add prompt for using flutter driver to write a test for a user journey (#243)

For clients that have prompts support, this prompt allows a user to provide a user journey and it will instruct the LLM to:

- Try to accomplish the user journey in the live app using flutter driver
- If successful, write a flutter driver test with the same instructions used to accomplish the journey.

TODO: Add support for running flutter driver tests in the MCP server and add that to the prompt.

Author: jakemac53

pkgs/dart_mcp/CHANGELOG.md

@@ -7,7 +7,7 @@
   - This package still allows `reject` and treats it as an alias for`decline`.
   - The old `reject` enum value was replaced with a static constant equal
     exactly to `decline`, so switches are not affected.
-
+- Add `title` parameter to `Prompt` constructor.
 
 ## 0.3.2
 

pkgs/dart_mcp/lib/src/api/api.dart

@@ -503,15 +503,6 @@ extension type ResourceLink.fromMap(Map<String, Object?> _value)
     return type;
   }
 
-  /// The name of the resource.
-  String get name {
-    final name = _value['name'] as String?;
-    if (name == null) {
-      throw ArgumentError('Missing name field in $ResourceLink.');
-    }
-    return name;
-  }
-
   /// The description of the resource.
   String get description {
     final description = _value['description'] as String?;

pkgs/dart_mcp/lib/src/api/prompts.dart

@@ -90,10 +90,12 @@ extension type Prompt.fromMap(Map<String, Object?> _value)
     implements BaseMetadata {
   factory Prompt({
     required String name,
+    String? title,
     String? description,
     List<PromptArgument>? arguments,
   }) => Prompt.fromMap({
     'name': name,
+    if (title != null) 'title': title,
     if (description != null) 'description': description,
     if (arguments != null) 'arguments': arguments,
   });

pkgs/dart_mcp_server/lib/src/mixins/prompts.dart

@@ -0,0 +1,60 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:async';
+
+import 'package:dart_mcp/server.dart';
+import 'package:meta/meta.dart';
+
+/// A mixin which adds support for various dart and flutter specific prompts.
+base mixin DashPrompts on PromptsSupport {
+  @override
+  FutureOr<InitializeResult> initialize(InitializeRequest request) {
+    addPrompt(flutterDriverUserJourneyTest, _flutterDriverUserJourneyPrompt);
+    return super.initialize(request);
+  }
+
+  /// Creates the flutter driver user journey prompt based on a request.
+  GetPromptResult _flutterDriverUserJourneyPrompt(GetPromptRequest request) {
+    return GetPromptResult(
+      messages: [
+        PromptMessage(
+          role: Role.user,
+          content: flutterDriverUserJourneyPromptContent,
+        ),
+      ],
+    );
+  }
+
+  @visibleForTesting
+  static final flutterDriverUserJourneyTest = Prompt(
+    name: 'flutter_driver_user_journey_test',
+    title: 'User journey flutter driver test',
+    description: '''
+Prompts the LLM to attempt to accomplish a user journey in the running app using
+flutter driver. If successful, it will then translate the steps it followed into
+a flutter driver test and write that to disk.
+''',
+  );
+
+  @visibleForTesting
+  static final flutterDriverUserJourneyPromptContent = Content.text(
+    text: '''
+Perform the following tasks in order:
+
+- Prompt the user to navigate to the home page of the app.
+- Prompt the user for a user journey that they would like to write a test for.
+- Attempt to complete the given user journey using flutter driver to inspect the
+  widget tree and interact with the application. Only durable interactions
+  should be performed, do not use temporary IDs to select or interact with
+  widgets, but instead select them based on text, type, tooltip, etc. Avoid
+  reading in files to accomplish this task, just inspect the live state of the
+  app and widget tree. If you get stuck, feel free to ask the user for help.
+- If you are able to successfully complete the journey, then create a flutter
+  driver based test with an appropriate name, which performs all the same
+  actions that you performed. Include the original user journey as a comment
+  in the test file.
+''',
+  );
+}

pkgs/dart_mcp_server/lib/src/server.dart

@@ -19,6 +19,7 @@ import 'arg_parser.dart';
 import 'mixins/analyzer.dart';
 import 'mixins/dash_cli.dart';
 import 'mixins/dtd.dart';
+import 'mixins/prompts.dart';
 import 'mixins/pub.dart';
 import 'mixins/pub_dev_search.dart';
 import 'mixins/roots_fallback_support.dart';
@@ -39,7 +40,9 @@ final class DartMCPServer extends MCPServer
         DashCliSupport,
         PubSupport,
         PubDevSupport,
-        DartToolingDaemonSupport
+        DartToolingDaemonSupport,
+        PromptsSupport,
+        DashPrompts
     implements
         AnalyticsSupport,
         ProcessManagerSupport,

pkgs/dart_mcp_server/pubspec.yaml

@@ -13,7 +13,7 @@ dependencies:
   args: ^2.7.0
   async: ^2.13.0
   collection: ^1.19.1
-  dart_mcp: ^0.3.2
+  dart_mcp: ^0.3.3
   dds_service_extensions: ^2.0.1
   devtools_shared: ^12.0.0
   dtd: ^4.0.0

pkgs/dart_mcp_server/test/tools/prompts_test.dart

@@ -0,0 +1,51 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:dart_mcp/server.dart';
+import 'package:dart_mcp_server/src/mixins/prompts.dart';
+import 'package:test/test.dart';
+
+import '../test_harness.dart';
+
+void main() {
+  late TestHarness testHarness;
+
+  // TODO: Use setUpAll, currently this fails due to an apparent TestProcess
+  // issue.
+  setUp(() async {
+    testHarness = await TestHarness.start();
+  });
+
+  test('can list prompts', () async {
+    final server = testHarness.mcpServerConnection;
+    final promptsResult = await server.listPrompts(ListPromptsRequest());
+    expect(
+      promptsResult.prompts,
+      equals([
+        isA<GetPromptRequest>().having(
+          (p) => p.name,
+          'name',
+          DashPrompts.flutterDriverUserJourneyTest.name,
+        ),
+      ]),
+    );
+  });
+
+  test('can get the flutter driver user journey prompt', () async {
+    final server = testHarness.mcpServerConnection;
+    final prompt = await server.getPrompt(
+      GetPromptRequest(name: DashPrompts.flutterDriverUserJourneyTest.name),
+    );
+    expect(
+      prompt.messages.single,
+      isA<PromptMessage>()
+          .having((m) => m.role, 'role', Role.user)
+          .having(
+            (m) => m.content,
+            'content',
+            equals(DashPrompts.flutterDriverUserJourneyPromptContent),
+          ),
+    );
+  });
+}