Promise.then doesn't wait

[OliverJAsh]

i.e.:

require(['bootstraps/standard'])
    .then(() => (
        new Promise(resolve => setTimeout(() => resolve(), 500))
            .then(() => console.log('foo')))
    )
    .then(() => console.log('bar'))

bar will fire before foo.

I'm happy to cast the promise using Promise.resolve, but can this be documented?

[unscriptable]

How's this, @OliverJAsh?

[Earl-Brown]

Could it be that you're not returning the promise?

Try this:

require(['bootstraps/standard'])
    .then(() => (
        return new Promise(resolve => setTimeout(() => resolve(), 500))
            .then(() => console.log('foo')))
    )
    .then(() => console.log('bar'))

In the original version, nothing is returned, so that nothing gets passed immediately into the second "then". But if you return a promise from a "then", it kind of replaces all of the following "then".

I think that's the way the spec says it should wrok.

[OliverJAsh]

@Earl-Brown I am using an arrow function which has an implicit return.

[Earl-Brown]

Ah ... that makes sense, then.

[haouarihk]

when you use arrow function like this (e)=>{//code here}
it doesn't return the data inside by default only when you use
(e)=>//code here
its the same as
(e)=>{return //code here}