Reapply "Access to imports in the VM's runtime mirrors. Extend test coverage of the source mirrors."

tests/lib/mirrors/library_imports_metadata_test.dart

+// Copyright (c) 2014, 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 test.library_imports;
+
+import 'dart:mirrors';
+import 'package:expect/expect.dart';
+import 'stringify.dart';
+
+import 'library_imports_metadata.dart';
+
+main() {
+  LibraryMirror lib = currentMirrorSystem().findLibrary(#library_imports_metadata);
+
+  LibraryMirror core = currentMirrorSystem().findLibrary(#dart.core);
+  LibraryMirror mirrors = currentMirrorSystem().findLibrary(#dart.mirrors);
+  LibraryMirror collection = currentMirrorSystem().findLibrary(#dart.collection);
+  LibraryMirror async = currentMirrorSystem().findLibrary(#dart.async);
+
+  Expect.setEquals([core, mirrors, collection, async],
+                   lib.libraryDependencies.map((dep) => dep.targetLibrary));
+
+  Expect.stringEquals(
+      'import dart.async\n'
+      'import dart.collection\n'
+      'import dart.core\n'
+      'import dart.mirrors as mirrors\n',
+      stringifyDependencies(lib));
+
+  Expect.listEquals(
+      [].map(reflect).toList(),
+      lib.libraryDependencies
+          .singleWhere((dep) => dep.targetLibrary == core).metadata);
+
+  Expect.listEquals(
+      [m1].map(reflect).toList(),
+      lib.libraryDependencies
+          .singleWhere((dep) => dep.targetLibrary == mirrors).metadata);
+
+  Expect.listEquals(
+      [m2, m3].map(reflect).toList(),
+      lib.libraryDependencies
+          .singleWhere((dep) => dep.targetLibrary == collection).metadata);
+
+  Expect.listEquals(
+      [].map(reflect).toList(),
+      lib.libraryDependencies
+          .singleWhere((dep) => dep.targetLibrary == async).metadata);
+}