Refactor of PolymerExpressions. Adds "as" expressions.

pkg/polymer_expressions/test/syntax_test.dart

Index: pkg/polymer_expressions/test/syntax_test.dart
diff --git a/pkg/polymer_expressions/test/syntax_test.dart b/pkg/polymer_expressions/test/syntax_test.dart
index 5d15e172c5eb6e66849d7a697b6ecbcf02725f7e..d4f8d9e9a95a252cb386b78eac7488fd7759928f 100644
--- a/pkg/polymer_expressions/test/syntax_test.dart
+++ b/pkg/polymer_expressions/test/syntax_test.dart
@@ -8,105 +8,602 @@ import 'dart:html';
 import 'package:observe/observe.dart';
 import 'package:observe/mirrors_used.dart'; // make test smaller.
 import 'package:polymer_expressions/polymer_expressions.dart';
+import 'package:polymer_expressions/eval.dart';
 import 'package:template_binding/template_binding.dart';
 import 'package:unittest/html_config.dart';
 import 'package:unittest/unittest.dart';
+import 'package:smoke/mirrors.dart' as smoke;
+
+class TestScopeFactory implements ScopeFactory {
+  int scopeCount = 0;
+
+  modelScope({Object model, Map<String, Object> variables}) {
+    scopeCount++;
+    return new Scope(model: model, variables: variables);
+  }
+
+  childScope(Scope parent, String name, Object value) {
+    scopeCount++;
+    return parent.childScope(name, value);
+  }
+}
 
 main() {
   useHtmlConfiguration();
+  smoke.useMirrors();
 
   group('PolymerExpressions', () {
-    var testDiv;
+    DivElement testDiv;
+    TestScopeFactory testScopeFactory;
 
     setUp(() {
       document.body.append(testDiv = new DivElement());
+      testScopeFactory = new TestScopeFactory();
     });
 
     tearDown(() {
-      testDiv.firstChild.remove();
+      testDiv.children.clear();
       testDiv = null;
     });
 
-    test('should make two-way bindings to inputs', () {
-      testDiv.nodes.add(new Element.html('''
-          <template id="test" bind>
-            <input id="input" value="{{ firstName }}">
-          </template>'''));
-      var person = new Person('John', 'Messerly', ['A', 'B', 'C']);
-      templateBind(querySelector('#test'))
-          ..bindingDelegate = new PolymerExpressions()
-          ..model = person;
-      return new Future(() {}).then((_) {
-        InputElement input = querySelector('#input');
-        expect(input.value, 'John');
-        input.focus();
-        input.value = 'Justin';
-        input.blur();
-        var event = new Event('change');
-        // TODO(justin): figure out how to trigger keyboard events to test
-        // two-way bindings
+    Future<Element> setUpTest(String html, {model, Map globals}) {
+      var tag = new Element.html(html,
+          treeSanitizer: new NullNodeTreeSanitizer());
+
+      // make sure templates behave in the polyfill
+      TemplateBindExtension.bootstrap(tag);
+
+      templateBind(tag)
+        ..bindingDelegate = new PolymerExpressions(globals: globals,
+            scopeFactory: testScopeFactory)
+        ..model = model;
+      testDiv.children.clear();
+      testDiv.append(tag);
+      return waitForChange(testDiv);
+    }
+
+    group('scope creation', () {
+      // These tests are sensitive to some internals of the implementation that
+      // might not be visible to applications, but are useful for verifying that
+      // that we're not creating too many Scopes.
+
+      // The reason that we create two Scopes in the cases with one binding is
+      // that <template bind> has one scope for the context to evaluate the bind
+      // binding in, and another scope for the bindings inside the template.
+
+      // We could try to optimize the outer scope away in cases where the
+      // expression is empty, but there are a lot of special cases in the
+      // syntax code already.
+      test('should create one scope for a single binding', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].text, 'a');
+          expect(testScopeFactory.scopeCount, 1);
+        }));
+
+      test('should only create a single scope for two bindings', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+              <div>{{ data }}</div>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 3);
+          expect(testDiv.children[1].text, 'a');
+          expect(testDiv.children[2].text, 'a');
+          expect(testScopeFactory.scopeCount, 1);
+        }));
+
+      test('should create a new scope for a bind/as binding', () {
+        return setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+              <template bind="{{ data as a }}" id="inner">
+                <div>{{ a }}</div>
+                <div>{{ data }}</div>
+              </template>
+            </template>''',
+            model: new Model('foo'))
+        .then((_) {
+          expect(testDiv.children.length, 5);
+          expect(testDiv.children[1].text, 'foo');
+          expect(testDiv.children[3].text, 'foo');
+          expect(testDiv.children[4].text, 'foo');
+          expect(testScopeFactory.scopeCount, 2);
+        });
       });
+
+      test('should create scopes for a repeat/in binding', () {
+        return setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+              <template repeat="{{ i in items }}" id="inner">
+                <div>{{ i }}</div>
+                <div>{{ data }}</div>
+              </template>
+            </template>''',
+            model: new Model('foo'), globals: {'items': ['a', 'b', 'c']})
+        .then((_) {
+          expect(testDiv.children.length, 9);
+          expect(testDiv.children[1].text, 'foo');
+          expect(testDiv.children[3].text, 'a');
+          expect(testDiv.children[4].text, 'foo');
+          expect(testDiv.children[5].text, 'b');
+          expect(testDiv.children[6].text, 'foo');
+          expect(testDiv.children[7].text, 'c');
+          expect(testDiv.children[8].text, 'foo');
+          // 1 scopes for <template bind>, 1 for each repeat
+          expect(testScopeFactory.scopeCount, 4);
+        });
+      });
+
+
     });
 
-    test('should handle null collections in "in" expressions', () {
-      testDiv.nodes.add(new Element.html('''
-          <template id="test" bind>
-            <template repeat="{{ item in items }}">
-              {{ item }}
-            </template>
-          </template>'''));
-      templateBind(querySelector('#test')).bindingDelegate =
-          new PolymerExpressions(globals: {'items': null});
-      // the template should be the only node
-      expect(testDiv.nodes.length, 1);
-      expect(testDiv.nodes[0].id, 'test');
+    group('with template bind', () {
+
+      test('should show a simple binding on the model', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].text, 'a');
+        }));
+
+      test('should handle an empty binding on the model', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ }}</div>
+            </template>''',
+            model: 'a')
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].text, 'a');
+        }));
+
+      test('should show a simple binding to a global', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ a }}</div>
+            </template>''',
+            globals: {'a': '123'})
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].text, '123');
+        }));
+
+      test('should show an expression binding', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ data + 'b' }}</div>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].text, 'ab');
+        }));
+
+      test('should handle an expression in the bind attribute', () =>
+        setUpTest('''
+            <template id="test" bind="{{ data }}">
+              <div>{{ this }}</div>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].text, 'a');
+        }));
+
+      test('should handle a nested template with an expression in the bind '
+          'attribute', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <template id="inner" bind="{{ data }}">
+                <div>{{ this }}</div>
+              </template>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 3);
+          expect(testDiv.children[2].text, 'a');
+        }));
+
+
+      test('should handle an "as" expression in the bind attribute', () =>
+        setUpTest('''
+            <template id="test" bind="{{ data as a }}">
+              <div>{{ data }}b</div>
+              <div>{{ a }}c</div>
+            </template>''',
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children.length, 3);
+          expect(testDiv.children[1].text, 'ab');
+          expect(testDiv.children[2].text, 'ac');
+        }));
+
+      // passes safari
+      test('should not resolve names in the outer template from within a nested'
+          ' template with a bind binding', () {
+        var completer = new Completer();
+        var bindingErrorHappened = false;
+        var templateRendered = false;
+        maybeComplete() {
+          if (bindingErrorHappened && templateRendered) {
+            completer.complete(true);
+          }
+        }
+        runZoned(() {
+          setUpTest('''
+              <template id="test" bind>
+                <div>{{ data }}</div>
+                <div>{{ b }}</div>
+                <template id="inner" bind="{{ b }}">
+                  <div>{{ data }}</div>
+                  <div>{{ b }}</div>
+                  <div>{{ this }}</div>
+                </template>
+              </template>''',
+              model: new Model('foo'), globals: {'b': 'bbb'})
+          .then((_) {
+            expect(testDiv.children[0].text, '');
+            expect(testDiv.children[1].text, 'foo');
+            expect(testDiv.children[2].text, 'bbb');
+            // Something very strage is happening in the template bindings
+            // polyfill, and the template is being stamped out, inside the
+            // template tag (which shouldn't happen), and outside the template
+            //expect(testDiv.children[3].text, '');
+            expect(testDiv.children[3].tagName.toLowerCase(), 'template');
+            expect(testDiv.children[4].text, '');
+            expect(testDiv.children[5].text, 'bbb');
+            expect(testDiv.children[6].text, 'bbb');
+            templateRendered = true;
+            maybeComplete();
+          });
+        }, onError: (e, s) {
+          expect('$e', contains('data'));
+          bindingErrorHappened = true;
+          maybeComplete();
+        });
+        return completer.future;
+      });
+
+      // passes safari
+      test('should shadow names in the outer template from within a nested '
+          'template', () =>
+          setUpTest('''
+            <template id="test" bind>
+              <div>{{ a }}</div>
+              <div>{{ b }}</div>
+              <template bind="{{ b as a }}">
+                <div>{{ a }}</div>
+                <div>{{ b }}</div>
+              </template>
+            </template>''',
+            globals: {'a': 'aaa', 'b': 'bbb'})
+        .then((_) {
+          expect(testDiv.children[0].text, '');
+          expect(testDiv.children[1].text, 'aaa');
+          expect(testDiv.children[2].text, 'bbb');
+          expect(testDiv.children[3].tagName.toLowerCase(), 'template');
+          expect(testDiv.children[4].text, 'bbb');
+          expect(testDiv.children[5].text, 'bbb');
+        }));
+
     });
 
-    test('should silently handle bad variable names', () {
-      var completer = new Completer();
-      runZoned(() {
-        testDiv.nodes.add(new Element.html('''
-            <template id="test" bind>{{ foo }}</template>'''));
-        templateBind(querySelector('#test'))
-            ..bindingDelegate = new PolymerExpressions()
-            ..model = [];
-        return new Future(() {});
-      }, onError: (e, s) {
-        expect('$e', contains('foo'));
-        completer.complete(true);
+    group('with template repeat', () {
+
+      // passes safari
+      test('should not resolve names in the outer template from within a nested'
+          ' template with a repeat binding', () {
+        var completer = new Completer();
+        var bindingErrorHappened = false;
+        var templateRendered = false;
+        maybeComplete() {
+          if (bindingErrorHappened && templateRendered) {
+            completer.complete(true);
+          }
+        }
+        runZoned(() {
+          setUpTest('''
+              <template id="test" bind>
+                <div>{{ data }}</div>
+                <template repeat="{{ items }}">
+                  <div>{{ }}{{ data }}</div>
+                </template>
+              </template>''',
+              globals: {'items': [1, 2, 3]},
+              model: new Model('a'))
+          .then((_) {
+            expect(testDiv.children[0].text, '');
+            expect(testDiv.children[1].text, 'a');
+            expect(testDiv.children[2].tagName.toLowerCase(), 'template');
+            expect(testDiv.children[3].text, '1');
+            expect(testDiv.children[4].text, '2');
+            expect(testDiv.children[5].text, '3');
+            templateRendered = true;
+            maybeComplete();
+          });
+        }, onError: (e, s) {
+          expect('$e', contains('data'));
+          bindingErrorHappened = true;
+          maybeComplete();
+        });
+        return completer.future;
+      });
+
+      test('should handle repeat/in bindings', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+              <template repeat="{{ item in items }}">
+                <div>{{ item }}{{ data }}</div>
+              </template>
+            </template>''',
+            globals: {'items': [1, 2, 3]},
+            model: new Model('a'))
+        .then((_) {
+          // expect 6 children: two templates, a div and three instances
+          expect(testDiv.children[0].text, '');
+          expect(testDiv.children[1].text, 'a');
+          expect(testDiv.children[2].tagName.toLowerCase(), 'template');
+          expect(testDiv.children[3].text, '1a');
+          expect(testDiv.children[4].text, '2a');
+          expect(testDiv.children[5].text, '3a');
+//          expect(testDiv.children.map((c) => c.text),
+//              ['', 'a', '', '1a', '2a', '3a']);
+        }));
+
+      test('should observe changes to lists in repeat bindings', () {
+        var items = new ObservableList.from([1, 2, 3]);
+        return setUpTest('''
+            <template id="test" bind>
+              <template repeat="{{ items }}">
+                <div>{{ }}</div>
+              </template>
+            </template>''',
+            globals: {'items': items},
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children[0].text, '');
+          expect(testDiv.children[1].tagName.toLowerCase(), 'template');
+          expect(testDiv.children[2].text, '1');
+          expect(testDiv.children[3].text, '2');
+          expect(testDiv.children[4].text, '3');
+//          expect(testDiv.children.map((c) => c.text),
+//              ['', '', '1', '2', '3']);
+          items.add(4);
+          return waitForChange(testDiv);
+        }).then((_) {
+          expect(testDiv.children[0].text, '');
+          expect(testDiv.children[1].tagName.toLowerCase(), 'template');
+          expect(testDiv.children[2].text, '1');
+          expect(testDiv.children[3].text, '2');
+          expect(testDiv.children[4].text, '3');
+          expect(testDiv.children[5].text, '4');
+//          expect(testDiv.children.map((c) => c.text),
+//              ['', '', '1', '2', '3', '4']);
+        });
+      });
+
+      test('should observe changes to lists in repeat/in bindings', () {
+        var items = new ObservableList.from([1, 2, 3]);
+        return setUpTest('''
+            <template id="test" bind>
+              <template repeat="{{ item in items }}">
+                <div>{{ item }}</div>
+              </template>
+            </template>''',
+            globals: {'items': items},
+            model: new Model('a'))
+        .then((_) {
+          expect(testDiv.children[0].text, '');
+          expect(testDiv.children[1].tagName.toLowerCase(), 'template');
+          expect(testDiv.children[2].text, '1');
+          expect(testDiv.children[3].text, '2');
+          expect(testDiv.children[4].text, '3');
+//          expect(testDiv.children.map((c) => c.text),
+//              ['', '', '1', '2', '3']);
+          items.add(4);
+          return waitForChange(testDiv);
+        }).then((_) {
+          expect(testDiv.children[0].text, '');
+          expect(testDiv.children[1].tagName.toLowerCase(), 'template');
+          expect(testDiv.children[2].text, '1');
+          expect(testDiv.children[3].text, '2');
+          expect(testDiv.children[4].text, '3');
+          expect(testDiv.children[5].text, '4');
+//          expect(testDiv.children.map((c) => c.text),
+//              ['', '', '1', '2', '3', '4']);
+        });
       });
-      return completer.future;
     });
-  });
-}
 
-@reflectable
-class Person extends ChangeNotifier {
-  String _firstName;
-  String _lastName;
-  List<String> _items;
+    group('with template if', () {
 
-  Person(this._firstName, this._lastName, this._items);
+      Future doTest(value, bool shouldRender) =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ data }}</div>
+              <template if="{{ show }}">
+                <div>{{ data }}</div>
+              </template>
+            </template>''',
+            globals: {'show': value},
+            model: new Model('a'))
+        .then((_) {
+          if (shouldRender) {
+            expect(testDiv.children.length, 4);
+            expect(testDiv.children[1].text, 'a');
+            expect(testDiv.children[3].text, 'a');
+          } else {
+            expect(testDiv.children.length, 3);
+            expect(testDiv.children[1].text, 'a');
+          }
+        });
 
-  String get firstName => _firstName;
+      test('should render for a true expression',
+          () => doTest(true, true));
 
-  void set firstName(String value) {
-    _firstName = notifyPropertyChange(#firstName, _firstName, value);
-  }
+      test('should treat a non-null expression as truthy',
+          () => doTest('a', true));
 
-  String get lastName => _lastName;
+      test('should treat an empty list as truthy',
+          () => doTest([], true));
 
-  void set lastName(String value) {
-    _lastName = notifyPropertyChange(#lastName, _lastName, value);
-  }
+      test('should handle a false expression',
+          () => doTest(false, false));
+
+      test('should treat null as falsey',
+          () => doTest(null, false));
+    });
 
-  String getFullName() => '$_firstName $_lastName';
+    group('error handling', () {
 
-  List<String> get items => _items;
+      test('should silently handle bad variable names', () {
+        var completer = new Completer();
+        runZoned(() {
+          testDiv.nodes.add(new Element.html('''
+              <template id="test" bind>{{ foo }}</template>'''));
+          templateBind(query('#test'))
+              ..bindingDelegate = new PolymerExpressions()
+              ..model = [];
+          return new Future(() {});
+        }, onError: (e, s) {
+          expect('$e', contains('foo'));
+          completer.complete(true);
+        });
+        return completer.future;
+      });
 
-  void set items(List<String> value) {
-    _items = notifyPropertyChange(#items, _items, value);
+      test('should handle null collections in "in" expressions', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <template repeat="{{ item in items }}">
+                {{ item }}
+              </template>
+            </template>''',
+            globals: {'items': null})
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[0].id, 'test');
+        }));
+
+    });
+
+    group('special bindings', () {
+
+      test('should handle class attributes with lists', ()  =>
+        setUpTest('''
+            <template id="test" bind>
+              <div class="{{ classes }}">
+            </template>''',
+            globals: {'classes': ['a', 'b']})
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].attributes['class'], 'a b');
+          expect(testDiv.children[1].classes, ['a', 'b']);
+        }));
+
+      test('should handle class attributes with maps', ()  =>
+        setUpTest('''
+            <template id="test" bind>
+              <div class="{{ classes }}">
+            </template>''',
+            globals: {'classes': {'a': true, 'b': false, 'c': true}})
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].attributes['class'], 'a c');
+          expect(testDiv.children[1].classes, ['a', 'c']);
+        }));
+
+      test('should handle style attributes with lists', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div style="{{ styles }}">
+            </template>''',
+            globals: {'styles': ['display: none', 'color: black']})
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].attributes['style'],
+              'display: none;color: black');
+        }));
+
+      test('should handle style attributes with maps', ()  =>
+        setUpTest('''
+            <template id="test" bind>
+              <div style="{{ styles }}">
+            </template>''',
+            globals: {'styles': {'display': 'none', 'color': 'black'}})
+        .then((_) {
+          expect(testDiv.children.length, 2);
+          expect(testDiv.children[1].attributes['style'],
+              'display: none;color: black');
+        }));
+    });
+
+    group('regression tests', () {
+
+      test('should bind to literals', () =>
+        setUpTest('''
+            <template id="test" bind>
+              <div>{{ 123 }}</div>
+              <div>{{ 123.456 }}</div>
+              <div>{{ "abc" }}</div>
+              <div>{{ true }}</div>
+              <div>{{ null }}</div>
+            </template>''',
+            globals: {'items': null})
+        .then((_) {
+          expect(testDiv.children.length, 6);
+          expect(testDiv.children[1].text, '123');
+          expect(testDiv.children[2].text, '123.456');
+          expect(testDiv.children[3].text, 'abc');
+          expect(testDiv.children[4].text, 'true');
+          expect(testDiv.children[5].text, '');
+        }));
+
+      });
+
+  });
+}
+
+Future<Element> waitForChange(Element e) {
+  var completer = new Completer<Element>();
+  new MutationObserver((mutations, observer) {
+    observer.disconnect();
+    completer.complete(e);
+  }).observe(e, childList: true);
+  return completer.future.timeout(new Duration(seconds: 1));
+}
+
+@reflectable
+class Model extends ChangeNotifier {
+  String _data;
+
+  Model(this._data);
+
+  String get data => _data;
+
+  void set data(String value) {
+    _data = notifyPropertyChange(#data, _data, value);
   }
 
-  String toString() => "Person(firstName: $_firstName, lastName: $_lastName)";
+  String toString() => "Model(data: $_data)";
 }
+
+class NullNodeTreeSanitizer implements NodeTreeSanitizer {
+
+  @override
+  void sanitizeTree(Node node) {}
+}