First pass at asynchronous input loading in dart2js.

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 "package:expect/expect.dart";
 import 'compiler_helper.dart';
 import 'parser_helper.dart';
 
 void checkPosition(Spannable spannable, Node node, String source, compiler) {
   SourceSpan span = compiler.spanFromSpannable(spannable);
   Expect.isTrue(span.begin < span.end,
                 'begin = ${span.begin}; end = ${span.end}');
   Expect.isTrue(span.end < source.length,
                 'end = ${span.end}; length = ${source.length}');
   String yield = source.substring(span.begin, span.end);
 
   // TODO(ahe): The node does not include "@". Fix that.
   Expect.stringEquals('@$node', yield);
 }
 
 void checkAnnotation(String name, String declaration,
                      {bool isTopLevelOnly: false}) {
-  var source;
-
   // Ensure that a compile-time constant can be resolved from an
   // annotation.
-  source = """const native = 'xyz';
-              @native
-              $declaration
-              main() {}""";
+  var source1 = """const native = 'xyz';
+                   @native
+                   $declaration
+                   main() {}""";
 
-  compileAndCheck(source, name, (compiler, element) {
+  compileAndCheck(source1, name, (compiler, element) {
     compiler.enqueuer.resolution.queueIsClosed = false;
     Expect.equals(1, length(element.metadata));
     PartialMetadataAnnotation annotation = element.metadata.head;
     annotation.ensureResolved(compiler);
     Constant value = annotation.value;
     Expect.stringEquals('xyz', value.value.slowToString());
 
-    checkPosition(annotation, annotation.cachedNode, source, compiler);
+    checkPosition(annotation, annotation.cachedNode, source1, compiler);
   });
 
   // Ensure that each repeated annotation has a unique instance of
   // [MetadataAnnotation].
-  source = """const native = 'xyz';
-              @native @native
-              $declaration
-              main() {}""";
+  var source2 = """const native = 'xyz';
+                   @native @native
+                   $declaration
+                   main() {}""";
 
-  compileAndCheck(source, name, (compiler, element) {
+  compileAndCheck(source2, name, (compiler, element) {
     compiler.enqueuer.resolution.queueIsClosed = false;
     Expect.equals(2, length(element.metadata));
     PartialMetadataAnnotation annotation1 = element.metadata.head;
     PartialMetadataAnnotation annotation2 = element.metadata.tail.head;
     annotation1.ensureResolved(compiler);
     annotation2.ensureResolved(compiler);
     Expect.isFalse(identical(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());
 
-    checkPosition(annotation1, annotation1.cachedNode, source, compiler);
-    checkPosition(annotation2, annotation2.cachedNode, source, compiler);
+    checkPosition(annotation1, annotation1.cachedNode, source2, compiler);
+    checkPosition(annotation2, annotation2.cachedNode, source2, compiler);
   });
 
   if (isTopLevelOnly) return;
 
   // Ensure that a compile-time constant can be resolved from an
   // annotation.
-  source = """const native = 'xyz';
-              class Foo {
-                @native
-                $declaration
-              }
-              main() {}""";
+  var source3 = """const native = 'xyz';
+                   class Foo {
+                     @native
+                     $declaration
+                   }
+                   main() {}""";
 
-  compileAndCheck(source, 'Foo', (compiler, element) {
+  compileAndCheck(source3, 'Foo', (compiler, element) {
     compiler.enqueuer.resolution.queueIsClosed = false;
     Expect.equals(0, length(element.metadata));
     element.ensureResolved(compiler);
     Expect.equals(0, length(element.metadata));
     element = element.lookupLocalMember(buildSourceString(name));
     Expect.equals(1, length(element.metadata));
     PartialMetadataAnnotation annotation = element.metadata.head;
     annotation.ensureResolved(compiler);
     Constant value = annotation.value;
     Expect.stringEquals('xyz', value.value.slowToString());
 
-    checkPosition(annotation, annotation.cachedNode, source, compiler);
+    checkPosition(annotation, annotation.cachedNode, source3, compiler);
   });
 
   // Ensure that each repeated annotation has a unique instance of
   // [MetadataAnnotation].
-  source = """const native = 'xyz';
-              class Foo {
-                @native @native
-                $declaration
-              }
-              main() {}""";
+  var source4 = """const native = 'xyz';
+                   class Foo {
+                     @native @native
+                     $declaration
+                   }
+                   main() {}""";
 
-  compileAndCheck(source, 'Foo', (compiler, element) {
+  compileAndCheck(source4, 'Foo', (compiler, element) {
     compiler.enqueuer.resolution.queueIsClosed = false;
     Expect.equals(0, length(element.metadata));
     element.ensureResolved(compiler);
     Expect.equals(0, length(element.metadata));
     element = element.lookupLocalMember(buildSourceString(name));
     Expect.equals(2, length(element.metadata));
     PartialMetadataAnnotation annotation1 = element.metadata.head;
     PartialMetadataAnnotation annotation2 = element.metadata.tail.head;
     annotation1.ensureResolved(compiler);
     annotation2.ensureResolved(compiler);
     Expect.isFalse(identical(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());
 
-    checkPosition(annotation1, annotation1.cachedNode, source, compiler);
-    checkPosition(annotation1, annotation2.cachedNode, source, compiler);
+    checkPosition(annotation1, annotation1.cachedNode, source4, compiler);
+    checkPosition(annotation1, annotation2.cachedNode, source4, compiler);
   });
 }
 
 void testClassMetadata() {
   checkAnnotation('Foo', 'class Foo {}', isTopLevelOnly: true);
 }
 
 void testTopLevelMethodMetadata() {
   checkAnnotation('foo', 'foo() {}');
 }
@@ skipping 12 matching lines @@
     Uri libUri = new Uri(scheme: 'source', path: 'lib.dart');
     String libSource = 'library lib;';
 
     Uri uri = new Uri(scheme: 'source', path: 'main.dart');
 
     Uri async = new Uri(scheme: 'dart', path: 'async');
 
     var compiler = compilerFor(source, uri)
         ..registerSource(partUri, partSource)
         ..registerSource(libUri, libSource)
-        ..registerSource(async, 'class DeferredLibrary {}')
-        ..runCompiler(uri);
-    compiler.enqueuer.resolution.queueIsClosed = false;
-    LibraryElement element = compiler.libraries['$uri'];
-    Expect.isNotNull(element, 'Cannot find $uri');
+        ..registerSource(async, 'class DeferredLibrary {}');
 
-    Link<MetadataAnnotation> metadata = extractMetadata(element);
-    Expect.equals(1, length(metadata));
+    compiler.runCompiler(uri).then((_) {
+      compiler.enqueuer.resolution.queueIsClosed = false;
+      LibraryElement element = compiler.libraries['$uri'];
+      Expect.isNotNull(element, 'Cannot find $uri');
 
-    PartialMetadataAnnotation annotation = metadata.head;
-    annotation.ensureResolved(compiler);
-    Constant value = annotation.value;
-    Expect.stringEquals('xyz', value.value.slowToString());
+      Link<MetadataAnnotation> metadata = extractMetadata(element);
+      Expect.equals(1, length(metadata));
 
-    checkPosition(annotation, annotation.cachedNode, source, compiler);
+      PartialMetadataAnnotation annotation = metadata.head;
+      annotation.ensureResolved(compiler);
+      Constant value = annotation.value;
+      Expect.stringEquals('xyz', value.value.slowToString());
+
+      checkPosition(annotation, annotation.cachedNode, source, compiler);
+    });
   }
 
   var source;
 
   source = """@native
               library foo;
               const native = 'xyz';
               main() {}""";
   compileAndCheckLibrary(source, (e) => e.libraryTag.metadata);
 
@@ skipping 22 matching lines @@
   compileAndCheckLibrary(source,
                          (e) => e.compilationUnits.first.partTag.metadata);
 }
 
 void main() {
   testClassMetadata();
   testTopLevelMethodMetadata();
   testTopLevelFieldMetadata();
   testLibraryTags();
 }