[WIP] feat: ready promise

[pkafei]

Related to #1762

[daviddias]

Please add some tests to this feature to test its behavior and update the respective documentation. Thank you!

[mikeal]

RE: documentation. Do we want to update the README to move all the examples to use this?

[alanshaw]

Please could you address the linter error?:

/home/travis/build/ipfs/js-ipfs/src/core/index.js
  190:24  error  Arrow function should not return assignment  no-return-assign

[alanshaw]

RE: documentation. Do we want to update the README to move all the examples to use this?

Yes, this should be the recommended way of obtaining a ready node.

Separately, I think we should stop advertising the callback API (both in the README and the examples) so predominantly. Instead just document that all the API methods support callbacks. I want new users to be using promises so that when #1670 lands it's easier for them to upgrade.

re: the examples here I think we should submit a separate PR to switch them all to using async await style, I'd rather not mix await ipfs.ready with callbacks.

[alanshaw]

@pkafei ping

[pkafei]

@pkafei ping

@alanshaw Saw comment and will give detailed response shortly.

[pkafei]

Yes, this should be the recommended way of obtaining a ready node.

Separately, I think we should stop advertising the callback API (both in the README and the examples) so predominantly. Instead just document that all the API methods support callbacks. I want new users to be using promises so that when #1670 lands it's easier for them to upgrade.

re: the examples here I think we should submit a separate PR to switch them all to using async await style, I'd rather not mix await ipfs.ready with callbacks.

Just want to reiterate the scope of this ticket. Here I'm implementing ready promise, and I'll update the README (docs) and add a test.

@mikeal and I plan on updating all the callbacks in the js-ipfs codebase to use async await in future tickets. I think it would be better for us to update all of the examples after we have refactored all of the callbacks to async await. Alternatively we can update the examples as we go.

[alanshaw]

@pkafei do you need some help getting this finished?

[pkafei]

@alanshaw Yes, I need help writing the test.