feat(forms): add support for validations

modules/angular2/test/forms/model_spec.js

@@ -1,7 +1,28 @@
 import {ddescribe, describe, it, iit, xit, expect, beforeEach, afterEach, el} from 'angular2/test_lib';
 import {ControlGroup, Control} from 'angular2/forms';
+import * as validations from 'angular2/forms';
 
 export function main() {
+  describe("Control", () => {
+    describe("validator", () => {
+      it("should run validator with the initial value", () => {
+        var c = new Control("value", validations.required);
+        expect(c.valid).toEqual(true);
+      });
+
+      it("should rerun the validator when the value changes", () => {
+        var c = new Control("value", validations.required);
+        c.updateValue(null);
+        expect(c.valid).toEqual(false);
+      });
+
+      it("should return errors", () => {
+        var c = new Control(null, validations.required);
+        expect(c.errors).toEqual({"required" : true});
+      });
+    });
+  });
+
   describe("ControlGroup", () => {
     describe("value", () => {
       it("should be the reduced value of the child controls", () => {
@@ -17,5 +38,27 @@ export function main() {
         expect(g.value).toEqual({})
       });
     });
+
+    describe("validator", () => {
+      it("should run the validator with the initial value", () => {
+        var g = new ControlGroup({
+          "one": new Control(null, validations.required)
+        });
+
+        expect(g.valid).toEqual(false);
+
+        expect(g.errors).toEqual({"one": {"required" : true}});
+      });
+
+      it("should run the validator with the value changes", () => {
+        var c = new Control(null, validations.required);
+        var g = new ControlGroup({"one": c});
+
+        c.updateValue("some value");
+
+        expect(g.valid).toEqual(true);
+        expect(g.errors).toEqual(null);
+      });
+    });
   });
 }