Demonstrate tests for issue angular#14734

Author: BobChao87

src/ng/directive/ngModel.js

@@ -604,6 +604,7 @@ NgModelController.prototype = {
       var syncValidatorsValid = true;
       forEach(that.$validators, function(validator, name) {
         var result = validator(modelValue, viewValue);
+        // var result = Boolean(validator(modelValue, viewValue));
         syncValidatorsValid = syncValidatorsValid && result;
         setValidity(name, result);
       });

test/ng/directive/ngModelSpec.js

@@ -847,6 +847,74 @@ describe('ngModel', function() {
         expect(ctrl.$valid).toBe(true);
       });
 
+      // See also the test on L886.
+      fit('should demonstrate how synchronous validators work now', function() {
+        var curry = function(v) {
+          return function() {
+            return v;
+          };
+        };
+
+        var tester = function(v, e) {
+          ctrl.$modelValue = undefined;
+          ctrl.$validators.a = curry(v);
+
+          ctrl.$validate();
+          expect(ctrl.$valid).toBe(e);
+        };
+
+        // False tests
+        tester(false, false);
+        tester(undefined, undefined);
+        tester(null, true);
+        tester(0, true);
+        tester(NaN, true);
+        tester('', true);
+
+        // True tests
+        tester(true, true);
+        tester(1, true);
+        tester('0', true);
+        tester('false', true);
+        tester([], true);
+        tester({}, true);
+      });
+
+      // Flip this test with the one above (L851) as well as line L606 with L607 in `ngModel.js`
+      // The differences between the two would likely being a breaking change
+      // Though the feature it is breaking was undocumented.
+      xit('should demonstrate how synchronous validators will work after this change', function() {
+        var curry = function(v) {
+          return function() {
+            return v;
+          };
+        };
+
+        var tester = function(v, e) {
+          ctrl.$modelValue = undefined;
+          ctrl.$validators.a = curry(v);
+
+          ctrl.$validate();
+          expect(ctrl.$valid).toBe(e);
+        };
+
+        // False tests
+        tester(false, false);
+        tester(undefined, false);
+        tester(null, false);
+        tester(0, false);
+        tester(NaN, false);
+        tester('', false);
+
+        // True tests
+        tester(true, true);
+        tester(1, true);
+        tester('0', true);
+        tester('false', true);
+        tester([], true);
+        tester({}, true);
+      });
+
 
       it('should register invalid validations on the $error object', function() {
         var curry = function(v) {