Add action to select inside enclosing brackets (#59005)

## Summary
- add an editor action for selecting the contents of the innermost
enclosing bracket pair
- register the action without assigning a default key binding
- cover cursor, selection, nested bracket, no-op, and multi-cursor cases

## Tests
- cargo fmt --check
- cargo test -p editor test_select_inside_enclosing_bracket --lib
- cargo test -p editor test_move_to_enclosing_bracket --lib

Release Notes:

- Added action to select the contents enclosed by brackets

crates/editor/src/actions.rs

@@ -773,6 +773,8 @@ actions!(
         SelectDown,
         /// Selects the enclosing symbol.
         SelectEnclosingSymbol,
+        /// Selects inside the innermost enclosing bracket pair.
+        SelectInsideEnclosingBracket,
         /// Selects to the start of the next larger syntax node.
         SelectToStartOfLargerSyntaxNode,
         /// Selects to the end of the next larger syntax node.

crates/editor/src/editor_tests.rs

@@ -21266,6 +21266,88 @@ async fn test_move_to_enclosing_bracket(cx: &mut TestAppContext) {
     );
 }
 
+#[gpui::test]
+async fn test_select_inside_enclosing_bracket(cx: &mut TestAppContext) {
+    init_test(cx, |_| {});
+
+    let mut cx = EditorLspTestContext::new_typescript(Default::default(), cx).await;
+
+    #[track_caller]
+    fn assert_after_runs(before: &str, after: &str, runs: usize, cx: &mut EditorLspTestContext) {
+        let _state_context = cx.set_state(before);
+        cx.run_until_parked();
+        for _ in 0..runs {
+            cx.update_editor(|editor, window, cx| {
+                editor.select_inside_enclosing_bracket(&SelectInsideEnclosingBracket, window, cx)
+            });
+        }
+        cx.run_until_parked();
+        cx.assert_editor_state(after);
+    }
+
+    #[track_caller]
+    fn assert(before: &str, after: &str, cx: &mut EditorLspTestContext) {
+        assert_after_runs(before, after, 1, cx);
+    }
+
+    assert("console.log(ˇvar);", "console.log(«varˇ»);", &mut cx);
+    assert("console.logˇ(var);", "console.log(«varˇ»);", &mut cx);
+    assert("console.log(var)ˇ;", "console.log(«varˇ»);", &mut cx);
+    assert(
+        "let numbers = [1, ˇ2, 3];",
+        "let numbers = [«1, 2, 3ˇ»];",
+        &mut cx,
+    );
+    assert(
+        "const object = { foo: ˇbar };",
+        "const object = {« foo: bar ˇ»};",
+        &mut cx,
+    );
+    assert(
+        r#"const doubleQuoted = "foo ˇbar";"#,
+        r#"const doubleQuoted = "«foo barˇ»";"#,
+        &mut cx,
+    );
+    assert(
+        "const singleQuoted = 'foo ˇbar';",
+        "const singleQuoted = '«foo barˇ»';",
+        &mut cx,
+    );
+    assert(
+        "const template = `foo ˇbar`;",
+        "const template = `«foo barˇ»`;",
+        &mut cx,
+    );
+    assert(
+        "let result = foo(bar(ˇbaz));",
+        "let result = foo(bar(«bazˇ»));",
+        &mut cx,
+    );
+    assert(
+        "let result = foo(«barˇ»(baz));",
+        "let result = foo(«bar(baz)ˇ»);",
+        &mut cx,
+    );
+    assert_after_runs(
+        "let result = foo(bar(ˇbaz));",
+        "let result = foo(«bar(baz)ˇ»);",
+        2,
+        &mut cx,
+    );
+    assert_after_runs(
+        r#"let result = (xx[xxx{xxˇx}] xx"xxx"xx);"#,
+        r#"let result = («xx[xxx{xxx}] xx"xxx"xxˇ»);"#,
+        3,
+        &mut cx,
+    );
+    assert("let plain = ˇvalue;", "let plain = ˇvalue;", &mut cx);
+    assert(
+        "foo(ˇone); bar(ˇtwo);",
+        "foo(«oneˇ»); bar(«twoˇ»);",
+        &mut cx,
+    );
+}
+
 #[gpui::test]
 async fn test_move_to_enclosing_bracket_in_markdown_code_block(cx: &mut TestAppContext) {
     init_test(cx, |_| {});

crates/editor/src/element.rs

@@ -334,6 +334,7 @@ impl EditorElement {
         register_action(editor, window, Editor::move_to_start_of_larger_syntax_node);
         register_action(editor, window, Editor::move_to_end_of_larger_syntax_node);
         register_action(editor, window, Editor::select_enclosing_symbol);
+        register_action(editor, window, Editor::select_inside_enclosing_bracket);
         register_action(editor, window, Editor::move_to_enclosing_bracket);
         register_action(editor, window, Editor::undo_selection);
         register_action(editor, window, Editor::redo_selection);

crates/editor/src/selection.rs

@@ -966,6 +966,43 @@ impl Editor {
         self.select_to_syntax_nodes(window, cx, true);
     }
 
+    pub fn select_inside_enclosing_bracket(
+        &mut self,
+        _: &SelectInsideEnclosingBracket,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        self.change_selections(Default::default(), window, cx, |s| {
+            s.move_offsets_with(&mut |snapshot, selection| {
+                let Some(enclosing_bracket_ranges) =
+                    snapshot.enclosing_bracket_ranges(selection.start..selection.end)
+                else {
+                    return;
+                };
+
+                let mut best = None;
+                let mut best_length = usize::MAX;
+
+                for (open, close) in enclosing_bracket_ranges {
+                    let inside = open.end..close.start;
+                    if inside == (selection.start..selection.end) {
+                        continue;
+                    }
+
+                    let length = close.end - open.start;
+                    if length < best_length {
+                        best_length = length;
+                        best = Some(inside);
+                    }
+                }
+
+                if let Some(inside) = best {
+                    selection.set_head_tail(inside.end, inside.start, SelectionGoal::None);
+                }
+            })
+        });
+    }
+
     pub fn move_to_enclosing_bracket(
         &mut self,
         _: &MoveToEnclosingBracket,