angular-docs-cn/modules/angular2/test/test_lib/fake_async_spec.js

import {
    AsyncTestCompleter,
    beforeEach,
    ddescribe,
    describe,
    expect,
    fakeAsync,
    flushMicrotasks,
    iit,
    inject,
    IS_DARTIUM,
    it,
    Log,
    tick,
    xit
} from 'angular2/test_lib';
import {PromiseWrapper} from 'angular2/src/facade/async';
import {BaseException, global} from 'angular2/src/facade/lang';
import {Parser} from 'angular2/change_detection';

export function main() {
  describe('fake async', () => {
    it('should run synchronous code', () => {
      var ran = false;
      fakeAsync(() => {
        ran = true;
      })();

      expect(ran).toEqual(true);
    });

    it('should pass arguments to the wrapped function', () => {
      fakeAsync((foo, bar) => {
        expect(foo).toEqual('foo');
        expect(bar).toEqual('bar');
      })('foo', 'bar');
    });

    it('should work with inject()', inject([Parser], fakeAsync((parser) => {
      expect(parser).toBeAnInstanceOf(Parser);
    })));

    if (!IS_DARTIUM) {
      it('should throw on nested calls', () => {
        // TODO(vicb): re-enable once the jasmine patch from zone.js is applied
        if (!IS_DARTIUM) return;
        expect(() => {
          fakeAsync(() => {
            fakeAsync(() => null)();
          })();
        }).toThrowError('fakeAsync() calls can not be nested');
      });
    }

    describe('Promise', () => {
      it('should run asynchronous code', fakeAsync(() => {
        var thenRan = false;
        PromiseWrapper.resolve(null).then((_) => {
          thenRan = true;
        });

        expect(thenRan).toEqual(false);

        flushMicrotasks();
        expect(thenRan).toEqual(true);
      }));

      it('should run chained thens', fakeAsync(() => {
        var log = new Log();

        PromiseWrapper
            .resolve(null)
            .then((_) => log.add(1))
            .then((_) => log.add(2));

        expect(log.result()).toEqual('');

        flushMicrotasks();
        expect(log.result()).toEqual('1; 2');
      }));

      it('should run Promise created in Promise', fakeAsync(() => {
        var log = new Log();

        PromiseWrapper
            .resolve(null)
            .then((_) => {
              log.add(1);
              PromiseWrapper.resolve(null).then((_) => log.add(2));
            });

        expect(log.result()).toEqual('');

        flushMicrotasks();
        expect(log.result()).toEqual('1; 2');
      }));

      // TODO(vicb): check why this doesn't work in JS - linked to open issues on GH ?
      xit('should complain if the test throws an exception during async calls', () => {
        expect(() => {
          fakeAsync(() => {
            PromiseWrapper.resolve(null).then((_) => {
              throw new BaseException('async');
            });
            flushMicrotasks();
          })();
        }).toThrowError('async');
      });

      it('should complain if a test throws an exception', () => {
        expect(() => {
          fakeAsync(() => {
            throw new BaseException('sync');
          })();
        }).toThrowError('sync');
      });

    });

    describe('timers', () => {
      it('should run queued zero duration timer on zero tick', fakeAsync(() => {
        var ran = false;
        PromiseWrapper.setTimeout(() => { ran = true }, 0);

        expect(ran).toEqual(false);

        tick();
        expect(ran).toEqual(true);
      }));


      it('should run queued timer after sufficient clock ticks', fakeAsync(() => {
        var ran = false;
        PromiseWrapper.setTimeout(() => { ran = true; }, 10);

        tick(6);
        expect(ran).toEqual(false);

        tick(6);
        expect(ran).toEqual(true);
      }));

      it('should run queued timer only once', fakeAsync(() => {
        var cycles = 0;
        PromiseWrapper.setTimeout(() => { cycles++; }, 10);

        tick(10);
        expect(cycles).toEqual(1);

        tick(10);
        expect(cycles).toEqual(1);

        tick(10);
        expect(cycles).toEqual(1);
      }));

      it('should not run cancelled timer', fakeAsync(() => {
        var ran = false;
        var id = PromiseWrapper.setTimeout(() => { ran = true; }, 10);
        PromiseWrapper.clearTimeout(id);

        tick(10);
        expect(ran).toEqual(false);
      }));

      it('should throw an error on dangling timers', () => {
        // TODO(vicb): https://github.com/google/quiver-dart/issues/248
        if (IS_DARTIUM) return;
        expect(() => {
          fakeAsync(() => {
            PromiseWrapper.setTimeout(() => { }, 10);
          })();
        }).toThrowError('1 timer(s) still in the queue.');
      });

      it('should throw an error on dangling periodic timers', () => {
        // TODO(vicb): https://github.com/google/quiver-dart/issues/248
        if (IS_DARTIUM) return;
        expect(() => {
          fakeAsync(() => {
            PromiseWrapper.setInterval(() => { }, 10);
          })();
        }).toThrowError('1 periodic timer(s) still in the queue.');
      });

      it('should run periodic timers', fakeAsync(() => {
        var cycles = 0;
        var id = PromiseWrapper.setInterval(() => { cycles++; }, 10);

        tick(10);
        expect(cycles).toEqual(1);

        tick(10);
        expect(cycles).toEqual(2);

        tick(10);
        expect(cycles).toEqual(3);

        PromiseWrapper.clearInterval(id);
      }));

      it('should not run cancelled periodic timer', fakeAsync(() => {
        var ran = false;
        var id = PromiseWrapper.setInterval(() => { ran = true; }, 10);
        PromiseWrapper.clearInterval(id);

        tick(10);
        expect(ran).toEqual(false);
      }));

      it('should be able to cancel periodic timers from a callback', fakeAsync(() => {
        if (global != null && global.jasmine) {
          // TODO(vicb): remove this when we switch to jasmine 2.3.3+
          // see https://github.com/jasmine/jasmine/commit/51462f369b376615bc9d761dcaa5d822ea1ff8ee
          return;
        }

        var cycles = 0;
        var id;

        id = PromiseWrapper.setInterval(() => {
          cycles++;
          PromiseWrapper.clearInterval(id);
        }, 10);

        tick(10);
        expect(cycles).toEqual(1);

        tick(10);
        expect(cycles).toEqual(1);
      }));

      it('should process microtasks before timers', fakeAsync(() => {
        var log = new Log();

        PromiseWrapper.resolve(null).then((_) => log.add('microtask'));

        PromiseWrapper.setTimeout(() => log.add('timer'), 9);

        var id = PromiseWrapper.setInterval(() => log.add('periodic timer'), 10);

        expect(log.result()).toEqual('');

        tick(10);
        expect(log.result()).toEqual('microtask; timer; periodic timer');

        PromiseWrapper.clearInterval(id);
      }));

      it('should process micro-tasks created in timers before next timers', fakeAsync(() => {
        var log = new Log();

        PromiseWrapper.resolve(null).then((_) => log.add('microtask'));

        PromiseWrapper.setTimeout(() => {
          log.add('timer');
          PromiseWrapper.resolve(null).then((_) => log.add('t microtask'));
        }, 9);

        var id = PromiseWrapper.setInterval(() => {
          log.add('periodic timer');
          PromiseWrapper.resolve(null).then((_) => log.add('pt microtask'));
        }, 10);

        tick(10);
        expect(log.result()).toEqual('microtask; timer; t microtask; periodic timer; pt microtask');

        tick(10);
        expect(log.result()).toEqual('microtask; timer; t microtask; periodic timer; pt microtask; periodic timer; pt microtask');

        PromiseWrapper.clearInterval(id);
      }));
    });

    describe('outside of the fakeAsync zone', () => {
      it('calling flushMicrotasks should throw', () => {
        expect(() => {
          flushMicrotasks();
        }).toThrowError('The code should be running in the fakeAsync zone to call this function');
      });

      it('calling tick should throw', () => {
        expect(() => {
          tick();
        }).toThrowError('The code should be running in the fakeAsync zone to call this function');
      });
    });

  });
}