Is v3.5.1 incompatible with v3.0.1?

[yodagg]

Version

3.5.1

Reproduction link

https://codepen.io/so-diao/pen/oNxGVvW

Steps to reproduce

https://codepen.io/so-diao/pen/oNxGVvW

What is expected?

What is actually happening?

I modified an old project package.json -> vuex: '^3.0.1' , npm i automatically downloaded the latest version (3.5.1) for me, but they are not compatible.

Why are incompatible changes occurring?

//  return jquery promise
actions: {
    fetch() {
        const Deferred = jQuery.Deferred()
        setTimeout(() =>{
            Deferred.resolve()
	}, 1500)
	return Deferred.promise()
    }
}

// v3.0.1 success
// v3.5.1 error
this.$store.dispatch('fetch').done(res =>{xxxxx})

[haoqunjiang]

Just a quick note: it's introduced in #1740.
The jQuery promise is now wrapped inside a native Promise, whose keys are not enumerable.

I think the current implementation is more accurate because the documentation has always said the dispatch method "returns a Promise that resolves all triggered action handlers". https://vuex.vuejs.org/api/#dispatch

You should not have relied on the done method, which doesn't exist in the Promise/A+ spec.

[yodagg]

It seems to be added by accident.
I see. Thank you @sodatea