feat(ChangeDetector): When watching a methods colorization should not show up as changes

Closes #934

Author: mvuksano

lib/change_detection/dirty_checking_change_detector.dart

@@ -460,8 +460,15 @@ class DirtyCheckingRecord<H> implements Record<H>, WatchRecord<H> {
       _mode =  _MODE_MAP_FIELD_;
       _getter = null;
     } else {
-      _mode = _MODE_GETTER_;
-      _getter = _fieldGetterFactory.getter(obj, field);
+      if (_fieldGetterFactory.isMethod(obj, field)) {
+        _mode = _MODE_IDENTITY_;
+        previousValue = currentValue = _fieldGetterFactory.method(obj, field)(obj);
+        assert(previousValue is Function);
+      } else {
+        _mode = _MODE_GETTER_;
+        _getter = _fieldGetterFactory.getter(obj, field);
+        currentValue = _getter(obj);
+      }
     }
   }
 

lib/change_detection/dirty_checking_change_detector_dynamic.dart

@@ -13,12 +13,11 @@ import 'dart:mirrors';
 class DynamicFieldGetterFactory implements FieldGetterFactory {
   final isMethodInvoke = true;
 
-  bool isMethod(Object object, String name) {
-    try {
-      return method(object, name) != null;
-    } catch (e, s) {
-      return false;
-    }
+  isMethod(Object object, String name) {
+    var declaration = reflectClass(object.runtimeType).declarations[new Symbol(name)];
+    return declaration != null &&
+           declaration is MethodMirror &&
+           (declaration as MethodMirror).isRegularMethod;
   }
 
   Function method(Object object, String name) {

test/change_detection/dirty_checking_change_detector_spec.dart

@@ -4,6 +4,7 @@ import '../_specs.dart';
 import 'package:angular/change_detection/change_detection.dart';
 import 'package:angular/change_detection/dirty_checking_change_detector.dart';
 import 'package:angular/change_detection/dirty_checking_change_detector_static.dart';
+import 'package:angular/change_detection/dirty_checking_change_detector_dynamic.dart';
 import 'dart:collection';
 import 'dart:math';
 
@@ -14,19 +15,80 @@ void main() {
         "first": (o) => o.first,
         "age": (o) => o.age,
         "last": (o) => o.last,
-        "toString": (o) => o.toString
+        "toString": (o) => o.toString,
+        "isUnderAge": (o) => o.isUnderAge,
+        "isUnderAgeAsVariable": (o) => o.isUnderAgeAsVariable
     });
 
     beforeEach(() {
       detector = new DirtyCheckingChangeDetector<String>(getterFactory);
     });
 
     describe('StaticFieldGetterFactory', () {
+      DirtyCheckingChangeDetector<String> detector;
+      var user = new _User('Marko', 'Vuksanovic', 30);
+      FieldGetterFactory getterFactory = new StaticFieldGetterFactory({
+          "first": (o) => o.first,
+          "age": (o) => o.age,
+          "last": (o) => o.last,
+          "toString": (o) => o.toString,
+          "isUnderAge": (o) => o.isUnderAge,
+          "isUnderAgeAsVariable": (o) => o.isUnderAgeAsVariable,
+          "list": (o) => o.list,
+          "map": (o) => o.map
+      });
+
+      beforeEach(() {
+        detector = new DirtyCheckingChangeDetector<String>(getterFactory);
+      });
+
       it('should detect methods', () {
         var obj = new _User();
         expect(getterFactory.isMethod(obj, 'toString')).toEqual(true);
         expect(getterFactory.isMethod(obj, 'age')).toEqual(false);
       });
+
+      it('should return true is method is real method', () {
+        expect(getterFactory.isMethod(user, 'isUnderAge')).toEqual(true);
+      });
+
+      it('should return false is field is a function', () {
+        expect(getterFactory.isMethod(user, 'isUnderAgeAsVariable')).toEqual(false);
+      });
+
+      it('should return false is field is a list', () {
+        expect(getterFactory.isMethod(user, 'list')).toEqual(false);
+      });
+
+      it('should return false is field is a map', () {
+        expect(getterFactory.isMethod(user, 'map')).toEqual(false);
+      });
+    });
+
+    describe('Dynamic GetterFactory', () {
+      DirtyCheckingChangeDetector<String> detector;
+      var user = new _User('Marko', 'Vuksanovic', 30);
+      FieldGetterFactory getterFactory = new DynamicFieldGetterFactory();
+
+      beforeEach(() {
+        detector = new DirtyCheckingChangeDetector<String>(getterFactory);
+      });
+
+      it('should return true is method is real method', () {
+        expect(getterFactory.isMethod(user, 'isUnderAge')).toEqual(true);
+      });
+
+      it('should return false is field is a function', () {
+        expect(getterFactory.isMethod(user, 'isUnderAgeAsVariable')).toEqual(false);
+      });
+
+      it('should return false is field is a list', () {
+        expect(getterFactory.isMethod(user, 'list')).toEqual(false);
+      });
+
+      it('should return false is field is a map', () {
+        expect(getterFactory.isMethod(user, 'map')).toEqual(false);
+      });
     });
 
     describe('object field', () {
@@ -657,6 +719,39 @@ void main() {
       });
     });
 
+    describe('function watching', () {
+      it('should detect no changes when watching a function', () {
+        var user = new _User('marko', 'vuksanovic', 15);
+        Iterator changeIterator;
+
+        detector..watch(user, 'isUnderAge', null);
+        changeIterator = detector.collectChanges();
+        expect(changeIterator.moveNext()).toEqual(true);
+        expect(changeIterator.moveNext()).toEqual(false);
+
+        user.age = 17;
+        changeIterator = detector.collectChanges();
+        expect(changeIterator.moveNext()).toEqual(false);
+
+        user.age = 30;
+        changeIterator = detector.collectChanges();
+        expect(changeIterator.moveNext()).toEqual(false);
+      });
+
+      it('should detect change when watching a property function', () {
+        var user = new _User('marko', 'vuksanovic', 30);
+        Iterator changeIterator;
+
+        detector..watch(user, 'isUnderAgeAsVariable', null);
+        changeIterator = detector.collectChanges();
+        expect(changeIterator.moveNext()).toEqual(false);
+
+        user.isUnderAgeAsVariable = () => false;
+        changeIterator = detector.collectChanges();
+        expect(changeIterator.moveNext()).toEqual(true);
+      });
+    });
+
     describe('DuplicateMap', () {
       DuplicateMap map;
       beforeEach(() => map = new DuplicateMap());
@@ -693,8 +788,17 @@ class _User {
   String first;
   String last;
   num age;
+  var isUnderAgeAsVariable;
+  List<String> list = ['foo', 'bar', 'baz'];
+  Map map = {'foo': 'bar', 'baz': 'cux'};
 
-  _User([this.first, this.last, this.age]);
+  _User([this.first, this.last, this.age]) {
+    isUnderAgeAsVariable = isUnderAge;
+  }
+
+  bool isUnderAge() {
+    return age != null ? age < 18 : false;
+  }
 }
 
 Matcher toEqualCollectionRecord({collection, previous, additions, moves, removals}) =>

test/directive/ng_repeat_spec.dart

@@ -116,6 +116,16 @@ main() {
       expect(element.querySelectorAll('span').length).toEqual(2);
     });
 
+    it('should support function as a formatter', () {
+      scope.context['isEven'] = (num) => num % 2 == 0;
+      var element = compile(
+          '<div ng-show="true">'
+            '<span ng-repeat="r in [1, 2] | filter:isEven">{{r}}</span>'
+          '</div>');
+      scope.apply();
+      expect(element.text).toEqual('2');
+    });
+
 
     describe('track by', () {
       it(r'should track using expression function', () {