feat: anchor review comments to precise text ranges

src/editor.rs

@@ -15990,6 +15990,82 @@ mod tests {
         );
     }
 
+    #[test]
+    fn precise_review_ranges_capture_graphemes_and_navigate_to_their_start() {
+        for focus in [Focus::Before, Focus::After] {
+            for keys in ["lvl", "llvh", "llvj"] {
+                let directory = Directory::new();
+                let root = directory.0.canonicalize().unwrap();
+                let mut editor = editor();
+                historical_diff(
+                    &mut editor,
+                    &root,
+                    vec!["p界e\u{301}z".into(), "before".into()],
+                    vec!["q界e\u{301}z".into(), "after!".into()],
+                );
+                editor.diff.as_mut().unwrap().focus = focus;
+                editor.bind_diff_buffer();
+                let owner = editor.pane_id();
+                type_text(&mut editor, keys);
+                type_text(&mut editor, ":diff.comment");
+                editor.handle(Input::Enter);
+                let diff = editor.workspace_diff().unwrap();
+                let anchor = &diff.local_review.document.comments[0].anchor;
+                let (start, end) = if keys == "llvj" {
+                    (
+                        TextPosition { row: 0, column: 2 },
+                        TextPosition { row: 1, column: 3 },
+                    )
+                } else {
+                    (
+                        TextPosition { row: 0, column: 1 },
+                        TextPosition { row: 0, column: 3 },
+                    )
+                };
+                assert_eq!(anchor.start, start);
+                assert_eq!(anchor.end, end);
+                assert!(diff.review_anchor_current(anchor));
+                editor.handle(Input::Escape);
+                assert_eq!(editor.pane_id(), owner);
+                assert_eq!(
+                    editor.cursor(),
+                    Cursor {
+                        row: start.row,
+                        column: start.column
+                    }
+                );
+            }
+        }
+        for text in ["last", "one\nlast", "one\n", ""] {
+            let directory = Directory::new();
+            let root = directory.0.canonicalize().unwrap();
+            let mut editor = editor();
+            historical_diff(&mut editor, &root, vec!["before".into()], split_lines(text));
+            editor.diff.as_mut().unwrap().focus = Focus::After;
+            editor.bind_diff_buffer();
+            editor.execute("diff.comment");
+            let anchor = &editor
+                .workspace_diff()
+                .unwrap()
+                .local_review
+                .document
+                .comments[0]
+                .anchor;
+            assert_eq!(anchor.start, TextPosition { row: 0, column: 0 });
+            assert_eq!(
+                anchor.end,
+                if text.contains('\n') {
+                    TextPosition { row: 1, column: 0 }
+                } else {
+                    TextPosition {
+                        row: 0,
+                        column: grapheme_count(text),
+                    }
+                }
+            );
+        }
+    }
+
     #[test]
     fn visual_commands_preserve_directed_ranges_on_cancel_and_plugin_dispatch() {
         for shape in ["vll", "vhh", "Vj"] {
@@ -16059,7 +16135,8 @@ mod tests {
             editor.handle(Input::Enter);
             let diff = editor.workspace_diff().unwrap();
             let anchor = diff.local_review.document.comments[0].anchor.clone();
-            assert_eq!((anchor.start_line, anchor.end_line), (1, 2));
+            assert_eq!(anchor.start, TextPosition { row: 0, column: 0 });
+            assert_eq!(anchor.end, TextPosition { row: 2, column: 0 });
             assert_eq!(
                 anchor.side,
                 if focus == Focus::Before {