[analysis_server] Immediately return null for getEditableArgs of non-Dart files

See flutter/devtools#9048

Change-Id: I5edb446cbda6f9a4222f2aca8dfd72ccbf334287
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/416780
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Elliott Brooks <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: DanTup

pkg/analysis_server/lib/src/lsp/handlers/custom/editable_arguments/handler_editable_arguments.dart

@@ -42,6 +42,10 @@ class EditableArgumentsHandler
     MessageInfo message,
     CancellationToken token,
   ) async {
+    if (!isDartDocument(params.textDocument)) {
+      return success(null);
+    }
+
     var textDocument = params.textDocument;
     var position = params.position;
 

pkg/analysis_server/test/shared/shared_editable_arguments_tests.dart

@@ -6,6 +6,7 @@ import 'package:analysis_server/lsp_protocol/protocol.dart';
 import 'package:analyzer/src/test_utilities/test_code_format.dart';
 import 'package:test/test.dart';
 
+import '../../tool/codebase/failing_tests.dart';
 import '../lsp/request_helpers_mixin.dart';
 import '../utils/test_code_extensions.dart';
 import 'shared_test_interface.dart';
@@ -765,6 +766,23 @@ class MyWidget extends StatelessWidget {
     expect(result, isNull);
   }
 
+  Future<void> test_location_bad_nonDart() async {
+    var textFilePath = pathContext.join(projectFolderPath, 'lib', 'test.txt');
+    var textFileUri = Uri.file(textFilePath);
+
+    var content = 'my text';
+    createFile(textFilePath, content);
+    await initializeServer();
+    await openFile(textFileUri, content);
+    await currentAnalysis;
+    var result = await getEditableArguments(
+      textFileUri,
+      Position(line: 0, character: 0),
+    );
+
+    expect(result, isNull);
+  }
+
   Future<void> test_location_bad_unnamedConstructor_notWidget() async {
     var result = await getEditableArgumentsFor('''
 class MyWidget {

pkg/analysis_server/test/shared/shared_test_interface.dart

@@ -24,6 +24,9 @@ abstract interface class SharedTestInterface {
   /// be overridden for tests that are deliberately testing invalid code.
   set failTestOnErrorDiagnostic(bool value);
 
+  /// Gets the full normalized path of the test project folder.
+  String get projectFolderPath;
+
   /// Gets the full normalized file path of a file named "test.dart" in the test
   /// project.
   String get testFilePath;