Add more tests for native JS types in variable windows (#1373)

* Add more tests for native JS types in variable windows

* Update variable_scope_test.dart

Author: Anna Gringauze

dwds/test/variable_scope_test.dart

@@ -72,6 +72,38 @@ void main() {
       return stack;
     }
 
+    Future<Instance> getInstance(InstanceRef ref) async {
+      var result = await service.getObject(isolateId, ref.id);
+      expect(result, isA<Instance>());
+      return result as Instance;
+    }
+
+    void expectDartObject(String variableName, Instance instance) {
+      expect(
+          instance,
+          isA<Instance>().having(
+              (instance) => instance.classRef.name,
+              '$variableName: classRef.name',
+              isNot(isIn([
+                'NativeJavaScriptObject',
+                'JavaScriptObject',
+              ]))));
+    }
+
+    Future<void> expectDartVariables(Map<String, InstanceRef> variables) async {
+      for (var name in variables.keys) {
+        var instance = await getInstance(variables[name]);
+        expectDartObject(name, instance);
+      }
+    }
+
+    Map<String, InstanceRef> getFrameVariables(Frame frame) {
+      return <String, InstanceRef>{
+        for (var variable in frame.vars)
+          variable.name: variable.value as InstanceRef,
+      };
+    }
+
     setUp(() async {
       vm = await service.getVM();
       isolateId = vm.isolates.first.id;
@@ -88,17 +120,19 @@ void main() {
 
     test('variables in static function', () async {
       stack = await breakAt('staticFunction', mainScript);
-      var frame = stack.frames.first;
-      var variableNames = frame.vars.map((variable) => variable.name).toList()
-        ..sort();
+      var variables = getFrameVariables(stack.frames.first);
+      await expectDartVariables(variables);
+
+      var variableNames = variables.keys.toList()..sort();
       expect(variableNames, containsAll(['formal']));
     });
 
     test('variables in function', () async {
       stack = await breakAt('nestedFunction', mainScript);
-      var frame = stack.frames.first;
-      var variableNames = frame.vars.map((variable) => variable.name).toList()
-        ..sort();
+      var variables = getFrameVariables(stack.frames.first);
+      await expectDartVariables(variables);
+
+      var variableNames = variables.keys.toList()..sort();
       expect(
           variableNames,
           containsAll([
@@ -115,21 +149,35 @@ void main() {
 
     test('variables in closure nested in method', () async {
       stack = await breakAt('nestedClosure', mainScript);
-      var frame = stack.frames.first;
-      var variableNames = frame.vars.map((variable) => variable.name).toList()
-        ..sort();
+      var variables = getFrameVariables(stack.frames.first);
+      await expectDartVariables(variables);
+
+      var variableNames = variables.keys.toList()..sort();
       expect(variableNames,
           ['closureLocalInsideMethod', 'local', 'parameter', 'this']);
     });
 
     test('variables in method', () async {
       stack = await breakAt('printMethod', mainScript);
-      var frame = stack.frames.first;
-      var variableNames = frame.vars.map((variable) => variable.name).toList()
-        ..sort();
+      var variables = getFrameVariables(stack.frames.first);
+      await expectDartVariables(variables);
+
+      var variableNames = variables.keys.toList()..sort();
       expect(variableNames, ['this']);
     });
 
+    test('variables in extension method', () async {
+      stack = await breakAt('extension', mainScript);
+      var variables = getFrameVariables(stack.frames.first);
+      await expectDartVariables(variables);
+
+      var variableNames = variables.keys.toList()..sort();
+      // Note: '$this' should change to 'this', and 'return' should
+      // disappear after debug symbols are available.
+      // https://github.com/dart-lang/webdev/issues/1371
+      expect(variableNames, ['\$this', 'ret', 'return']);
+    });
+
     test('evaluateJsOnCallFrame', () async {
       stack = await breakAt('nestedFunction', mainScript);
       var inspector = service.appInspectorProvider();

example/web/scopes_main.dart

@@ -59,6 +59,8 @@ void main() async {
     localList.add('abc');
     var f = testClass.methodWithVariables();
     print(f('parameter'));
+    var num = '1234'.someExtensionMethod();
+    print('$num');
   });
 
   print(_libraryPrivateFinal);
@@ -154,3 +156,10 @@ class NotReallyAList extends ListBase<Object?> {
   @override
   set length(x) => _internal.length = x;
 }
+
+extension NumberParsing on String {
+  int someExtensionMethod() {
+    var ret = int.parse(this);
+    return ret; // Breakpoint: extension
+  }
+}