angular-docs-cn/packages/platform-browser/test/browser/transfer_state_spec.ts

/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */


import {TestBed} from '@angular/core/testing';
import {BrowserModule, BrowserTransferStateModule, TransferState} from '@angular/platform-browser';
import {StateKey, escapeHtml, makeStateKey, unescapeHtml} from '@angular/platform-browser/src/browser/transfer_state';
import {DOCUMENT} from '@angular/platform-browser/src/dom/dom_tokens';

(function(){
  function removeScriptTag(doc: Document, id: string) {
    const existing = doc.getElementById(id);
    if (existing) {
      doc.body.removeChild(existing);
    }
  }

  function addScriptTag(doc: Document, appId: string, data: {}) {
    const script = doc.createElement('script');
    const id = appId + '-state';
    script.id = id;
    script.setAttribute('type', 'application/json');
    script.textContent = escapeHtml(JSON.stringify(data));

    // Remove any stale script tags.
    removeScriptTag(doc, id);

    doc.body.appendChild(script);
  }

  describe('TransferState', () => {
    const APP_ID = 'test-app';
    let doc: Document;

    const TEST_KEY = makeStateKey<number>('test');
    const DELAYED_KEY = makeStateKey<string>('delayed');

    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          BrowserModule.withServerTransition({appId: APP_ID}),
          BrowserTransferStateModule,
        ]
      });
      doc = TestBed.get(DOCUMENT);
    });

    afterEach(() => { removeScriptTag(doc, APP_ID + '-state'); });

    it('is initialized from script tag', () => {
      addScriptTag(doc, APP_ID, {test: 10});
      const transferState: TransferState = TestBed.get(TransferState);
      expect(transferState.get(TEST_KEY, 0)).toBe(10);
    });

    it('is initialized to empty state if script tag not found', () => {
      const transferState: TransferState = TestBed.get(TransferState);
      expect(transferState.get(TEST_KEY, 0)).toBe(0);
    });

    it('supports adding new keys using set', () => {
      const transferState: TransferState = TestBed.get(TransferState);
      transferState.set(TEST_KEY, 20);
      expect(transferState.get(TEST_KEY, 0)).toBe(20);
      expect(transferState.hasKey(TEST_KEY)).toBe(true);
    });

    it('supports removing keys', () => {
      const transferState: TransferState = TestBed.get(TransferState);
      transferState.set(TEST_KEY, 20);
      transferState.remove(TEST_KEY);
      expect(transferState.get(TEST_KEY, 0)).toBe(0);
      expect(transferState.hasKey(TEST_KEY)).toBe(false);
    });

    it('supports serialization using toJson()', () => {
      const transferState: TransferState = TestBed.get(TransferState);
      transferState.set(TEST_KEY, 20);
      expect(transferState.toJson()).toBe('{"test":20}');
    });

    it('calls onSerialize callbacks when calling toJson()', () => {
      const transferState: TransferState = TestBed.get(TransferState);
      transferState.set(TEST_KEY, 20);

      let value = 'initial';
      transferState.onSerialize(DELAYED_KEY, () => value);
      value = 'changed';

      expect(transferState.toJson()).toBe('{"test":20,"delayed":"changed"}');
    });
  });

  describe('escape/unescape', () => {
    it('works with all escaped characters', () => {
      const testString = '</script><script>alert(\'Hello&\' + "World");';
      const testObj = {testString};
      const escaped = escapeHtml(JSON.stringify(testObj));
      expect(escaped).toBe(
          '{&q;testString&q;:&q;&l;/script&g;&l;script&g;' +
          'alert(&s;Hello&a;&s; + \\&q;World\\&q;);&q;}');

      const unescapedObj = JSON.parse(unescapeHtml(escaped));
      expect(unescapedObj['testString']).toBe(testString);
    });
  });
})();