angular-docs-cn/modules/@angular/common/test/pipes/json_pipe_spec.ts

import {
  ddescribe,
  describe,
  it,
  iit,
  xit,
  expect,
  beforeEach,
  afterEach,
  AsyncTestCompleter,
  inject,
  TestComponentBuilder
} from 'angular2/testing_internal';
import {Json, RegExp, NumberWrapper, StringWrapper} from 'angular2/src/facade/lang';

import {Component} from 'angular2/core';
import {JsonPipe} from 'angular2/common';

export function main() {
  describe("JsonPipe", () => {
    var regNewLine = '\n';
    var inceptionObj;
    var inceptionObjString;
    var pipe;

    function normalize(obj: string): string { return StringWrapper.replace(obj, regNewLine, ''); }

    beforeEach(() => {
      inceptionObj = {dream: {dream: {dream: 'Limbo'}}};
      inceptionObjString = "{\n" + "  \"dream\": {\n" + "    \"dream\": {\n" +
                           "      \"dream\": \"Limbo\"\n" + "    }\n" + "  }\n" + "}";


      pipe = new JsonPipe();
    });

    describe("transform", () => {
      it("should return JSON-formatted string",
         () => { expect(pipe.transform(inceptionObj)).toEqual(inceptionObjString); });

      it("should return JSON-formatted string even when normalized", () => {
        var dream1 = normalize(pipe.transform(inceptionObj));
        var dream2 = normalize(inceptionObjString);
        expect(dream1).toEqual(dream2);
      });

      it("should return JSON-formatted string similar to Json.stringify", () => {
        var dream1 = normalize(pipe.transform(inceptionObj));
        var dream2 = normalize(Json.stringify(inceptionObj));
        expect(dream1).toEqual(dream2);
      });
    });

    describe('integration', () => {
      it('should work with mutable objects',
         inject([TestComponentBuilder, AsyncTestCompleter], (tcb: TestComponentBuilder, async) => {
           tcb.createAsync(TestComp).then((fixture) => {
             let mutable: number[] = [1];
             fixture.debugElement.componentInstance.data = mutable;
             fixture.detectChanges();
             expect(fixture.debugElement.nativeElement).toHaveText("[\n  1\n]");

             mutable.push(2);
             fixture.detectChanges();
             expect(fixture.debugElement.nativeElement).toHaveText("[\n  1,\n  2\n]");

             async.done();
           });
         }));
    });
  });
}

@Component({selector: 'test-comp', template: '{{data | json}}', pipes: [JsonPipe]})
class TestComp {
  data: any;
}