Lint to check for declared return types (#146).

test/rules/always_declare_return_types.dart

Index: test/rules/always_declare_return_types.dart
diff --git a/test/rules/always_declare_return_types.dart b/test/rules/always_declare_return_types.dart
new file mode 100644
index 0000000000000000000000000000000000000000..d58c77f0aceee1164e76984f6891715b4ac99a50
--- /dev/null
+++ b/test/rules/always_declare_return_types.dart
@@ -0,0 +1,23 @@
+// 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.
+
+main() { } //LINT
+
+bar() => new _Foo(); //LINT
+
+class _Foo {
+  _foo() => 42; //LINT
+}
+
+typedef bad(int x); //LINT
+
+typedef bool predicate(Object o);
+
+void main2() { }
+
+_Foo bar2() => new _Foo();
+
+class _Foo2 {
+  int _foo() => 42;
+}