From 71128d2ee6b55824c393f2b2b97f2504a86963c0 Mon Sep 17 00:00:00 2001 From: Antonio Scandurra Date: Tue, 2 Aug 2022 16:52:37 +0200 Subject: [PATCH 1/2] Compute diffs based on characters rather than lines Previously, a change on a given line would cause that whole line to be replaced. In turn, this caused anchors on that line to go to the start of that line because they would lie inside of a deleted region after applying the diff. By switching to a character-wise diff, we perform smaller edits to the buffer which stabilizes anchor positions. --- crates/language/src/buffer.rs | 2 +- crates/language/src/tests.rs | 7 +++++-- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/crates/language/src/buffer.rs b/crates/language/src/buffer.rs index e6b0d48820b0db06de9cf96c4c887dbaff561607..353f3182c0b591cd9abea960ab4c534a05056dfc 100644 --- a/crates/language/src/buffer.rs +++ b/crates/language/src/buffer.rs @@ -1006,7 +1006,7 @@ impl Buffer { let old_text = old_text.to_string(); let line_ending = LineEnding::detect(&new_text); LineEnding::normalize(&mut new_text); - let changes = TextDiff::from_lines(old_text.as_str(), new_text.as_str()) + let changes = TextDiff::from_chars(old_text.as_str(), new_text.as_str()) .iter_all_changes() .map(|c| (c.tag(), c.value().len())) .collect::>(); diff --git a/crates/language/src/tests.rs b/crates/language/src/tests.rs index 937ff069305cabe280d4d5de5949ea5423181054..572f2b0ba88d31a62b26ab6660a4d6e203e94089 100644 --- a/crates/language/src/tests.rs +++ b/crates/language/src/tests.rs @@ -183,20 +183,23 @@ fn test_edit_events(cx: &mut gpui::MutableAppContext) { async fn test_apply_diff(cx: &mut gpui::TestAppContext) { let text = "a\nbb\nccc\ndddd\neeeee\nffffff\n"; let buffer = cx.add_model(|cx| Buffer::new(0, text, cx)); + let anchor = buffer.read_with(cx, |buffer, _| buffer.anchor_before(Point::new(3, 3))); let text = "a\nccc\ndddd\nffffff\n"; let diff = buffer.read_with(cx, |b, cx| b.diff(text.into(), cx)).await; buffer.update(cx, |buffer, cx| { buffer.apply_diff(diff, cx).unwrap(); + assert_eq!(buffer.text(), text); + assert_eq!(anchor.to_point(&buffer), Point::new(2, 3)); }); - cx.read(|cx| assert_eq!(buffer.read(cx).text(), text)); let text = "a\n1\n\nccc\ndd2dd\nffffff\n"; let diff = buffer.read_with(cx, |b, cx| b.diff(text.into(), cx)).await; buffer.update(cx, |buffer, cx| { buffer.apply_diff(diff, cx).unwrap(); + assert_eq!(buffer.text(), text); + assert_eq!(anchor.to_point(&buffer), Point::new(4, 4)); }); - cx.read(|cx| assert_eq!(buffer.read(cx).text(), text)); } #[gpui::test] From fc141001344237fa9d3f5b6fca2e181a1653e3b4 Mon Sep 17 00:00:00 2001 From: Antonio Scandurra Date: Tue, 2 Aug 2022 18:48:17 +0200 Subject: [PATCH 2/2] Fix tests --- crates/project/src/project_tests.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crates/project/src/project_tests.rs b/crates/project/src/project_tests.rs index 4c5e9ef8e1b95994dbe9550b745ef6fb091d79b4..3dc4e9359f7dbb87ae5455a1a4ae5f6911ddcefd 100644 --- a/crates/project/src/project_tests.rs +++ b/crates/project/src/project_tests.rs @@ -2498,7 +2498,7 @@ async fn test_buffer_file_changes_on_disk(cx: &mut gpui::TestAppContext) { .collect::>(); assert_eq!( anchor_positions, - [Point::new(1, 1), Point::new(3, 1), Point::new(4, 0)] + [Point::new(1, 1), Point::new(3, 1), Point::new(3, 5)] ); });