Add copyright headers (#1731)
diff --git a/pkgs/checks/lib/checks.dart b/pkgs/checks/lib/checks.dart
index 7124bd3..7ccbe9d 100644
--- a/pkgs/checks/lib/checks.dart
+++ b/pkgs/checks/lib/checks.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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.
+
export 'src/checks.dart' show checkThat, Check;
export 'src/extensions/async.dart' show ChainAsync, FutureChecks, StreamChecks;
export 'src/extensions/core.dart'
diff --git a/pkgs/checks/lib/context.dart b/pkgs/checks/lib/context.dart
index bfd274c..2275395 100644
--- a/pkgs/checks/lib/context.dart
+++ b/pkgs/checks/lib/context.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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.
+
export 'src/checks.dart'
show
Check,
diff --git a/pkgs/checks/lib/src/checks.dart b/pkgs/checks/lib/src/checks.dart
index edc3d5a..e5896b9 100644
--- a/pkgs/checks/lib/src/checks.dart
+++ b/pkgs/checks/lib/src/checks.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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.
+
// TODO Add doc about how failure strings work.
import 'dart:async';
diff --git a/pkgs/checks/lib/src/describe.dart b/pkgs/checks/lib/src/describe.dart
index f604b89..55f5403 100644
--- a/pkgs/checks/lib/src/describe.dart
+++ b/pkgs/checks/lib/src/describe.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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.
+
String literal(Object? o) {
if (o == null || o is num || o is bool) return '<$o>';
// TODO Truncate long strings?
diff --git a/pkgs/checks/lib/src/extensions/async.dart b/pkgs/checks/lib/src/extensions/async.dart
index 6e2f4dd..9ab43dd 100644
--- a/pkgs/checks/lib/src/extensions/async.dart
+++ b/pkgs/checks/lib/src/extensions/async.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:async/async.dart';
diff --git a/pkgs/checks/lib/src/extensions/core.dart b/pkgs/checks/lib/src/extensions/core.dart
index 446bea2..39d2e83 100644
--- a/pkgs/checks/lib/src/extensions/core.dart
+++ b/pkgs/checks/lib/src/extensions/core.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:checks/context.dart';
extension TypeChecks on Check<Object?> {
diff --git a/pkgs/checks/lib/src/extensions/function.dart b/pkgs/checks/lib/src/extensions/function.dart
index aae6f93..9bb4554 100644
--- a/pkgs/checks/lib/src/extensions/function.dart
+++ b/pkgs/checks/lib/src/extensions/function.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:checks/context.dart';
extension ThrowsCheck<T> on Check<T Function()> {
diff --git a/pkgs/checks/lib/src/extensions/iterable.dart b/pkgs/checks/lib/src/extensions/iterable.dart
index 2992192..634ca5f 100644
--- a/pkgs/checks/lib/src/extensions/iterable.dart
+++ b/pkgs/checks/lib/src/extensions/iterable.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:checks/context.dart';
import 'core.dart' show HasField;
diff --git a/pkgs/checks/lib/src/extensions/map.dart b/pkgs/checks/lib/src/extensions/map.dart
index 7ad0c14..e13cf84 100644
--- a/pkgs/checks/lib/src/extensions/map.dart
+++ b/pkgs/checks/lib/src/extensions/map.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:checks/context.dart';
import 'core.dart' show HasField;
diff --git a/pkgs/checks/lib/src/extensions/math.dart b/pkgs/checks/lib/src/extensions/math.dart
index 34ca934..0c25199 100644
--- a/pkgs/checks/lib/src/extensions/math.dart
+++ b/pkgs/checks/lib/src/extensions/math.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:checks/context.dart';
extension NumChecks on Check<num> {
diff --git a/pkgs/checks/test/extensions/core_test.dart b/pkgs/checks/test/extensions/core_test.dart
index 432419e..ac5222e 100644
--- a/pkgs/checks/test/extensions/core_test.dart
+++ b/pkgs/checks/test/extensions/core_test.dart
@@ -1,3 +1,7 @@
+// Copyright (c) 2022, 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:checks/checks.dart';
import 'package:checks/context.dart';
import 'package:test/scaffolding.dart';
