Initial support for generating client and server stubs for Dart.

test/client_generator_test.dart

+#!/usr/bin/env dart
+// Copyright (c) 2015, 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.
+
+library client_generator_test;
+
+import 'package:protoc_plugin/src/descriptor.pb.dart';
+import 'package:protoc_plugin/src/plugin.pb.dart';
+import 'package:protoc_plugin/protoc.dart';
+import 'package:unittest/unittest.dart';
+
+ServiceDescriptorProto buildServiceDescriptor() {
+  ServiceDescriptorProto sd = new ServiceDescriptorProto()
+    ..name = 'Test'
+    ..method.addAll([
+      new MethodDescriptorProto()
+        ..name = 'aMethod'
+        ..inputType = 'SomeRequest'
+        ..outputType = 'SomeReply',
+      new MethodDescriptorProto()
+        ..name = 'anotherMethod'
+        ..inputType = '.foo.bar.EmptyMessage'
+        ..outputType = '.foo.bar.AnotherReply',
+    ]);
+  return sd;
+}
+
+void main() {
+  test('testClientGenerator', () {
+    // NOTE: Below > 80 cols because it is matching generated code > 80 cols.
+    String expected = r'''
+class TestApi {
+  ProtobufClient _client;
+  TestApi(this._client);
+
+  Future<SomeReply> aMethod(ClientContext ctx, SomeRequest request) async {
+    var resultBytes = await _client.Invoke(ctx, '/Test.aMethod', request.writeToBuffer());
+    return new SomeReply.fromBuffer(resultBytes);
+  }
+  Future<AnotherReply> anotherMethod(ClientContext ctx, EmptyMessage request) async {
+    var resultBytes = await _client.Invoke(ctx, '/Test.anotherMethod', request.writeToBuffer());
+    return new AnotherReply.fromBuffer(resultBytes);
+  }
+}
+
+''';
+    var options = parseGenerationOptions(
+        new CodeGeneratorRequest(), new CodeGeneratorResponse());
+    var context =
+        new GenerationContext(options, new DefaultOutputConfiguration());
+    var fd = new FileDescriptorProto();
+    var fg = new FileGenerator(fd, null, context);
+    ServiceDescriptorProto sd = buildServiceDescriptor();
+    MemoryWriter buffer = new MemoryWriter();
+    IndentingWriter writer = new IndentingWriter('  ', buffer);
+    ClientApiGenerator cag = new ClientApiGenerator(sd, fg, context);
+    cag.generate(writer);
+    expect(buffer.toString(), expected);
+  });
+}