Fix pairs of almost-adjacent hunks toggling together

crates/editor/src/element.rs

@@ -558,7 +558,7 @@ impl EditorElement {
         let mut modifiers = event.modifiers;
 
         if let Some(hovered_hunk) = hovered_hunk {
-            editor.toggle_diff_hunks_in_ranges(vec![hovered_hunk], cx);
+            editor.toggle_diff_hunks_in_ranges(vec![hovered_hunk.start..hovered_hunk.start], cx);
             cx.notify();
             return;
         } else if gutter_hitbox.is_hovered(window) {

crates/multi_buffer/src/multi_buffer_tests.rs

@@ -493,6 +493,47 @@ fn test_diff_hunks_in_range(cx: &mut TestAppContext) {
     );
 }
 
+#[gpui::test]
+fn test_toggle_adjacent_hunks(cx: &mut TestAppContext) {
+    let base_text = "b\n";
+    let text = "a\nb\nc\n";
+
+    let buffer = cx.new(|cx| Buffer::local(text, cx));
+    let change_set = cx.new(|cx| BufferChangeSet::new_with_base_text(&base_text, &buffer, cx));
+    let multibuffer = cx.new(|cx| MultiBuffer::singleton(buffer.clone(), cx));
+
+    let (mut snapshot, mut subscription) = multibuffer.update(cx, |multibuffer, cx| {
+        multibuffer.add_change_set(change_set.clone(), cx);
+        (multibuffer.snapshot(cx), multibuffer.subscribe())
+    });
+
+    assert_new_snapshot(
+        &multibuffer,
+        &mut snapshot,
+        &mut subscription,
+        cx,
+        "a\nb\nc\n",
+    );
+
+    multibuffer.update(cx, |multibuffer, cx| {
+        let start = multibuffer
+            .buffer_point_to_anchor(&buffer, Point::new(0, 0), cx)
+            .unwrap();
+        let end = multibuffer
+            .buffer_point_to_anchor(&buffer, Point::new(1, 0), cx)
+            .unwrap();
+        multibuffer.expand_diff_hunks(vec![start..end], cx);
+    });
+
+    assert_new_snapshot(
+        &multibuffer,
+        &mut snapshot,
+        &mut subscription,
+        cx,
+        "+ a\n  b\n  c\n",
+    );
+}
+
 #[gpui::test]
 fn test_editing_text_in_diff_hunks(cx: &mut TestAppContext) {
     let base_text = "one\ntwo\nfour\nfive\nsix\nseven\n";