feat(router): add link that support only absolute urls

modules/angular2/test/alt_router/link_spec.ts

@@ -0,0 +1,67 @@
+import {
+  ComponentFixture,
+  AsyncTestCompleter,
+  TestComponentBuilder,
+  beforeEach,
+  ddescribe,
+  xdescribe,
+  describe,
+  el,
+  expect,
+  iit,
+  inject,
+  beforeEachProviders,
+  it,
+  xit
+} from 'angular2/testing_internal';
+
+import {RouteSegment, UrlSegment, Tree} from 'angular2/src/alt_router/segments';
+import {link} from 'angular2/src/alt_router/link';
+import {DefaultRouterUrlSerializer} from 'angular2/src/alt_router/router_url_serializer';
+
+export function main() {
+  describe('link', () => {
+    let parser = new DefaultRouterUrlSerializer();
+
+    it("should return the original tree when given an empty array", () => {
+      let p = parser.parse("/");
+      let t = link(s(p.root), p, []);
+      expect(t).toBe(p);
+    });
+
+    it("should support going to root", () => {
+      let p = parser.parse("/");
+      let t = link(s(p.root), p, ["/"]);
+      expect(parser.serialize(t)).toEqual("");
+    });
+
+    it("should support positional params", () => {
+      let p = parser.parse("/");
+      let t = link(s(p.root), p, ["/one", 11, "two", 22]);
+      expect(parser.serialize(t)).toEqual("/one/11/two/22");
+    });
+
+    it("should preserve route siblings when changing the main route", () => {
+      let p = parser.parse("/a/11/b(c)");
+      let t = link(s(p.root), p, ["/a", 11, 'd']);
+      expect(parser.serialize(t)).toEqual("/a/11/d(aux:c)");
+    });
+
+    it("should preserve route siblings when changing a aux route", () => {
+      let p = parser.parse("/a/11/b(c)");
+      let t = link(s(p.root), p, ["/a", 11, 'aux:d']);
+      expect(parser.serialize(t)).toEqual("/a/11/b(aux:d)");
+    });
+
+
+    it('should update parameters', () => {
+      let p = parser.parse("/a;aa=11");
+      let t = link(s(p.root), p, ["/a", {aa: 22, bb: 33}]);
+      expect(parser.serialize(t)).toEqual("/a;aa=22;bb=33");
+    });
+  });
+}
+
+function s(u: UrlSegment): RouteSegment {
+  return new RouteSegment([u], {}, null, null, null);
+}