spectacular/specs/units/promise.spec.coffee

Advanced BDD framework for CoffeeScript and JavaScript

describe spectacular.Promise, ->
  it -> should exist

  whenPass ->
    itsInstance -> should exist

    describe '.unit', ->
      it -> should exist
      whenPass ->
        itsReturn -> should exist

        context 'the returned promise', ->
          subject 'promise', -> spectacular.Promise.unit()

          it -> should be 'fulfilled'
          it -> should be 'resolved'
          its 'value', -> should equal 0

        context 'when called with a value', ->
          subject 'promise', -> spectacular.Promise.unit('foo')

          it -> should be 'fulfilled'
          its 'value', -> should equal 'foo'


    describe '.all', ->
      it -> should exist

      whenPass ->
        context 'when called with an array of promise', ->
          withParameters [
            spectacular.Promise.unit()
            spectacular.Promise.unit()
            spectacular.Promise.unit()
          ]

          itsReturn -> should exist
          itsReturn -> should be 'fulfilled'

        context 'with a failing promise', ->
          given 'failedPromise', ->
            promise = new spectacular.Promise
            promise.reject()
            promise

          withParameters ->
            [[
              spectacular.Promise.unit()
              spectacular.Promise.unit()
              @failedPromise
            ]]

          itsReturn -> should be 'rejected'

    describe '::isPending', ->
      itsReturn -> should equal true

    context 'when resolved', ->
      subject ->
        promise = spectacular.Promise.unit('a value')
        promise

      context 'trying to resolve the promise a second time', ->
        before -> @subject.resolve 'another value'

        specify 'the promise value', -> @subject.value.should equal 'a value'

      context 'trying to notify handlers a second time', ->
        before ->
          @notified = false
          @subject.fulfilledHandlers.push => @notified = true
          @subject.notifyHandlers()

        specify 'the handler shouldnt have been called', ->
          expect(@notified).to be false

    context 'when rejected', ->
      subject ->
        promise = new spectacular.Promise
        promise.reject 'a reason'
        promise

      context 'trying to reject the promise a second time', ->
        before -> @subject.reject 'another reason'

        specify 'the promise reason', -> @subject.reason.should equal 'a reason'
    context 'when chained using then', ->
      given 'firstPromise', -> new spectacular.Promise
      given 'secondPromise', -> @firstPromise.then ->
      given 'thirdPromise', -> @secondPromise.then ->

      context 'when the first promise is fulfilled', ->
        before -> @firstPromise.resolve()

        specify 'the secondPromise', -> @secondPromise.should be 'fulfilled'
        specify 'the thirdPromise', -> @thirdPromise.should be 'fulfilled'

      context 'when the first promise is rejected', ->
        before -> @firstPromise.reject('message')

        specify 'the secondPromise', -> @secondPromise.should be 'rejected'
        specify 'the thirdPromise', -> @thirdPromise.should be 'rejected'

      context 'and one of the factory return a promise', ->
        given 'firstPromise', -> new spectacular.Promise
        given 'returnedPromise', -> new spectacular.Promise
        given 'secondPromise', -> @firstPromise.then => @returnedPromise
        given 'thirdPromise', -> @secondPromise.then ->

        context 'when the first promise is fulfilled', ->
          before -> @firstPromise.resolve()

          specify 'the secondPromise', -> @secondPromise.shouldnt be 'fulfilled'
          specify 'the thirdPromise', -> @thirdPromise.should be 'pending'

          context 'and the returned promise is fulfilled', ->
            before -> @returnedPromise.resolve()

            specify 'the secondPromise', -> @secondPromise.should be 'fulfilled'
            specify 'the thirdPromise', -> @thirdPromise.should be 'fulfilled'

          context 'and the returned promise is rejected', ->
            before -> @returnedPromise.reject('message')

            specify 'the secondPromise', -> @secondPromise.should be 'rejected'
            specify 'the thirdPromise', -> @thirdPromise.should be 'rejected'

        context 'when the first promise is rejected', ->
          before -> @firstPromise.reject('message')

          specify 'the secondPromise', -> @secondPromise.should be 'rejected'
          specify 'the thirdPromise', -> @thirdPromise.should be 'rejected'