Add mirrors tests

test/codegen/lib/mirrors/metadata_test.dart

+// Copyright (c) 2013, 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.metadata_test;
+
+import 'dart:mirrors';
+
+const string = 'a metadata string';
+
+const symbol = const Symbol('symbol');
+
+const hest = 'hest';
+
+@symbol @string
+class MyClass {
+  @hest @hest @symbol
+  var x;
+  var y;
+
+  @string @symbol @string
+  myMethod() => 1;
+  myOtherMethod() => 2;
+}
+
+checkMetadata(DeclarationMirror mirror, List expectedMetadata) {
+  List metadata = mirror.metadata.map((m) => m.reflectee).toList();
+  if (metadata == null) {
+    throw 'Null metadata on $mirror';
+  }
+  int expectedLength = expectedMetadata.length;
+  int actualLength = metadata.length;
+  if (expectedLength != actualLength) {
+    throw 'Expected length = $expectedLength, but got length = $actualLength.';
+  }
+  for (int i = 0; i < expectedLength; i++) {
+    if (metadata[i] != expectedMetadata[i]) {
+      throw '${metadata[i]} is not "${expectedMetadata[i]}"'
+          ' in $mirror at index $i';
+    }
+  }
+  print(metadata);
+}
+
+@symbol @string @symbol
+main() {
+  if (MirrorSystem.getName(symbol) != 'symbol') {
+    // This happened in dart2js due to how early library metadata is
+    // computed.
+    throw 'Bad constant: $symbol';
+  }
+
+  MirrorSystem mirrors = currentMirrorSystem();
+  ClassMirror myClassMirror = reflectClass(MyClass);
+  checkMetadata(myClassMirror, [symbol, string]);
+  LibraryMirror lib = mirrors.findLibrary(#test.metadata_test);
+  MethodMirror function = lib.declarations[#main];
+  checkMetadata(function, [symbol, string, symbol]);
+  MethodMirror method = myClassMirror.declarations[#myMethod];
+  checkMetadata(method, [string, symbol, string]);
+  method = myClassMirror.declarations[#myOtherMethod];
+  checkMetadata(method, []);
+
+  VariableMirror xMirror = myClassMirror.declarations[#x];
+  checkMetadata(xMirror, [hest, hest, symbol]);
+
+  VariableMirror yMirror = myClassMirror.declarations[#y];
+  checkMetadata(yMirror, []);
+
+  // TODO(ahe): Test local functions.
+}