Make observable transform a barback transform.

pkg/observe/test/transform_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.
+
+import 'dart:async';
+import 'package:barback/barback.dart';
+import 'package:observe/transform.dart';
+import 'package:unittest/compact_vm_config.dart';
+import 'package:unittest/unittest.dart';
+
+main() {
+  useCompactVMConfiguration();
+
+  group('replaces Observable for ChangeNotifier', () {
+    _testClause('extends ObservableBase', 'extends ChangeNotifierBase');
+    _testClause('extends Base with ObservableMixin',
+        'extends Base with ChangeNotifierMixin');
+    _testClause('extends Base<T> with ObservableMixin',
+        'extends Base<T> with ChangeNotifierMixin');
+    _testClause('extends Base with Mixin, ObservableMixin',
+        'extends Base with Mixin, ChangeNotifierMixin');
+    _testClause('extends Base with ObservableMixin, Mixin',
+        'extends Base with ChangeNotifierMixin, Mixin');
+    _testClause('extends Base with Mixin<T>, ObservableMixin',
+        'extends Base with Mixin<T>, ChangeNotifierMixin');
+    _testClause('extends Base with Mixin, ObservableMixin, Mixin2',
+        'extends Base with Mixin, ChangeNotifierMixin, Mixin2');
+    _testClause('extends ObservableBase implements Interface',
+        'extends ChangeNotifierBase implements Interface');
+    _testClause('extends ObservableBase implements Interface<T>',
+        'extends ChangeNotifierBase implements Interface<T>');
+    _testClause('extends Base with ObservableMixin implements Interface',
+        'extends Base with ChangeNotifierMixin implements Interface');
+    _testClause(
+        'extends Base with Mixin, ObservableMixin implements I1, I2',
+        'extends Base with Mixin, ChangeNotifierMixin implements I1, I2');
+  });
+
+  group('fixes contructor calls ', () {
+    _testInitializers('this.a', '(a) : __\$a = a');
+    _testInitializers('{this.a}', '({a}) : __\$a = a');
+    _testInitializers('[this.a]', '([a]) : __\$a = a');
+    _testInitializers('this.a, this.b', '(a, b) : __\$a = a, __\$b = b');
+    _testInitializers('{this.a, this.b}', '({a, b}) : __\$a = a, __\$b = b');
+    _testInitializers('[this.a, this.b]', '([a, b]) : __\$a = a, __\$b = b');
+    _testInitializers('this.a, [this.b]', '(a, [b]) : __\$a = a, __\$b = b');
+    _testInitializers('this.a, {this.b}', '(a, {b}) : __\$a = a, __\$b = b');
+  });
+}
+
+_testClause(String clauses, String expected) {
+  test(clauses, () {
+    var className = 'MyClass';
+    if (clauses.contains('<T>')) className += '<T>';
+    var code = '''
+      class $className $clauses {
+        @observable var field;
+      }''';
+
+    return _transform(code).then((output) {
+      var classPos = output.indexOf(className) + className.length;
+      var actualClauses = output.substring(classPos,
+        output.indexOf('{')).trim().replaceAll('  ', ' ');
+      expect(actualClauses, expected);
+    });
+  });
+}
+
+_testInitializers(String args, String expected) {
+  test(args, () {
+    var constructor = 'MyClass(';
+    var code = '''
+        class MyClass {
+          @observable var a;
+          @observable var b;
+          MyClass($args);
+        }''';
+
+    return _transform(code).then((output) {
+      var begin = output.indexOf(constructor) + constructor.length - 1;
+      var end = output.indexOf(';', begin);
+      if (end == -1) end = output.length;
+      var init = output.substring(begin, end).trim().replaceAll('  ', ' ');
+      expect(init, expected);
+    });
+  });
+}
+
+/** Helper that applies the transform by creating mock assets. */
+Future<String> _transform(String code) {
+  var id = new AssetId('foo', 'a/b/c.dart');
+  var asset = new Asset.fromString(id, code);
+  var transformer = new ObservableTransformer();
+  return transformer.isPrimary(asset).then((isPrimary) {
+    expect(isPrimary, isTrue);
+    var transform = new _MockTransform(asset);
+    return transformer.apply(transform).then((_) {
+      expect(transform.outs, hasLength(1));
+      expect(transform.outs[0].id, id);
+      return transform.outs.first.readAsString();
+    });
+  });
+}
+
+class _MockTransform implements Transform {
+  List<Asset> outs = [];
+  Asset _asset;
+  AssetId get primaryId => _asset.id;
+  TransformLogger logger = new TransformLogger(false);
+  Future<Asset> get primaryInput => new Future.value(_asset);
+
+  _MockTransform(this._asset);
+  Future<Asset> getInput(Asset id) {
+    if (id == primaryId) return primaryInput;
+    fail();
+  }
+
+  void addOutput(Asset output) {
+    outs.add(output);
+  }
+}