What's new in Zone.js

@JiaLiPassion

Who am I

Name: LI JIA
Company: Sylabs
Zone.js: Collaborator
Angular: Contributor

Agenda

What's Zone.js
Zone.js in Angular
What's new in zone.js will help you in angular

What is Zone.js

A Zone is an execution context that persists across async tasks.

Created by Brian Ford inspired by Dart.

What zone.js can do

Provide execution context
Provide async task lifecycle interceptable hook
Provide async error handler

Execution Context

Zone.current.fork({name: 'a'})
   .run(function() {
      setTimeout(function （） {
        // Zone.current is a
      }, 100);
      setTimeout(function() {
        // Zone.current is a
      }, 200);
});

function outside() {
   // Execution context of outside
   function inside1() {
       // Execution context of inside1
   }

   function inside2() {
       // Execution context of inside2
   }
}

LifeCycle Interceptable Hooks

onFork
onIntercept
onInvoke
onHandleError
onScheduleTask
onInvokeTask
onCancelTask
onHasTask

setTimeout

setTimeout(function() {
  console.log('callback invoked');
}, 1000);

setTimeout in Zone

var zone = Zone.current.fork({
  name: 'hook',
  onScheduleTask: ...,
  onInvokeTask: ....,
  onHasTask: ...
});
zone.run(() => {
  setTimeout(() => {
    console.log('timer callback invoked');
  }, 100);
});

Zone.js Event loop Demo

https://zone-ebb17.firebaseapp.com/

Async Error Handling

Zone.current.fork(
  {
    name: 'error',
    onHandleError: (delegate, curr, target, error) => {
       logger.error(error);
       return delegate.handleError(target, error);
    }
}).runGuarded(() => {
    setTimeout(() => {
       throw new Error('timeout error');
    });
    setTimeout(() => {
       throw new Error('another timeout error');
    });
});

Implementation: Mokey-Patch

const nativeTimeout = window.setTimeout;
window.setTimeout = function(callback) {
  const zone = Zone.current;
  const wrappedCallback = function() {
     zone.onInvokeTask('setTimeout'); // invoke hook
     return callback.apply(this, arguments);
  }
  zone.onScheduleTask('setTimeout');  // schedule hook
  nativeTimeout.apply(this, wrappedCallback);
}

When should we use Zone

Test
- Sync(Disallow Async)
- Async(Auto done, Auto cleanup)
- FakeAsync()
Debug
- LongStackTrace
- Task Tracing
Performance measure
Framework AutoRender
User Action Tracing
Resource Releasing

Zone.js in Angular

Change Detection

AsyncTest

FakeAsyncTest

SyncTest

Error Handling

Debug/Tracing

Zone.js in Angular

DOM API

setTimeout

Promise

EventTarget

...

Zone.js

Monkey-Patch

Angular

What's new

Performance
Promise
Error handling
Electron
More APIs support
Test
Angular Elements (Proposal)

Performance

Modularization
Event
Native Delegate

Modularization

Timer

Promise

EventTarget

requestAnimationFrame

...

Notification

MediaQuery

UserMedia

...

~~requestAnimationFrame~~

__Zone_disable_requestAnimationFrame=true

Event

__zone_symbol__BLACK_LISTED_EVENTS = ['scroll', 'mousemove'];



@HostListener('window:mousemove.nozone')
mouseMoveListener() {
  // will not in ngZone.
} 

<div (scroll.nozone)="scrollHandler();"></div>

Proposal?

Native Delegate

declare let Zone: any;
(window as any)[Zone.__symbol__('setTimeout')](() => {
  // will not in zone.
}, 100);

Promise

Pass Promise A+ Test
Support Promise.prototype.finally
Support Bluebird
- All Bluebird specified APIs will in zone
No more 'Zone.js has detected that ZoneAwarePromise `(window|global).Promise` has been overwritten ' error.
No more 'Zone already loaded' error. (proposal)

import 'zone.js/dist/zone';
import 'core-js/promise';

Error Handling

import 'zone.js/dist/zone-error';

Error Handling

import 'zone.js/dist/zone-error';

class MyError extends Error {
}

try {
  throw new MyError('myError');
} catch (error: Error) {
  if (error instanceof MyError) {
    // do some special error handling
  }
}

(window as any).__Zone_Error_BlacklistedStackFrames_policy = 'disable'; // 'default', 'lazy'

Electron

import 'zone.js/dist/zone-mix';

import 'zone.js/dist/zone-patch-electron';

Browser
NodeJs

Menu
Screenshot
Shell
Main<->Render communication

More APIs Support

MediaQuery
Notification
RTCPeerConnction
ShadyDom
Cordova
ResizeObserver
SocketIO
UserMedia
Jsonp Helper

Test

Bundle
FakeAsync enhancement
Async enhancement
Jasmine/Mocha
Unified Test Lib

Zone.js can be a standalone test library.

Test Bundle

import 'zone.js/dist/long-stack-trace';
import 'zone.js/dist/proxy';
import 'zone.js/dist/sync-test';
import 'zone.js/dist/jasmine-patch';
import 'zone.js/dist/async-test';
import 'zone.js/dist/fake-async';
import 'zone.js/dist/promise-testing';

import 'zone.js/dist/zone-testing';

Test Bundle(Proposal)

import 'zone.js/dist/zone-testing';

describe('zone-testing', () => {
  it('fakeAsync', fakeAsyncTest(() => {
    tick(100);
    discardPeriodicTasks();
    flushMicrotasks();
  });
 
  it ('async', asyncTest(() => {}));
});

FakeAsync: Date.now

it('should advance Date when tick in fakeAsync', fakeAsync(() => {
    const start = Date.now();
    tick(100);
    const end = Date.now();
    expect(end - start).toBe(100);
}));

FakeAsync: jasmine.clock

beforeEach(() => {
      jasmine.clock().install();
});
afterEach(() => {
      jasmine.clock().uninstall();
});
it('should get date diff correctly', () => {  // we don't need fakeAsync here.
      // automatically run into fake async zone, because jasmine.clock() is installed.
      const start = Date.now();
      jasmine.clock().tick(100);
      const end = Date.now();
      expect(end - start).toBe(100);
});

__zone_symbol__fakeAsyncPatchLock

FakeAsync: rxjs.scheduler

it('rxjs scheduler should be advanced by tick in fakeAsync', fakeAsync(() => {
        observable.delay(1000).subscribe(v => {
          result = v;
        });
        expect(result).toBeNull();
        testZoneSpec.tick(1000);
        expect(result).toBe('hello');
}));

Better timeout message

it('should timeout', async(() => {
    setTimeout(() => {}, 10000);
    fixture.whenStable(() => {});
}));

Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL.
--Pendng async tasks are: [type: macroTask, source: setTimeout, args: {handleId:3,isPeriodic:false,delay:10000,args:[]}

Jasmine 3.x/Mocha 5.x

Unified zone-testing

Can auto detect Test Framework
Can write mixed style test cases at the same time.
- Jasmine
- mocha
- jest

Unify TDD/BDD I/F

describe('BDD style', () => {});

xdescribe('BDD style', () => {});

suite('mocha style', () => {});

describe('', () => {
  beforeEach(() => {});
  suiteSetup(() => {});
  before(() => {});
  beforeAll(() => {});
});

describe('', () => {
  it('case', () => {});
  xit('case', () => {});
  it.skip('mocha skip', () => {});
  it.only('mocha only', () => {});
  specify('mocha specify', () => {});
});

Jasmine	Mocha	Jest
beforeAll	before	beforeAll
afterAll	after	afterAll
xdescribe	describe.skip	describe.skip
fdescribe	describe.only	describe.only
xit	it.skip	it.skip
fit	it.only	it.only

Mocha BDD I/F

Specify, suite, suiteSetup, suiteTearDown...

Unify expect

it ('expect', () => {
  expect(a).toEqual('test');  // jasmine
  expect(b).toBeInstanceOf(BType); // jest
  expect(Promise.resolve('lemon')).resolves.toBe('lemon'); // jest 
  const expected = [
      expect.stringMatching(/^Alic/),
      expect.stringMatching(/^[BR]ob/),
  ];
  expect(['Alicia', 'Roberto', 'Evelina']).toEqual(expect.arrayContaining(expected));  // jest
  const onPress = {x: 100, y: 200, z: 300};
  expect(onPress).toEqual(expect.objectContaining({
        x: expect.any(Number),
        y: expect.any(Number),
  }), ); // jest
  // ...
});

Unify spy

it ('expect', async() => {
  const spy = jasmine.createSpy();
  const spy1 = spyOn(obj);
  const spy2 = jest.mockFn();
  const myMockFn = jest.fn(() => 'default')
                  .mockImplementationOnce(() => 'first call')
                  .mockImplementationOnce(() => 'second call'); // jest
   const asyncMock = jest.fn()
                  .mockResolvedValue('default');
   expect(await asyncMock()).toEqual('default'); // jest
});

Unify Fake Timer

describe('', () => {
  beforeEach(() => jasmine.clock().install);
  afterEach(() => jasmine.clock().uninstall);
});

describe('', () => {
  beforeEach(() => {jest.useFakeTimers()});
  afterEach(() => {jest.resetFakeTimers();});
});

Angular Elements (Scoped Zone Proposal)

Web App

JQuery

React

Angular Elements

Zone.js

Update recently for Angular Elements

Custom Element V1 Support
Support loading Zone.js multiple times
Optimized root zone
rxjs 6/typescript 3

Update recently for Angular Elements

async function test() {
  return 1; 
}

async function main() {
  console.log('before await', Zone.current.name);
  await test();
  console.log('after await', Zone.current.name);
}

Zone.current.fork({name: 'test'}).run(main);

Thank You!

https://github.com/angular/zone.js
@JiaLiPassion

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By jiali

devtv

2,050

What's new in Zone.js

Who am I

Agenda

What is Zone.js

What zone.js can do

Execution Context

LifeCycle Interceptable Hooks

setTimeout

setTimeout in Zone

Zone.js Event loop Demo

Async Error Handling

Implementation: Mokey-Patch

When should we use Zone

Zone.js in Angular

Zone.js in Angular

What's new

Performance

Modularization

Event

Native Delegate

Promise

Error Handling

Error Handling

Electron

More APIs Support

Test

Test Bundle

Test Bundle(Proposal)

FakeAsync: Date.now

FakeAsync: jasmine.clock

FakeAsync: rxjs.scheduler

Better timeout message

Jasmine 3.x/Mocha 5.x

Unified zone-testing

Unify TDD/BDD I/F

Unify expect

Unify spy

Unify Fake Timer

Angular Elements (Scoped Zone Proposal)

Update recently for Angular Elements

Update recently for Angular Elements

Thank You!

devtv

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