CLI support for embedders (#25380).

pkg/analyzer_cli/test/embedder_test.dart

+// Copyright (c) 2016, 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:io';
+
+import 'package:analyzer_cli/src/driver.dart' show Driver, errorSink, outSink;
+import 'package:path/path.dart' as path;
+import 'package:unittest/unittest.dart';
+
+import 'utils.dart';
+
+main() {
+  group('_embedder.yaml', () {
+    StringSink savedOutSink, savedErrorSink;
+    int savedExitCode;
+
+    setUp(() {
+      savedOutSink = outSink;
+      savedErrorSink = errorSink;
+      savedExitCode = exitCode;
+      outSink = new StringBuffer();
+      errorSink = new StringBuffer();
+    });
+    tearDown(() {
+      outSink = savedOutSink;
+      errorSink = savedErrorSink;
+      exitCode = savedExitCode;
+    });
+
+    initializeTestEnvironment();

[Brian Wilkerson, 2016/01/26 19:12:33]

Perhaps move outside the group?

[pquitslund, 2016/01/26 19:22:19]

Done.

+
+    test('resolution', wrap(() {
+      var testDir = path.join(testDirectory, 'data', 'embedder_client');
+      new Driver().start([
+        '--packages',
+        path.join(testDir, '_packages'),
+        path.join(testDir, 'embedder_yaml_user.dart')
+      ]);
+
+      expect(exitCode, 0);
+      expect(outSink.toString(), contains('No issues found'));
+    }));
+  });
+}
+
+/// Wrap a function call to dump stdout and stderr in case of an exception.
+Function wrap(Function f) {
+  return () {
+    try {
+      f();
+    } catch (e) {
+      if (outSink.toString().isNotEmpty) {
+        print('stdout:');
+        print(outSink);
+      }
+      if (errorSink.toString().isNotEmpty) {
+        print('stderr:');
+        print(errorSink);
+      }
+      throw e;
+    }
+  };
+}