Implement diff algorithm for libraries.

dart/tests/try/poi/diff_test.dart

Index: dart/tests/try/poi/diff_test.dart
diff --git a/dart/tests/try/poi/diff_test.dart b/dart/tests/try/poi/diff_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..ae384cf80a4e3dfb1cc04662436821fc3a684212
--- /dev/null
+++ b/dart/tests/try/poi/diff_test.dart
@@ -0,0 +1,123 @@
+// 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.
+
+/// Test of element diff.
+library trydart.diff_test;
+
+import 'dart:async' show
+    Future;
+
+import 'package:expect/expect.dart' show
+    Expect;
+
+import 'package:async_helper/async_helper.dart' show
+    asyncTest;
+
+import 'package:compiler/implementation/dart2jslib.dart' show
+    Compiler,
+    Script;
+
+import 'package:compiler/implementation/source_file.dart' show
+    StringSourceFile;
+
+import 'package:compiler/implementation/elements/elements.dart' show
+    Element,
+    LibraryElement;
+
+import 'package:try/poi/diff.dart' show
+    Difference,
+    computeDifference;
+
+import '../../compiler/dart2js/compiler_helper.dart' show
+    MockCompiler,
+    compilerFor;
+
+final TEST_DATA = [
+    {
+      'beforeSource': 'main() {}',
+      'afterSource': 'main() { var x; }',
+      'expectations': [['main', 'main']],
+    },
+    {
+      'beforeSource': 'main() {}',
+      'afterSource': 'main() { /* ignored */ }',
+      'expectations': [],
+    },
+    {
+      'beforeSource': 'main() {}',
+      'afterSource': 'main() { }',
+      'expectations': [],
+    },
+    {
+      'beforeSource': 'var i; main() {}',
+      'afterSource': 'main() { } var i;',
+      'expectations': [],
+    },
+    {
+      'beforeSource': 'main() {}',
+      'afterSource': '',
+      'expectations': [['main', null]],
+    },
+    {
+      'beforeSource': '',
+      'afterSource': 'main() {}',
+      'expectations': [[null, 'main']],
+    },
+];
+
+const String SCHEME = 'org.trydart.diff-test';
+
+Uri customUri(String path) => Uri.parse('$SCHEME://$path');
+
+Future<List<Difference>> testDifference(
+    String beforeSource,
+    String afterSource) {
+  Uri scriptUri = customUri('main.dart');
+  MockCompiler compiler = compilerFor(beforeSource, scriptUri);
+
+  Future<LibraryElement> future = compiler.libraryLoader.loadLibrary(scriptUri);
+  return future.then((LibraryElement library) {
+    Script sourceScript = new Script(
+        scriptUri, scriptUri, new StringSourceFile('$scriptUri', afterSource));
+    var dartPrivacyIsBroken = compiler.libraryLoader;
+    LibraryElement newLibrary = dartPrivacyIsBroken.createLibrarySync(
+        null, sourceScript, scriptUri);
+    return computeDifference(library, newLibrary);
+  });
+}
+
+Future testData(Map data) {
+  String beforeSource = data['beforeSource'];
+  String afterSource = data['afterSource'];
+  List expectations = data['expectations'];
+
+  validate(List<Difference> differences) {
+    return checkExpectations(expectations, differences);
+  }
+
+  return testDifference(beforeSource, afterSource).then(validate);
+}
+
+String elementNameOrNull(Element element) {
+  return element == null ? null : element.name;
+}
+
+checkExpectations(List expectations, List<Difference> differences) {
+  Iterator iterator = expectations.iterator;
+  for (Difference difference in differences) {
+    Expect.isTrue(iterator.moveNext());
+    List expectation = iterator.current;
+    String expectedBeforeName = expectation[0];
+    String expectedAfterName = expectation[1];
+    Expect.stringEquals(
+        expectedBeforeName, elementNameOrNull(difference.before));
+    Expect.stringEquals(expectedAfterName, elementNameOrNull(difference.after));
+    print(difference);
+  }
+  Expect.isFalse(iterator.moveNext());
+}
+
+void main() {
+  asyncTest(() => Future.forEach(TEST_DATA, testData));
+}