Extend testing of metadata.

dart/tests/compiler/dart2js/metadata_test.dart

 // Copyright (c) 2012, 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:uri");
 
 #import('compiler_helper.dart');
 
 #import('../../../lib/compiler/implementation/elements/elements.dart');
 #import('../../../lib/compiler/implementation/leg.dart');
 
-void testClassMetadata() {
-  // TODO(ahe): native should be "const", not "final".
-  final source = """final native = 'xyz';
-                    @native class Foo {}
-                    main() {}""";
+void checkTopLevelAnnotation(String name, String declaration) {
+  var source;
 
-  check(compiler, element) {
-    Expect.isFalse(element.metadata.isEmpty());
-    Expect.isTrue(element.metadata.tail.isEmpty());
+  // Ensure that a compile-time constant can be resolved from an
+  // annotation.
+  source = """const native = 'xyz';
+              @native
+              $declaration
+              main() {}""";
+
+  compileAndCheck(source, name, (compiler, element) {
+    Expect.equals(1, length(element.metadata));
     MetadataAnnotation annotation = element.metadata.head;
     annotation.ensureResolved(compiler);
     Constant value = annotation.value;
     Expect.stringEquals('xyz', value.value.slowToString());
-  }
+  });
 
-  compileAndCheck(source, 'Foo', check);
+  // Ensure that each repeated annotation has a unique instance of
+  // [MetadataAnnotation].
+  source = """const native = 'xyz';
+              @native @native
+              $declaration
+              main() {}""";
+
+  compileAndCheck(source, name, (compiler, element) {
+    Expect.equals(2, length(element.metadata));
+    MetadataAnnotation annotation1 = element.metadata.head;
+    MetadataAnnotation annotation2 = element.metadata.tail.head;
+    annotation1.ensureResolved(compiler);
+    annotation2.ensureResolved(compiler);
+    Expect.isTrue(annotation1 !== annotation2, 'expected unique instances');
+    Expect.notEquals(annotation1, annotation2, 'expected unequal instances');
+    Constant value1 = annotation1.value;
+    Constant value2 = annotation2.value;
+    Expect.identical(value1, value2, 'expected same compile-time constant');
+    Expect.stringEquals('xyz', value1.value.slowToString());
+    Expect.stringEquals('xyz', value2.value.slowToString());
+  });
+}
+
+void testClassMetadata() {
+  checkTopLevelAnnotation('Foo', 'class Foo {}');
 }
 
 void testTopLevelMethodMetadata() {
-  // TODO(ahe): native should be "const", not "final".
-  final source = """final native = 'xyz';
-                    @native
-                    main() {}""";
+  checkTopLevelAnnotation('foo', 'foo() {}');
+}
 
-  check(compiler, element) {
-    Expect.isFalse(element.metadata.isEmpty());
-    Expect.isTrue(element.metadata.tail.isEmpty());
-    MetadataAnnotation annotation = element.metadata.head;
-    annotation.ensureResolved(compiler);
-    Constant value = annotation.value;
-    Expect.stringEquals('xyz', value.value.slowToString());
-  }
-
-  compileAndCheck(source, 'main', check);
+void testTopLevelFieldMetadata() {
+  checkTopLevelAnnotation('foo', 'var foo;');
 }
 
 void main() {
   testClassMetadata();
   testTopLevelMethodMetadata();
+  testTopLevelFieldMetadata();
 }