describe('promiseAllStepN', function(){
  describe('3 tasks, and cucurrent is 2', function(){
    let tasks;
    beforeEach(function(){
      tasks = range(3).map(x=>sinon.stub())
    })
    describe('1 is finish', function(){
      it('will kickoff the third task', function(done){
        tasks[0].returns(Promise.resolve(0))
        let task2 = tasks[2]
        tasks[1].returns(new Promise(resolve=>setTimeout(()=>{
          expect(task2.called).to.be.equal(true)
          resolve(1)
          done()
        }, 1000)))
        tasks[2].returns(Promise.resolve(2))

        return Promise.allConcurrent(2)(tasks).then(x=>console.log(x))
      })
    })
  })

  describe('10 tasks, and cucurrent is 3', function(){
    let tasks;
    beforeEach(function(){
      tasks = range(10).map(x=>sinon.stub())
    })
    describe('1st is finish but 2nd stuck', function(){
      it.only('final task will run before 2nd', function(done){
        tasks.forEach((task,index) => task.returns(Promise.resolve(index)))
        let task10 = tasks[9]
        tasks[1].returns(new Promise(resolve=>setTimeout(()=>{
          expect(task10.called).to.be.equal(true)
          resolve(1)
          done()
        }, 1000)))
        return Promise.allConcurrent(2)(tasks).then(x=>console.log(x))
      })
    })
  })

})