angular-docs-cn/modules/angular2/test/di/async_spec.ts

import {
  AsyncTestCompleter,
  beforeEach,
  ddescribe,
  describe,
  expect,
  iit,
  inject,
  it,
  xit,
} from 'angular2/test_lib';
import {Injector, bind, Key} from 'angular2/di';
import {Inject, InjectPromise, Injectable} from 'angular2/src/di/decorators';
import {Promise, PromiseWrapper} from 'angular2/src/facade/async';
import {stringify} from 'angular2/src/facade/lang';

class UserList {}

function fetchUsers() {
  return PromiseWrapper.resolve(new UserList());
}

class SynchronousUserList {}

@Injectable()
class UserController {
  list: UserList;
  constructor(list: UserList) { this.list = list; }
}

@Injectable()
class AsyncUserController {
  userList;
  constructor(@InjectPromise(UserList) userList) { this.userList = userList; }
}

export function main() {
  describe("async injection", function() {

    describe("asyncGet", function() {
      it('should return a promise', function() {
        var injector = Injector.resolveAndCreate([bind(UserList).toAsyncFactory(fetchUsers)]);
        var p = injector.asyncGet(UserList);
        expect(p).toBePromise();
      });

      it('should return a promise when the binding is sync', function() {
        var injector = Injector.resolveAndCreate([SynchronousUserList]);
        var p = injector.asyncGet(SynchronousUserList);
        expect(p).toBePromise();
      });

      it("should return a promise when the binding is sync (from cache)", function() {
        var injector = Injector.resolveAndCreate([UserList]);
        expect(injector.get(UserList)).toBeAnInstanceOf(UserList);
        expect(injector.asyncGet(UserList)).toBePromise();
      });

      it('should return the injector', inject([AsyncTestCompleter], (async) => {
           var injector = Injector.resolveAndCreate([]);
           var p = injector.asyncGet(Injector);
           p.then(function(injector) {
             expect(injector).toBe(injector);
             async.done();
           });
         }));

      it('should return a promise when instantiating a sync binding ' +
             'with an async dependency',
         inject([AsyncTestCompleter], (async) => {
           var injector =
               Injector
                   .resolveAndCreate([bind(UserList).toAsyncFactory(fetchUsers), UserController]);

           injector.asyncGet(UserController)
               .then(function(userController) {
                 expect(userController).toBeAnInstanceOf(UserController);
                 expect(userController.list).toBeAnInstanceOf(UserList);
                 async.done();
               });
         }));

      it("should create only one instance (async + async)",
         inject([AsyncTestCompleter], (async) => {
           var injector = Injector.resolveAndCreate([bind(UserList).toAsyncFactory(fetchUsers)]);

           var ul1 = injector.asyncGet(UserList);
           var ul2 = injector.asyncGet(UserList);

           PromiseWrapper.all([ul1, ul2])
               .then(function(uls) {
                 expect(uls[0]).toBe(uls[1]);
                 async.done();
               });
         }));

      it("should create only one instance (sync + async)", inject([AsyncTestCompleter], (async) => {
           var injector = Injector.resolveAndCreate([UserList]);

           var promise = injector.asyncGet(UserList);
           var ul = injector.get(UserList);

           expect(promise).toBePromise();
           expect(ul).toBeAnInstanceOf(UserList);

           promise.then(function(ful) {
             expect(ful).toBe(ul);
             async.done();
           });
         }));

      it('should show the full path when error happens in a constructor',
         inject([AsyncTestCompleter], (async) => {
           var injector = Injector.resolveAndCreate([
             UserController,
             bind(UserList).toAsyncFactory(function() { throw "Broken UserList"; })
           ]);

           var promise = injector.asyncGet(UserController);
           PromiseWrapper.then(promise, null, function(e) {
             expect(e.message).toContain(
                 `Error during instantiation of UserList! (${stringify(UserController)} -> UserList)`);
             async.done();
           });
         }));
    });

    describe("get", function() {
      it('should throw when instantiating an async binding', function() {
        var injector = Injector.resolveAndCreate([bind(UserList).toAsyncFactory(fetchUsers)]);

        expect(() => injector.get(UserList))
            .toThrowError(
                'Cannot instantiate UserList synchronously. It is provided as a promise!');
      });

      it('should throw when instantiating a sync binding with an async dependency', function() {
        var injector =
            Injector.resolveAndCreate([bind(UserList).toAsyncFactory(fetchUsers), UserController]);

        expect(() => injector.get(UserController))
            .toThrowError(new RegExp(
                'Cannot instantiate UserList synchronously. It is provided as a promise!'));
      });

      it('should not throw when instantiating a sync binding with a resolved async dependency',
         inject([AsyncTestCompleter], (async) => {
           var injector =
               Injector
                   .resolveAndCreate([bind(UserList).toAsyncFactory(fetchUsers), UserController]);

           injector.asyncGet(UserList).then((_) => {
             expect(() => { injector.get(UserController); }).not.toThrow();
             async.done();
           });
         }));

      it('should resolve synchronously when an async dependency requested as a promise',
         function() {
           var injector = Injector.resolveAndCreate(
               [bind(UserList).toAsyncFactory(fetchUsers), AsyncUserController]);
           var controller = injector.get(AsyncUserController);

           expect(controller).toBeAnInstanceOf(AsyncUserController);
           expect(controller.userList).toBePromise();
         });

      it('should wrap sync dependencies into promises if required', function() {
        var injector = Injector.resolveAndCreate(
            [bind(UserList).toFactory(() => new UserList()), AsyncUserController]);
        var controller = injector.get(AsyncUserController);

        expect(controller).toBeAnInstanceOf(AsyncUserController);
        expect(controller.userList).toBePromise();
      });
    });
  });
}