jasmine done callback behaviour

jasmine-done-callback-behaviour.js

describe('experiments with done', ()=>{

	describe('- correct usage -', ()=>{

		it('should fail because of async expect failure, and failure is assigned to correct spec', (done)=>{
			new Promise(function(res, rej){
				setTimeout(res, 1000)
			}).then(()=>{
				expect(1).toEqual(11)
			}).catch().then(done)
		})

		it('should wait for async done call', (done)=>{
			new Promise(function(res, rej){
				setTimeout(res, 1000)
			}).then(()=>{
				expect(4).toEqual(4)
				done()
			})
		})

		it('should wait for async done call, but fails meanwhile', (done)=>{
			new Promise(function(res, rej){
				setTimeout(res, 1000)
			}).then(()=>{
				expect(4).toEqual(44)
				done()
			})
		})

		it('should wait for async done call, which is at the end of the promise chain', (done)=>{
			new Promise(function(res, rej){
				setTimeout(res, 1000)
			}).then(()=>{
				expect(1).toEqual(1)
			}).catch().then(done)
		})
	})

	describe('- incorrect usage -', ()=>{

		it('should fail because of async expect failure, but wont since done not used', ()=>{
			new Promise(function(res, rej){
				// this expect throws an error, which jasmine is handling while already processing a succeeding spec.
				// hence the error will be assigned to that wrong spec.
				setTimeout(res, 1000)
			}).then(()=>{
				expect(2).toEqual(22)
			})
		})

		it('should fail with failed expect from previous spec', (done)=>{
			// most likely the failed expectation from previous spec will be detected and reported here.
			new Promise(function(res, rej){
				setTimeout(res, 1000)
			}).then(done)
		})
	})
})