editor: Add comment_on_empty_lines setting for multi-line comment toggle

assets/settings/default.json

@@ -359,6 +359,11 @@
   //
   // Default: 100
   "minimum_split_diff_width": 100,
+  // Whether to insert comment markers on empty lines when toggling comments
+  // in a multi-line selection.
+  //
+  // Default: false
+  "comment_on_empty_lines": false,
   // Show method signatures in the editor, when inside parentheses.
   "auto_signature_help": false,
   // Whether to show the signature help after completion or a bracket pair inserted.

crates/editor/src/actions.rs

@@ -898,6 +898,8 @@ actions!(
         ToggleEditPrediction,
         /// Toggles line numbers display.
         ToggleLineNumbers,
+        /// Toggles comment on empty lines when toggling comments in a multi-line selection.
+        ToggleCommentOnEmptyLines,
         /// Toggles the minimap display.
         ToggleMinimap,
         /// Swaps the start and end of the current selection.

crates/editor/src/config.rs

@@ -82,6 +82,17 @@ impl Editor {
         EditorSettings::override_global(editor_settings, cx);
     }
 
+    pub fn toggle_comment_on_empty_lines(
+        &mut self,
+        _: &ToggleCommentOnEmptyLines,
+        _: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        let mut editor_settings = EditorSettings::get_global(cx).clone();
+        editor_settings.comment_on_empty_lines = !editor_settings.comment_on_empty_lines;
+        EditorSettings::override_global(editor_settings, cx);
+    }
+
     pub fn line_numbers_enabled(&self, cx: &App) -> bool {
         if let Some(show_line_numbers) = self.show_line_numbers {
             return show_line_numbers;

crates/editor/src/editor_settings.rs

@@ -68,6 +68,7 @@ pub struct EditorSettings {
     pub completion_menu_item_kind: CompletionMenuItemKind,
     pub diff_view_style: DiffViewStyle,
     pub minimum_split_diff_width: f32,
+    pub comment_on_empty_lines: bool,
 }
 #[derive(Debug, Clone)]
 pub struct Jupyter {
@@ -311,6 +312,7 @@ impl Settings for EditorSettings {
             completion_menu_item_kind: editor.completion_menu_item_kind.unwrap(),
             diff_view_style: editor.diff_view_style.unwrap(),
             minimum_split_diff_width: editor.minimum_split_diff_width.unwrap(),
+            comment_on_empty_lines: editor.comment_on_empty_lines.unwrap_or(false),
         }
     }
 }

crates/editor/src/editor_tests.rs

@@ -21193,6 +21193,59 @@ async fn test_toggle_comment_ignore_indent(cx: &mut TestAppContext) {
     "});
 }
 
+#[gpui::test]
+async fn test_toggle_comment_with_blank_lines_when_comment_on_empty_lines(
+    cx: &mut TestAppContext,
+) {
+    init_test(cx, |_| {});
+    let mut cx = EditorTestContext::new(cx).await;
+    let language = Arc::new(Language::new(
+        LanguageConfig {
+            line_comments: vec!["// ".into()],
+            ..Default::default()
+        },
+        Some(tree_sitter_rust::LANGUAGE.into()),
+    ));
+    cx.update_buffer(|buffer, cx| buffer.set_language(Some(language), cx));
+
+    cx.update(|_window, cx| {
+        let mut editor_settings = EditorSettings::get_global(cx).clone();
+        editor_settings.comment_on_empty_lines = true;
+        EditorSettings::override_global(editor_settings, cx);
+    });
+
+    // Toggle comment on a multi-line selection with blank lines
+    cx.set_state(indoc! {"
+        fn a() {
+            «a();
+
+            c();ˇ»
+        }
+    "});
+
+    cx.update_editor(|e, window, cx| e.toggle_comments(&ToggleComments::default(), window, cx));
+
+    cx.assert_editor_state(indoc! {"
+        fn a() {
+            // «a();
+            //
+            // c();ˇ»
+        }
+    "});
+
+    // Uncomment: blank line should remain blank (trailing whitespace from padding is OK)
+    cx.update_editor(|e, window, cx| e.toggle_comments(&ToggleComments::default(), window, cx));
+
+    let editor = cx.editor.clone();
+    let text = cx.update(|_window, cx| {
+        editor.update(cx, |editor, cx| {
+            editor.buffer.read(cx).read(cx).text()
+        })
+    });
+    assert!(text.contains("    a();"));
+    assert!(text.contains("    c();"));
+}
+
 #[gpui::test]
 async fn test_advance_downward_on_toggle_comment(cx: &mut TestAppContext) {
     init_test(cx, |_| {});

crates/editor/src/element.rs

@@ -464,6 +464,7 @@ impl EditorElement {
         register_action(editor, window, Editor::toggle_breadcrumb);
         register_action(editor, window, Editor::toggle_line_numbers);
         register_action(editor, window, Editor::toggle_relative_line_numbers);
+        register_action(editor, window, Editor::toggle_comment_on_empty_lines);
         register_action(editor, window, Editor::toggle_indent_guides);
         register_action(editor, window, Editor::toggle_inlay_hints);
         register_action(editor, window, Editor::toggle_inline_values);

crates/editor/src/input.rs

@@ -1545,11 +1545,22 @@ impl Editor {
                         .map(|p| p.trim_end_matches(' ').len())
                         .collect::<SmallVec<[usize; 4]>>();
 
+                    let comment_on_empty_lines =
+                        EditorSettings::get_global(cx).comment_on_empty_lines;
+
                     let mut all_selection_lines_are_comments = true;
+                    let mut blank_prefix_ranges = Vec::new();
 
                     for row in start_row.0..=end_row.0 {
                         let row = MultiBufferRow(row);
-                        if start_row < end_row && snapshot.is_line_blank(row) {
+                        let is_blank_multiline = comment_on_empty_lines
+                            && start_row < end_row
+                            && snapshot.is_line_blank(row);
+
+                        if !comment_on_empty_lines
+                            && start_row < end_row
+                            && snapshot.is_line_blank(row)
+                        {
                             continue;
                         }
 
@@ -1568,11 +1579,14 @@ impl Editor {
                             .max_by_key(|range| range.end.column - range.start.column)
                             .expect("prefixes is non-empty");
 
-                        if prefix_range.is_empty() {
-                            all_selection_lines_are_comments = false;
+                        if is_blank_multiline {
+                            blank_prefix_ranges.push((row, prefix_range));
+                        } else {
+                            if prefix_range.is_empty() {
+                                all_selection_lines_are_comments = false;
+                            }
+                            selection_edit_ranges.push(prefix_range);
                         }
-
-                        selection_edit_ranges.push(prefix_range);
                     }
 
                     if all_selection_lines_are_comments {
@@ -1582,6 +1596,11 @@ impl Editor {
                                 .cloned()
                                 .map(|range| (range, empty_str.clone())),
                         );
+                        for (_, range) in &blank_prefix_ranges {
+                            if !range.is_empty() {
+                                edits.push((range.clone(), empty_str.clone()));
+                            }
+                        }
                     } else {
                         let min_column = selection_edit_ranges
                             .iter()
@@ -1592,6 +1611,22 @@ impl Editor {
                             let position = Point::new(range.start.row, min_column);
                             (position..position, first_prefix.clone())
                         }));
+                        let trimmed_prefix = first_prefix.trim_end();
+                        for (row, range) in &blank_prefix_ranges {
+                            if range.is_empty() {
+                                let len = snapshot.line_len(*row);
+                                let (col, text) = if len >= min_column {
+                                    (min_column, Arc::from(trimmed_prefix))
+                                } else {
+                                    let padding = (min_column - len) as usize;
+                                    let mut s = String::with_capacity(padding + trimmed_prefix.len());
+                                    s.extend(std::iter::repeat(' ').take(padding));
+                                    s.push_str(trimmed_prefix);
+                                    (len, s.into())
+                                };
+                                edits.push((Point::new(row.0, col)..Point::new(row.0, col), text));
+                            }
+                        }
                     }
                 } else if let Some(BlockCommentConfig {
                     start: full_comment_prefix,

crates/settings/src/vscode_import.rs

@@ -319,6 +319,7 @@ impl VsCodeSettings {
             completion_menu_item_kind: None,
             diff_view_style: None,
             minimum_split_diff_width: None,
+            comment_on_empty_lines: None,
         }
     }
 

crates/settings_content/src/editor.rs

@@ -271,6 +271,12 @@ pub struct EditorSettingsContent {
     ///
     /// Default: 100
     pub minimum_split_diff_width: Option<f32>,
+
+    /// Whether to insert comment markers on empty lines when toggling comments
+    /// in a multi-line selection.
+    ///
+    /// Default: false
+    pub comment_on_empty_lines: Option<bool>,
 }
 
 #[derive(