Test to validate copyright headers.

lib/src/rules/avoid_relative_lib_imports.dart

@@ -1,4 +1,4 @@
-// Copyright (c)  2018, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2018, 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.
 

lib/src/util/condition_scope_visitor.dart

@@ -1,3 +1,7 @@
+// Copyright (c) 2018, 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:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';

test/all.dart

@@ -10,6 +10,7 @@ import 'integration_test.dart' as integration_test;
 import 'mocks.dart';
 import 'rule_test.dart' as rule_test;
 import 'utils_test.dart' as utils_test;
+import 'validate_headers_test.dart' as validate_headers;
 
 main() {
   // Redirect output.
@@ -20,4 +21,5 @@ main() {
   integration_test.main();
   rule_test.main();
   utils_test.main();
+  validate_headers.main();
 }

test/validate_headers_test.dart

@@ -0,0 +1,38 @@
+// Copyright (c) 2018, 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 'dart:io';
+
+import 'package:test/test.dart';
+
+main() {
+  group('check for copyright headers', () {
+    test('... in lib', () async {
+      await validate('lib');
+    });
+    test('... in tool', () async {
+      await validate('tool');
+    });
+  });
+}
+
+Future validate(String dir) async {
+  List<String> violations = <String>[];
+  await for (FileSystemEntity entity
+      in new Directory(dir).list(recursive: true, followLinks: false)) {
+    if (entity is File && entity.path.endsWith('.dart')) {
+      RandomAccessFile file = await entity.open();
+      List<int> bytes = await file.read(40);
+      String header = new String.fromCharCodes(bytes);
+      if (!header.startsWith(
+          new RegExp('// Copyright \\(c\\) 20[0-9][0-9], the Dart project'))) {
+        violations.add(entity.path);
+      }
+    }
+  }
+  expect(violations, isEmpty, reason: '''Files missing copyright headers.
+
+See CONTRIBUTING.md for format details.''');
+}