conflict_set.rs

  1use gpui::{App, Context, Entity, EventEmitter};
  2use std::{cmp::Ordering, ops::Range, sync::Arc};
  3use text::{Anchor, BufferId, OffsetRangeExt as _};
  4
  5pub struct ConflictSet {
  6    pub has_conflict: bool,
  7    pub snapshot: ConflictSetSnapshot,
  8}
  9
 10#[derive(Clone, Debug, PartialEq, Eq)]
 11pub struct ConflictSetUpdate {
 12    pub buffer_range: Option<Range<Anchor>>,
 13    pub old_range: Range<usize>,
 14    pub new_range: Range<usize>,
 15}
 16
 17#[derive(Debug, Clone)]
 18pub struct ConflictSetSnapshot {
 19    pub buffer_id: BufferId,
 20    pub conflicts: Arc<[ConflictRegion]>,
 21}
 22
 23impl ConflictSetSnapshot {
 24    pub fn conflicts_in_range(
 25        &self,
 26        range: Range<Anchor>,
 27        buffer: &text::BufferSnapshot,
 28    ) -> &[ConflictRegion] {
 29        let start_ix = self
 30            .conflicts
 31            .binary_search_by(|conflict| {
 32                conflict
 33                    .range
 34                    .end
 35                    .cmp(&range.start, buffer)
 36                    .then(Ordering::Greater)
 37            })
 38            .unwrap_err();
 39        let end_ix = start_ix
 40            + self.conflicts[start_ix..]
 41                .binary_search_by(|conflict| {
 42                    conflict
 43                        .range
 44                        .start
 45                        .cmp(&range.end, buffer)
 46                        .then(Ordering::Less)
 47                })
 48                .unwrap_err();
 49        &self.conflicts[start_ix..end_ix]
 50    }
 51
 52    pub fn compare(&self, other: &Self, buffer: &text::BufferSnapshot) -> ConflictSetUpdate {
 53        let common_prefix_len = self
 54            .conflicts
 55            .iter()
 56            .zip(other.conflicts.iter())
 57            .take_while(|(old, new)| old == new)
 58            .count();
 59        let common_suffix_len = self.conflicts[common_prefix_len..]
 60            .iter()
 61            .rev()
 62            .zip(other.conflicts[common_prefix_len..].iter().rev())
 63            .take_while(|(old, new)| old == new)
 64            .count();
 65        let old_conflicts =
 66            &self.conflicts[common_prefix_len..(self.conflicts.len() - common_suffix_len)];
 67        let new_conflicts =
 68            &other.conflicts[common_prefix_len..(other.conflicts.len() - common_suffix_len)];
 69        let old_range = common_prefix_len..(common_prefix_len + old_conflicts.len());
 70        let new_range = common_prefix_len..(common_prefix_len + new_conflicts.len());
 71        let start = match (old_conflicts.first(), new_conflicts.first()) {
 72            (None, None) => None,
 73            (None, Some(conflict)) => Some(conflict.range.start),
 74            (Some(conflict), None) => Some(conflict.range.start),
 75            (Some(first), Some(second)) => {
 76                Some(*first.range.start.min(&second.range.start, buffer))
 77            }
 78        };
 79        let end = match (old_conflicts.last(), new_conflicts.last()) {
 80            (None, None) => None,
 81            (None, Some(conflict)) => Some(conflict.range.end),
 82            (Some(first), None) => Some(first.range.end),
 83            (Some(first), Some(second)) => Some(*first.range.end.max(&second.range.end, buffer)),
 84        };
 85        ConflictSetUpdate {
 86            buffer_range: start.zip(end).map(|(start, end)| start..end),
 87            old_range,
 88            new_range,
 89        }
 90    }
 91}
 92
 93#[derive(Debug, Clone, PartialEq, Eq)]
 94pub struct ConflictRegion {
 95    pub range: Range<Anchor>,
 96    pub ours: Range<Anchor>,
 97    pub theirs: Range<Anchor>,
 98    pub base: Option<Range<Anchor>>,
 99}
100
101impl ConflictRegion {
102    pub fn resolve(
103        &self,
104        buffer: Entity<language::Buffer>,
105        ranges: &[Range<Anchor>],
106        cx: &mut App,
107    ) {
108        let buffer_snapshot = buffer.read(cx).snapshot();
109        let mut deletions = Vec::new();
110        let empty = "";
111        let outer_range = self.range.to_offset(&buffer_snapshot);
112        let mut offset = outer_range.start;
113        for kept_range in ranges {
114            let kept_range = kept_range.to_offset(&buffer_snapshot);
115            if kept_range.start > offset {
116                deletions.push((offset..kept_range.start, empty));
117            }
118            offset = kept_range.end;
119        }
120        if outer_range.end > offset {
121            deletions.push((offset..outer_range.end, empty));
122        }
123
124        buffer.update(cx, |buffer, cx| {
125            buffer.edit(deletions, None, cx);
126        });
127    }
128}
129
130impl ConflictSet {
131    pub fn new(buffer_id: BufferId, has_conflict: bool, _: &mut Context<Self>) -> Self {
132        Self {
133            has_conflict,
134            snapshot: ConflictSetSnapshot {
135                buffer_id,
136                conflicts: Default::default(),
137            },
138        }
139    }
140
141    pub fn set_has_conflict(&mut self, has_conflict: bool, cx: &mut Context<Self>) -> bool {
142        if has_conflict != self.has_conflict {
143            self.has_conflict = has_conflict;
144            if !self.has_conflict {
145                cx.emit(ConflictSetUpdate {
146                    buffer_range: None,
147                    old_range: 0..self.snapshot.conflicts.len(),
148                    new_range: 0..0,
149                });
150                self.snapshot.conflicts = Default::default();
151            }
152            true
153        } else {
154            false
155        }
156    }
157
158    pub fn snapshot(&self) -> ConflictSetSnapshot {
159        self.snapshot.clone()
160    }
161
162    pub fn set_snapshot(
163        &mut self,
164        snapshot: ConflictSetSnapshot,
165        update: ConflictSetUpdate,
166        cx: &mut Context<Self>,
167    ) {
168        self.snapshot = snapshot;
169        cx.emit(update);
170    }
171
172    pub fn parse(buffer: &text::BufferSnapshot) -> ConflictSetSnapshot {
173        let mut conflicts = Vec::new();
174
175        let mut line_pos = 0;
176        let buffer_len = buffer.len();
177        let mut lines = buffer.text_for_range(0..buffer_len).lines();
178
179        let mut conflict_start: Option<usize> = None;
180        let mut ours_start: Option<usize> = None;
181        let mut ours_end: Option<usize> = None;
182        let mut base_start: Option<usize> = None;
183        let mut base_end: Option<usize> = None;
184        let mut theirs_start: Option<usize> = None;
185
186        while let Some(line) = lines.next() {
187            let line_end = line_pos + line.len();
188
189            if line.starts_with("<<<<<<< ") {
190                // If we see a new conflict marker while already parsing one,
191                // abandon the previous one and start a new one
192                conflict_start = Some(line_pos);
193                ours_start = Some(line_end + 1);
194            } else if line.starts_with("||||||| ")
195                && conflict_start.is_some()
196                && ours_start.is_some()
197            {
198                ours_end = Some(line_pos);
199                base_start = Some(line_end + 1);
200            } else if line.starts_with("=======")
201                && conflict_start.is_some()
202                && ours_start.is_some()
203            {
204                // Set ours_end if not already set (would be set if we have base markers)
205                if ours_end.is_none() {
206                    ours_end = Some(line_pos);
207                } else if base_start.is_some() {
208                    base_end = Some(line_pos);
209                }
210                theirs_start = Some(line_end + 1);
211            } else if line.starts_with(">>>>>>> ")
212                && conflict_start.is_some()
213                && ours_start.is_some()
214                && ours_end.is_some()
215                && theirs_start.is_some()
216            {
217                let theirs_end = line_pos;
218                let conflict_end = (line_end + 1).min(buffer_len);
219
220                let range = buffer.anchor_after(conflict_start.unwrap())
221                    ..buffer.anchor_before(conflict_end);
222                let ours = buffer.anchor_after(ours_start.unwrap())
223                    ..buffer.anchor_before(ours_end.unwrap());
224                let theirs =
225                    buffer.anchor_after(theirs_start.unwrap())..buffer.anchor_before(theirs_end);
226
227                let base = base_start
228                    .zip(base_end)
229                    .map(|(start, end)| buffer.anchor_after(start)..buffer.anchor_before(end));
230
231                conflicts.push(ConflictRegion {
232                    range,
233                    ours,
234                    theirs,
235                    base,
236                });
237
238                conflict_start = None;
239                ours_start = None;
240                ours_end = None;
241                base_start = None;
242                base_end = None;
243                theirs_start = None;
244            }
245
246            line_pos = line_end + 1;
247        }
248
249        ConflictSetSnapshot {
250            conflicts: conflicts.into(),
251            buffer_id: buffer.remote_id(),
252        }
253    }
254}
255
256impl EventEmitter<ConflictSetUpdate> for ConflictSet {}
257
258#[cfg(test)]
259mod tests {
260    use std::sync::mpsc;
261
262    use crate::Project;
263
264    use super::*;
265    use fs::FakeFs;
266    use git::{
267        repository::{RepoPath, repo_path},
268        status::{UnmergedStatus, UnmergedStatusCode},
269    };
270    use gpui::{BackgroundExecutor, TestAppContext};
271    use serde_json::json;
272    use text::{Buffer, BufferId, Point, ReplicaId, ToOffset as _};
273    use unindent::Unindent as _;
274    use util::{path, rel_path::rel_path};
275
276    #[test]
277    fn test_parse_conflicts_in_buffer() {
278        // Create a buffer with conflict markers
279        let test_content = r#"
280            This is some text before the conflict.
281            <<<<<<< HEAD
282            This is our version
283            =======
284            This is their version
285            >>>>>>> branch-name
286
287            Another conflict:
288            <<<<<<< HEAD
289            Our second change
290            ||||||| merged common ancestors
291            Original content
292            =======
293            Their second change
294            >>>>>>> branch-name
295        "#
296        .unindent();
297
298        let buffer_id = BufferId::new(1).unwrap();
299        let buffer = Buffer::new(ReplicaId::LOCAL, buffer_id, test_content);
300        let snapshot = buffer.snapshot();
301
302        let conflict_snapshot = ConflictSet::parse(&snapshot);
303        assert_eq!(conflict_snapshot.conflicts.len(), 2);
304
305        let first = &conflict_snapshot.conflicts[0];
306        assert!(first.base.is_none());
307        let our_text = snapshot
308            .text_for_range(first.ours.clone())
309            .collect::<String>();
310        let their_text = snapshot
311            .text_for_range(first.theirs.clone())
312            .collect::<String>();
313        assert_eq!(our_text, "This is our version\n");
314        assert_eq!(their_text, "This is their version\n");
315
316        let second = &conflict_snapshot.conflicts[1];
317        assert!(second.base.is_some());
318        let our_text = snapshot
319            .text_for_range(second.ours.clone())
320            .collect::<String>();
321        let their_text = snapshot
322            .text_for_range(second.theirs.clone())
323            .collect::<String>();
324        let base_text = snapshot
325            .text_for_range(second.base.as_ref().unwrap().clone())
326            .collect::<String>();
327        assert_eq!(our_text, "Our second change\n");
328        assert_eq!(their_text, "Their second change\n");
329        assert_eq!(base_text, "Original content\n");
330
331        // Test conflicts_in_range
332        let range = snapshot.anchor_before(0)..snapshot.anchor_before(snapshot.len());
333        let conflicts_in_range = conflict_snapshot.conflicts_in_range(range, &snapshot);
334        assert_eq!(conflicts_in_range.len(), 2);
335
336        // Test with a range that includes only the first conflict
337        let first_conflict_end = conflict_snapshot.conflicts[0].range.end;
338        let range = snapshot.anchor_before(0)..first_conflict_end;
339        let conflicts_in_range = conflict_snapshot.conflicts_in_range(range, &snapshot);
340        assert_eq!(conflicts_in_range.len(), 1);
341
342        // Test with a range that includes only the second conflict
343        let second_conflict_start = conflict_snapshot.conflicts[1].range.start;
344        let range = second_conflict_start..snapshot.anchor_before(snapshot.len());
345        let conflicts_in_range = conflict_snapshot.conflicts_in_range(range, &snapshot);
346        assert_eq!(conflicts_in_range.len(), 1);
347
348        // Test with a range that doesn't include any conflicts
349        let range = buffer.anchor_after(first_conflict_end.to_next_offset(&buffer))
350            ..buffer.anchor_before(second_conflict_start.to_previous_offset(&buffer));
351        let conflicts_in_range = conflict_snapshot.conflicts_in_range(range, &snapshot);
352        assert_eq!(conflicts_in_range.len(), 0);
353    }
354
355    #[test]
356    fn test_nested_conflict_markers() {
357        // Create a buffer with nested conflict markers
358        let test_content = r#"
359            This is some text before the conflict.
360            <<<<<<< HEAD
361            This is our version
362            <<<<<<< HEAD
363            This is a nested conflict marker
364            =======
365            This is their version in a nested conflict
366            >>>>>>> branch-nested
367            =======
368            This is their version
369            >>>>>>> branch-name
370        "#
371        .unindent();
372
373        let buffer_id = BufferId::new(1).unwrap();
374        let buffer = Buffer::new(ReplicaId::LOCAL, buffer_id, test_content);
375        let snapshot = buffer.snapshot();
376
377        let conflict_snapshot = ConflictSet::parse(&snapshot);
378
379        assert_eq!(conflict_snapshot.conflicts.len(), 1);
380
381        // The conflict should have our version, their version, but no base
382        let conflict = &conflict_snapshot.conflicts[0];
383        assert!(conflict.base.is_none());
384
385        // Check that the nested conflict was detected correctly
386        let our_text = snapshot
387            .text_for_range(conflict.ours.clone())
388            .collect::<String>();
389        assert_eq!(our_text, "This is a nested conflict marker\n");
390        let their_text = snapshot
391            .text_for_range(conflict.theirs.clone())
392            .collect::<String>();
393        assert_eq!(their_text, "This is their version in a nested conflict\n");
394    }
395
396    #[test]
397    fn test_conflict_markers_at_eof() {
398        let test_content = r#"
399            <<<<<<< ours
400            =======
401            This is their version
402            >>>>>>> "#
403            .unindent();
404        let buffer_id = BufferId::new(1).unwrap();
405        let buffer = Buffer::new(ReplicaId::LOCAL, buffer_id, test_content);
406        let snapshot = buffer.snapshot();
407
408        let conflict_snapshot = ConflictSet::parse(&snapshot);
409        assert_eq!(conflict_snapshot.conflicts.len(), 1);
410    }
411
412    #[test]
413    fn test_conflicts_in_range() {
414        // Create a buffer with conflict markers
415        let test_content = r#"
416            one
417            <<<<<<< HEAD1
418            two
419            =======
420            three
421            >>>>>>> branch1
422            four
423            five
424            <<<<<<< HEAD2
425            six
426            =======
427            seven
428            >>>>>>> branch2
429            eight
430            nine
431            <<<<<<< HEAD3
432            ten
433            =======
434            eleven
435            >>>>>>> branch3
436            twelve
437            <<<<<<< HEAD4
438            thirteen
439            =======
440            fourteen
441            >>>>>>> branch4
442            fifteen
443        "#
444        .unindent();
445
446        let buffer_id = BufferId::new(1).unwrap();
447        let buffer = Buffer::new(ReplicaId::LOCAL, buffer_id, test_content.clone());
448        let snapshot = buffer.snapshot();
449
450        let conflict_snapshot = ConflictSet::parse(&snapshot);
451        assert_eq!(conflict_snapshot.conflicts.len(), 4);
452
453        let range = test_content.find("seven").unwrap()..test_content.find("eleven").unwrap();
454        let range = buffer.anchor_before(range.start)..buffer.anchor_after(range.end);
455        assert_eq!(
456            conflict_snapshot.conflicts_in_range(range, &snapshot),
457            &conflict_snapshot.conflicts[1..=2]
458        );
459
460        let range = test_content.find("one").unwrap()..test_content.find("<<<<<<< HEAD2").unwrap();
461        let range = buffer.anchor_before(range.start)..buffer.anchor_after(range.end);
462        assert_eq!(
463            conflict_snapshot.conflicts_in_range(range, &snapshot),
464            &conflict_snapshot.conflicts[0..=1]
465        );
466
467        let range =
468            test_content.find("eight").unwrap() - 1..test_content.find(">>>>>>> branch3").unwrap();
469        let range = buffer.anchor_before(range.start)..buffer.anchor_after(range.end);
470        assert_eq!(
471            conflict_snapshot.conflicts_in_range(range, &snapshot),
472            &conflict_snapshot.conflicts[1..=2]
473        );
474
475        let range = test_content.find("thirteen").unwrap() - 1..test_content.len();
476        let range = buffer.anchor_before(range.start)..buffer.anchor_after(range.end);
477        assert_eq!(
478            conflict_snapshot.conflicts_in_range(range, &snapshot),
479            &conflict_snapshot.conflicts[3..=3]
480        );
481    }
482
483    #[gpui::test]
484    async fn test_conflict_updates(executor: BackgroundExecutor, cx: &mut TestAppContext) {
485        zlog::init_test();
486        cx.update(|cx| {
487            settings::init(cx);
488        });
489        let initial_text = "
490            one
491            two
492            three
493            four
494            five
495        "
496        .unindent();
497        let fs = FakeFs::new(executor);
498        fs.insert_tree(
499            path!("/project"),
500            json!({
501                ".git": {},
502                "a.txt": initial_text,
503            }),
504        )
505        .await;
506        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
507        let (git_store, buffer) = project.update(cx, |project, cx| {
508            (
509                project.git_store().clone(),
510                project.open_local_buffer(path!("/project/a.txt"), cx),
511            )
512        });
513        let buffer = buffer.await.unwrap();
514        let conflict_set = git_store.update(cx, |git_store, cx| {
515            git_store.open_conflict_set(buffer.clone(), cx)
516        });
517        let (events_tx, events_rx) = mpsc::channel::<ConflictSetUpdate>();
518        let _conflict_set_subscription = cx.update(|cx| {
519            cx.subscribe(&conflict_set, move |_, event, _| {
520                events_tx.send(event.clone()).ok();
521            })
522        });
523        let conflicts_snapshot =
524            conflict_set.read_with(cx, |conflict_set, _| conflict_set.snapshot());
525        assert!(conflicts_snapshot.conflicts.is_empty());
526
527        buffer.update(cx, |buffer, cx| {
528            buffer.edit(
529                [
530                    (4..4, "<<<<<<< HEAD\n"),
531                    (14..14, "=======\nTWO\n>>>>>>> branch\n"),
532                ],
533                None,
534                cx,
535            );
536        });
537
538        cx.run_until_parked();
539        events_rx.try_recv().expect_err(
540            "no conflicts should be registered as long as the file's status is unchanged",
541        );
542
543        fs.with_git_state(path!("/project/.git").as_ref(), true, |state| {
544            state.unmerged_paths.insert(
545                repo_path("a.txt"),
546                UnmergedStatus {
547                    first_head: UnmergedStatusCode::Updated,
548                    second_head: UnmergedStatusCode::Updated,
549                },
550            );
551            // Cause the repository to emit MergeHeadsChanged.
552            state.refs.insert("MERGE_HEAD".into(), "123".into())
553        })
554        .unwrap();
555
556        cx.run_until_parked();
557        let update = events_rx
558            .try_recv()
559            .expect("status change should trigger conflict parsing");
560        assert_eq!(update.old_range, 0..0);
561        assert_eq!(update.new_range, 0..1);
562
563        let conflict = conflict_set.read_with(cx, |conflict_set, _| {
564            conflict_set.snapshot().conflicts[0].clone()
565        });
566        cx.update(|cx| {
567            conflict.resolve(buffer.clone(), std::slice::from_ref(&conflict.theirs), cx);
568        });
569
570        cx.run_until_parked();
571        let update = events_rx
572            .try_recv()
573            .expect("conflicts should be removed after resolution");
574        assert_eq!(update.old_range, 0..1);
575        assert_eq!(update.new_range, 0..0);
576    }
577
578    #[gpui::test]
579    async fn test_conflict_updates_without_merge_head(
580        executor: BackgroundExecutor,
581        cx: &mut TestAppContext,
582    ) {
583        zlog::init_test();
584        cx.update(|cx| {
585            settings::init(cx);
586        });
587
588        let initial_text = "
589            zero
590            <<<<<<< HEAD
591            one
592            =======
593            two
594            >>>>>>> Stashed Changes
595            three
596        "
597        .unindent();
598
599        let fs = FakeFs::new(executor);
600        fs.insert_tree(
601            path!("/project"),
602            json!({
603                ".git": {},
604                "a.txt": initial_text,
605            }),
606        )
607        .await;
608
609        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
610        let (git_store, buffer) = project.update(cx, |project, cx| {
611            (
612                project.git_store().clone(),
613                project.open_local_buffer(path!("/project/a.txt"), cx),
614            )
615        });
616
617        cx.run_until_parked();
618        fs.with_git_state(path!("/project/.git").as_ref(), true, |state| {
619            state.unmerged_paths.insert(
620                RepoPath::from_rel_path(rel_path("a.txt")),
621                UnmergedStatus {
622                    first_head: UnmergedStatusCode::Updated,
623                    second_head: UnmergedStatusCode::Updated,
624                },
625            )
626        })
627        .unwrap();
628
629        let buffer = buffer.await.unwrap();
630
631        // Open the conflict set for a file that currently has conflicts.
632        let conflict_set = git_store.update(cx, |git_store, cx| {
633            git_store.open_conflict_set(buffer.clone(), cx)
634        });
635
636        cx.run_until_parked();
637        conflict_set.update(cx, |conflict_set, cx| {
638            let conflict_range = conflict_set.snapshot().conflicts[0]
639                .range
640                .to_point(buffer.read(cx));
641            assert_eq!(conflict_range, Point::new(1, 0)..Point::new(6, 0));
642        });
643
644        // Simulate the conflict being removed by e.g. staging the file.
645        fs.with_git_state(path!("/project/.git").as_ref(), true, |state| {
646            state.unmerged_paths.remove(&repo_path("a.txt"))
647        })
648        .unwrap();
649
650        cx.run_until_parked();
651        conflict_set.update(cx, |conflict_set, _| {
652            assert!(!conflict_set.has_conflict);
653            assert_eq!(conflict_set.snapshot.conflicts.len(), 0);
654        });
655
656        // Simulate the conflict being re-added.
657        fs.with_git_state(path!("/project/.git").as_ref(), true, |state| {
658            state.unmerged_paths.insert(
659                repo_path("a.txt"),
660                UnmergedStatus {
661                    first_head: UnmergedStatusCode::Updated,
662                    second_head: UnmergedStatusCode::Updated,
663                },
664            )
665        })
666        .unwrap();
667
668        cx.run_until_parked();
669        conflict_set.update(cx, |conflict_set, cx| {
670            let conflict_range = conflict_set.snapshot().conflicts[0]
671                .range
672                .to_point(buffer.read(cx));
673            assert_eq!(conflict_range, Point::new(1, 0)..Point::new(6, 0));
674        });
675    }
676}