[Discuss] Why did `emittedByOrder` been deprecated ?

[599316527]

Question:

1. Why did emittedByOrder been deprecated ?
2. How to get ordered events with emitted ?

wrapper.emittedByOrder() // => [{name: 'a', args: [1]}, {name: 'b', args: [3]}, {name: 'a', args: [2]}]
wrapper.emitted() // => {a: [[1], [2]], b: [[3]]}

[Justineo]

It seems that emitted cannot cover cases where we want to ensure order across different event types, eg. I want to ensure the order of the following event sequence:

emit('click')
emit('change', 1)
emit('invalid', 1)

...while emitted works if we want to check order for a same event type. Not sure why emittedByOrder is marked as deprecated.

[afontcu]

Hi! Thanks for raising this up.

Could you share a use case where asserting unordered emitted events vs. asserting them ordered yields a fragile test (or a false positive)? I understand why asserting the order seems reasonable, but I'm not entirely sure it is that critical or that it could yield to fragile tests.

Thank you! 🤗

[599316527]

Suppose there is a custom input component which will emit input event with value and invalid event with error message when user inputs. Order of input and invalid event is required to ensure the component works correctly.

Component:

<custom-input v-model="value" :minlength="3" />

Test:

cy.get('input').type('Hello');
// -----------
let events = wrapper.emittedByOrder()
expect(events[0].name).to.equal('input')
expect(events[0].args[0]).to.equal('H')
expect(events[1].name).to.equal('invalid')
expect(events[1].args[0]).to.equal('too short')
expect(events[2].name).to.equal('input')
expect(events[2].args[0]).to.equal('e')
expect(events[3].name).to.equal('invalid')
expect(events[3].args[0]).to.equal('too short')
expect(events[4].name).to.equal('input')
expect(events[4].args[0]).to.equal('l')
expect(events[5].name).to.equal('input')
expect(events[5].args[0]).to.equal('l')
expect(events[6].name).to.equal('input')
expect(events[6].args[0]).to.equal('o')

Here is the real case which I composed in my project.

https://github.com/ecomfe/veui/blob/551779bf60eed7a8cf6f871cee4b3d2d2fb2308b/packages/veui/test/unit/specs/components/Uploader.spec.js#L373-L403

[adi518]

I also wonder why. I had to resort to a hack to fix my tests 👎:

expect(Object.keys(wrapper.emitted())).toEqual(['sdk-init', 'input'])

Emitted by order helps to strict the tests, making sure the component behaves exactly as intended.