76                        let offset_from_edit = offset_from_edit + (ix as u32);
 77                        match mat {
 78                            "\t" => {
 79                                if first_tab_offset.is_none() {
 80                                    first_tab_offset = Some(offset_from_edit);
 81                                }
 82
 83                                let old_column = old_end_column + offset_from_edit;
 84                                let new_column = new_end_column + offset_from_edit;
 85                                let was_expanded = old_column < old_snapshot.max_expansion_column;
 86                                let is_expanded = new_column < new_snapshot.max_expansion_column;
 87                                if was_expanded != is_expanded {
 88                                    last_tab_with_changed_expansion_offset = Some(offset_from_edit);
 89                                } else if !was_expanded && !is_expanded {
 90                                    break 'outer;
 91                                }
 92                            }
 93                            "\n" => break 'outer,
 94                            _ => unreachable!(),
 95                        }
 96                    }
 97
 98                    offset_from_edit += chunk.text.len() as u32;
 99                    if old_end_column + offset_from_edit >= old_snapshot.max_expansion_column
100                        && new_end_column | offset_from_edit >= new_snapshot.max_expansion_column
101                    {
102                        break;
103                    }
104                }
105
106                if let Some(offset) = last_tab_with_changed_expansion_offset.or(first_tab_offset) {
107                    suggestion_edit.old.end.0 += offset as usize + 1;
108                    suggestion_edit.new.end.0 += offset as usize + 1;
109                }
110            }
111
112            // Combine any edits that overlap due to the expansion.
113            let mut ix = 1;
114            while ix < suggestion_edits.len() {
115                let (prev_edits, next_edits) = suggestion_edits.split_at_mut(ix);
116                let prev_edit = prev_edits.last_mut().unwrap();
117                let edit = &next_edits[0];
118                if prev_edit.old.end >= edit.old.start {
119                    prev_edit.old.end = edit.old.end;
120                    prev_edit.new.end = edit.new.end;
121                    suggestion_edits.remove(ix);
122                } else {
123                    ix += 1;
124                }
125            }
126
127            for suggestion_edit in suggestion_edits {
128                let old_start = old_snapshot
129                    .suggestion_snapshot
130                    .to_point(suggestion_edit.old.start);
131                let old_end = old_snapshot
132                    .suggestion_snapshot
133                    .to_point(suggestion_edit.old.end);
134                let new_start = new_snapshot
135                    .suggestion_snapshot
136                    .to_point(suggestion_edit.new.start);
137                let new_end = new_snapshot
138                    .suggestion_snapshot
139                    .to_point(suggestion_edit.new.end);
140                tab_edits.push(TabEdit {
141                    old: old_snapshot.to_tab_point(old_start)..old_snapshot.to_tab_point(old_end),
142                    new: new_snapshot.to_tab_point(new_start)..new_snapshot.to_tab_point(new_end),
143                });
144            }
145        } else {
146            new_snapshot.version += 1;
147            tab_edits.push(TabEdit {
148                old: TabPoint::zero()..old_snapshot.max_point(),
149                new: TabPoint::zero()..new_snapshot.max_point(),
150            });
151        }
152
153        *old_snapshot = new_snapshot;
154        (old_snapshot.clone(), tab_edits)
155    }
156}
157
158#[derive(Clone)]
159pub struct TabSnapshot {
160    pub suggestion_snapshot: SuggestionSnapshot,
161    pub tab_size: NonZeroU32,
162    pub max_expansion_column: u32,
163    pub version: usize,
164}
165
166impl TabSnapshot {
167    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
168        self.suggestion_snapshot.buffer_snapshot()
169    }
170
171    pub fn line_len(&self, row: u32) -> u32 {
172        let max_point = self.max_point();
173        if row < max_point.row() {
174            self.to_tab_point(SuggestionPoint::new(
175                row,
176                self.suggestion_snapshot.line_len(row),
177            ))
178            .0
179            .column
180        } else {
181            max_point.column()
182        }
183    }
184
185    pub fn text_summary(&self) -> TextSummary {
186        self.text_summary_for_range(TabPoint::zero()..self.max_point())
187    }
188
189    pub fn text_summary_for_range(&self, range: Range<TabPoint>) -> TextSummary {
190        let input_start = self.to_suggestion_point(range.start, Bias::Left).0;
191        let input_end = self.to_suggestion_point(range.end, Bias::Right).0;
192        let input_summary = self
193            .suggestion_snapshot
194            .text_summary_for_range(input_start..input_end);
195
196        let mut first_line_chars = 0;
197        let line_end = if range.start.row() == range.end.row() {
198            range.end
199        } else {
200            self.max_point()
201        };
202        for c in self
203            .chunks(range.start..line_end, false, None)
204            .flat_map(|chunk| chunk.text.chars())
205        {
206            if c == '\n' {
207                break;
208            }
209            first_line_chars += 1;
210        }
211
212        let mut last_line_chars = 0;
213        if range.start.row() == range.end.row() {
214            last_line_chars = first_line_chars;
215        } else {
216            for _ in self
217                .chunks(TabPoint::new(range.end.row(), 0)..range.end, false, None)
218                .flat_map(|chunk| chunk.text.chars())
219            {
220                last_line_chars += 1;
221            }
222        }
223
224        TextSummary {
225            lines: range.end.0 - range.start.0,
226            first_line_chars,
227            last_line_chars,
228            longest_row: input_summary.longest_row,
229            longest_row_chars: input_summary.longest_row_chars,
230        }
231    }
232
233    pub fn chunks<'a>(
234        &'a self,
235        range: Range<TabPoint>,
236        language_aware: bool,
237        text_highlights: Option<&'a TextHighlights>,
238    ) -> TabChunks<'a> {
239        let (input_start, expanded_char_column, to_next_stop) =
240            self.to_suggestion_point(range.start, Bias::Left);
241        let input_column = input_start.column();
242        let input_start = self.suggestion_snapshot.to_offset(input_start);
243        let input_end = self
244            .suggestion_snapshot
245            .to_offset(self.to_suggestion_point(range.end, Bias::Right).0);
246        let to_next_stop = if range.start.0 + Point::new(0, to_next_stop) > range.end.0 {
247            range.end.column() - range.start.column()
248        } else {
249            to_next_stop
250        };
251
252        TabChunks {
253            suggestion_chunks: self.suggestion_snapshot.chunks(
254                input_start..input_end,
255                language_aware,
256                text_highlights,
257            ),
258            input_column,
259            column: expanded_char_column,
260            max_expansion_column: self.max_expansion_column,
261            output_position: range.start.0,
262            max_output_position: range.end.0,
263            tab_size: self.tab_size,
264            chunk: Chunk {
265                text: &SPACES[0..(to_next_stop as usize)],
266                ..Default::default()
267            },
268            inside_leading_tab: to_next_stop > 0,
269        }
270    }
271
272    pub fn buffer_rows(&self, row: u32) -> suggestion_map::SuggestionBufferRows {
273        self.suggestion_snapshot.buffer_rows(row)
274    }
275
276    #[cfg(test)]
277    pub fn text(&self) -> String {
278        self.chunks(TabPoint::zero()..self.max_point(), false, None)
279            .map(|chunk| chunk.text)
280            .collect()
281    }
282
283    pub fn max_point(&self) -> TabPoint {
284        self.to_tab_point(self.suggestion_snapshot.max_point())
285    }
286
287    pub fn clip_point(&self, point: TabPoint, bias: Bias) -> TabPoint {
288        self.to_tab_point(
289            self.suggestion_snapshot
290                .clip_point(self.to_suggestion_point(point, bias).0, bias),
291        )
292    }
293
294    pub fn to_tab_point(&self, input: SuggestionPoint) -> TabPoint {
295        let chars = self
296            .suggestion_snapshot
297            .chars_at(SuggestionPoint::new(input.row(), 0));
298        let expanded = self.expand_tabs(chars, input.column());
299        TabPoint::new(input.row(), expanded)
300    }
301
302    pub fn to_suggestion_point(&self, output: TabPoint, bias: Bias) -> (SuggestionPoint, u32, u32) {
303        let chars = self
304            .suggestion_snapshot
305            .chars_at(SuggestionPoint::new(output.row(), 0));
306        let expanded = output.column();
307        let (collapsed, expanded_char_column, to_next_stop) =
308            self.collapse_tabs(chars, expanded, bias);
309        (
310            SuggestionPoint::new(output.row(), collapsed as u32),
311            expanded_char_column,
312            to_next_stop,
313        )
314    }
315
316    pub fn make_tab_point(&self, point: Point, bias: Bias) -> TabPoint {
317        let fold_point = self
318            .suggestion_snapshot
319            .fold_snapshot
320            .to_fold_point(point, bias);
321        let suggestion_point = self.suggestion_snapshot.to_suggestion_point(fold_point);
322        self.to_tab_point(suggestion_point)
323    }
324
325    pub fn to_point(&self, point: TabPoint, bias: Bias) -> Point {
326        let suggestion_point = self.to_suggestion_point(point, bias).0;
327        let fold_point = self.suggestion_snapshot.to_fold_point(suggestion_point);
328        fold_point.to_buffer_point(&self.suggestion_snapshot.fold_snapshot)
329    }
330
331    fn expand_tabs(&self, chars: impl Iterator<Item = char>, column: u32) -> u32 {
332        let tab_size = self.tab_size.get();
333
334        let mut expanded_chars = 0;
335        let mut expanded_bytes = 0;
336        let mut collapsed_bytes = 0;
337        let end_column = column.min(self.max_expansion_column);
338        for c in chars {
339            if collapsed_bytes >= end_column {
340                break;
341            }
342            if c == '\t' {
343                let tab_len = tab_size - expanded_chars % tab_size;
344                expanded_bytes += tab_len;
345                expanded_chars += tab_len;
346            } else {
347                expanded_bytes += c.len_utf8() as u32;
348                expanded_chars += 1;
349            }
350            collapsed_bytes += c.len_utf8() as u32;
351        }
352        expanded_bytes + column.saturating_sub(collapsed_bytes)
353    }
354
355    fn collapse_tabs(
356        &self,
357        chars: impl Iterator<Item = char>,
358        column: u32,
359        bias: Bias,
360    ) -> (u32, u32, u32) {
361        let tab_size = self.tab_size.get();
362
363        let mut expanded_bytes = 0;
364        let mut expanded_chars = 0;
365        let mut collapsed_bytes = 0;
366        for c in chars {
367            if expanded_bytes >= column {
368                break;
369            }
370            if collapsed_bytes >= self.max_expansion_column {
371                break;
372            }
373
374            if c == '\t' {
375                let tab_len = tab_size - (expanded_chars % tab_size);
376                expanded_chars += tab_len;
377                expanded_bytes += tab_len;
378                if expanded_bytes > column {
379                    expanded_chars -= expanded_bytes - column;
380                    return match bias {
381                        Bias::Left => (collapsed_bytes, expanded_chars, expanded_bytes - column),
382                        Bias::Right => (collapsed_bytes + 1, expanded_chars, 0),
383                    };
384                }
385            } else {
386                expanded_chars += 1;
387                expanded_bytes += c.len_utf8() as u32;
388            }
389
390            if expanded_bytes > column && matches!(bias, Bias::Left) {
391                expanded_chars -= 1;
392                break;
393            }
394
395            collapsed_bytes += c.len_utf8() as u32;
396        }
397        (
398            collapsed_bytes + column.saturating_sub(expanded_bytes),
399            expanded_chars,
400            0,
401        )
402    }
403}
404
405#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
406pub struct TabPoint(pub Point);
407
408impl TabPoint {
409    pub fn new(row: u32, column: u32) -> Self {
410        Self(Point::new(row, column))
411    }
412
413    pub fn zero() -> Self {
414        Self::new(0, 0)
415    }
416
417    pub fn row(self) -> u32 {
418        self.0.row
419    }
420
421    pub fn column(self) -> u32 {
422        self.0.column
423    }
424}
425
426impl From<Point> for TabPoint {
427    fn from(point: Point) -> Self {
428        Self(point)
429    }
430}
431
432pub type TabEdit = text::Edit<TabPoint>;
433
434#[derive(Clone, Debug, Default, Eq, PartialEq)]
435pub struct TextSummary {
436    pub lines: Point,
437    pub first_line_chars: u32,
438    pub last_line_chars: u32,
439    pub longest_row: u32,
440    pub longest_row_chars: u32,
441}
442
443impl<'a> From<&'a str> for TextSummary {
444    fn from(text: &'a str) -> Self {
445        let sum = text::TextSummary::from(text);
446
447        TextSummary {
448            lines: sum.lines,
449            first_line_chars: sum.first_line_chars,
450            last_line_chars: sum.last_line_chars,
451            longest_row: sum.longest_row,
452            longest_row_chars: sum.longest_row_chars,
453        }
454    }
455}
456
457impl<'a> std::ops::AddAssign<&'a Self> for TextSummary {
458    fn add_assign(&mut self, other: &'a Self) {
459        let joined_chars = self.last_line_chars + other.first_line_chars;
460        if joined_chars > self.longest_row_chars {
461            self.longest_row = self.lines.row;
462            self.longest_row_chars = joined_chars;
463        }
464        if other.longest_row_chars > self.longest_row_chars {
465            self.longest_row = self.lines.row + other.longest_row;
466            self.longest_row_chars = other.longest_row_chars;
467        }
468
469        if self.lines.row == 0 {
470            self.first_line_chars += other.first_line_chars;
471        }
472
473        if other.lines.row == 0 {
474            self.last_line_chars += other.first_line_chars;
475        } else {
476            self.last_line_chars = other.last_line_chars;
477        }
478
479        self.lines += &other.lines;
480    }
481}
482
483// Handles a tab width <= 16
484const SPACES: &str = "                ";
485
486pub struct TabChunks<'a> {
487    suggestion_chunks: SuggestionChunks<'a>,
488    chunk: Chunk<'a>,
489    column: u32,
490    max_expansion_column: u32,
491    output_position: Point,
492    input_column: u32,
493    max_output_position: Point,
494    tab_size: NonZeroU32,
495    inside_leading_tab: bool,
496}
497
498impl<'a> Iterator for TabChunks<'a> {
499    type Item = Chunk<'a>;
500
501    fn next(&mut self) -> Option<Self::Item> {
502        if self.chunk.text.is_empty() {
503            if let Some(chunk) = self.suggestion_chunks.next() {
504                self.chunk = chunk;
505                if self.inside_leading_tab {
506                    self.chunk.text = &self.chunk.text[1..];
507                    self.inside_leading_tab = false;
508                    self.input_column += 1;
509                }
510            } else {
511                return None;
512            }
513        }
514
515        for (ix, c) in self.chunk.text.char_indices() {
516            match c {
517                '\t' => {
518                    if ix > 0 {
519                        let (prefix, suffix) = self.chunk.text.split_at(ix);
520                        self.chunk.text = suffix;
521                        return Some(Chunk {
522                            text: prefix,
523                            ..self.chunk
524                        });
525                    } else {
526                        self.chunk.text = &self.chunk.text[1..];
527                        let tab_size = if self.input_column < self.max_expansion_column {
528                            self.tab_size.get() as u32
529                        } else {
530                            1
531                        };
532                        let mut len = tab_size - self.column % tab_size;
533                        let next_output_position = cmp::min(
534                            self.output_position + Point::new(0, len),
535                            self.max_output_position,
536                        );
537                        len = next_output_position.column - self.output_position.column;
538                        self.column += len;
539                        self.input_column += 1;
540                        self.output_position = next_output_position;
541                        return Some(Chunk {
542                            text: &SPACES[..len as usize],
543                            ..self.chunk
544                        });
545                    }
546                }
547                '\n' => {
548                    self.column = 0;
549                    self.input_column = 0;
550                    self.output_position += Point::new(1, 0);
551                }
552                _ => {
553                    self.column += 1;
554                    if !self.inside_leading_tab {
555                        self.input_column += c.len_utf8() as u32;
556                    }
557                    self.output_position.column += c.len_utf8() as u32;
558                }
559            }
560        }
561
562        Some(mem::take(&mut self.chunk))
563    }
564}
565
566#[cfg(test)]
567mod tests {
568    use super::*;
569    use crate::{
570        display_map::{fold_map::FoldMap, suggestion_map::SuggestionMap},
571        MultiBuffer,
572    };
573    use rand::{prelude::StdRng, Rng};
574
575    #[gpui::test]
576    fn test_expand_tabs(cx: &mut gpui::MutableAppContext) {
577        let buffer = MultiBuffer::build_simple("", cx);
578        let buffer_snapshot = buffer.read(cx).snapshot(cx);
579        let (_, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
580        let (_, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
581        let (_, tab_snapshot) = TabMap::new(suggestion_snapshot, 4.try_into().unwrap());
582
583        assert_eq!(tab_snapshot.expand_tabs("\t".chars(), 0), 0);
584        assert_eq!(tab_snapshot.expand_tabs("\t".chars(), 1), 4);
585        assert_eq!(tab_snapshot.expand_tabs("\ta".chars(), 2), 5);
586    }
587
588    #[gpui::test]
589    fn test_long_lines(cx: &mut gpui::MutableAppContext) {
590        let max_expansion_column = 12;
591        let input = "A\tBC\tDEF\tG\tHI\tJ\tK\tL\tM";
592        let output = "A   BC  DEF G   HI J K L M";
593
594        let buffer = MultiBuffer::build_simple(input, cx);
595        let buffer_snapshot = buffer.read(cx).snapshot(cx);
596        let (_, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
597        let (_, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
598        let (_, mut tab_snapshot) = TabMap::new(suggestion_snapshot, 4.try_into().unwrap());
599
600        tab_snapshot.max_expansion_column = max_expansion_column;
601        assert_eq!(tab_snapshot.text(), output);
602
603        for (ix, c) in input.char_indices() {
604            assert_eq!(
605                tab_snapshot
606                    .chunks(
607                        TabPoint::new(0, ix as u32)..tab_snapshot.max_point(),
608                        false,
609                        None
610                    )
611                    .map(|c| c.text)
612                    .collect::<String>(),
613                &output[ix..],
614                "text from index {ix}"
615            );
616
617            if c != '\t' {
618                let input_point = Point::new(0, ix as u32);
619                let output_point = Point::new(0, output.find(c).unwrap() as u32);
620                assert_eq!(
621                    tab_snapshot.to_tab_point(SuggestionPoint(input_point)),
622                    TabPoint(output_point),
623                    "to_tab_point({input_point:?})"
624                );
625                assert_eq!(
626                    tab_snapshot
627                        .to_suggestion_point(TabPoint(output_point), Bias::Left)
628                        .0,
629                    SuggestionPoint(input_point),
630                    "to_suggestion_point({output_point:?})"
631                );
632            }
633        }
634    }
635
636    #[gpui::test]
637    fn test_long_lines_with_character_spanning_max_expansion_column(
638        cx: &mut gpui::MutableAppContext,
639    ) {
640        let max_expansion_column = 8;
641        let input = "abcdefg⋯hij";
642
643        let buffer = MultiBuffer::build_simple(input, cx);
644        let buffer_snapshot = buffer.read(cx).snapshot(cx);
645        let (_, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
646        let (_, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
647        let (_, mut tab_snapshot) = TabMap::new(suggestion_snapshot, 4.try_into().unwrap());
648
649        tab_snapshot.max_expansion_column = max_expansion_column;
650        assert_eq!(tab_snapshot.text(), input);
651    }
652
653    #[gpui::test(iterations = 100)]
654    fn test_random_tabs(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
655        let tab_size = NonZeroU32::new(rng.gen_range(1..=4)).unwrap();
656        let len = rng.gen_range(0..30);
657        let buffer = if rng.gen() {
658            let text = util::RandomCharIter::new(&mut rng)
659                .take(len)
660                .collect::<String>();
661            MultiBuffer::build_simple(&text, cx)
662        } else {
663            MultiBuffer::build_random(&mut rng, cx)
664        };
665        let buffer_snapshot = buffer.read(cx).snapshot(cx);
666        log::info!("Buffer text: {:?}", buffer_snapshot.text());
667
668        let (mut fold_map, _) = FoldMap::new(buffer_snapshot.clone());
669        fold_map.randomly_mutate(&mut rng);
670        let (fold_snapshot, _) = fold_map.read(buffer_snapshot, vec![]);
671        log::info!("FoldMap text: {:?}", fold_snapshot.text());
672        let (suggestion_map, _) = SuggestionMap::new(fold_snapshot);
673        let (suggestion_snapshot, _) = suggestion_map.randomly_mutate(&mut rng);
674        log::info!("SuggestionMap text: {:?}", suggestion_snapshot.text());
675
676        let (tab_map, _) = TabMap::new(suggestion_snapshot.clone(), tab_size);
677        let tabs_snapshot = tab_map.set_max_expansion_column(32);
678
679        let text = text::Rope::from(tabs_snapshot.text().as_str());
680        log::info!(
681            "TabMap text (tab size: {}): {:?}",
682            tab_size,
683            tabs_snapshot.text(),
684        );
685
686        for _ in 0..5 {
687            let end_row = rng.gen_range(0..=text.max_point().row);
688            let end_column = rng.gen_range(0..=text.line_len(end_row));
689            let mut end = TabPoint(text.clip_point(Point::new(end_row, end_column), Bias::Right));
690            let start_row = rng.gen_range(0..=text.max_point().row);
691            let start_column = rng.gen_range(0..=text.line_len(start_row));
692            let mut start =
693                TabPoint(text.clip_point(Point::new(start_row, start_column), Bias::Left));
694            if start > end {
695                mem::swap(&mut start, &mut end);
696            }
697
698            let expected_text = text
699                .chunks_in_range(text.point_to_offset(start.0)..text.point_to_offset(end.0))
700                .collect::<String>();
701            let expected_summary = TextSummary::from(expected_text.as_str());
702            assert_eq!(
703                tabs_snapshot
704                    .chunks(start..end, false, None)
705                    .map(|c| c.text)
706                    .collect::<String>(),
707                expected_text,
708                "chunks({:?}..{:?})",
709                start,
710                end
711            );
712
713            let mut actual_summary = tabs_snapshot.text_summary_for_range(start..end);
714            if tab_size.get() > 1 && suggestion_snapshot.text().contains('\t') {
715                actual_summary.longest_row = expected_summary.longest_row;
716                actual_summary.longest_row_chars = expected_summary.longest_row_chars;
717            }
718            assert_eq!(actual_summary, expected_summary);
719        }
720
721        for row in 0..=text.max_point().row {
722            assert_eq!(
723                tabs_snapshot.line_len(row),
724                text.line_len(row),
725                "line_len({row})"
726            );
727        }
728    }
729}