refactor: async iterators

[alanshaw]

Here's a proposal for the datastore interface that uses async/await and async iterators.

😄

See ipfs/js-ipfs#1670 for context.

BTW I have no clue about flow types and have probably broken everything...I'll address that later if this PR gets a 👍

cc @ipfs/javascript-team

[jacobheun]

Just some minor feedback in the tests. Overall the API changes look good and should be straightforward to change for the other datastore's.

[hugomrdias]

this looks amazing !! love the -522 :)

On a side note i have been looking into https://github.com/sithmel/iter-tools for iterator utils.

It looks pretty good and complete with 1 minor problem the packaging.

The author uses TS and does lots of builds es5 cjs, es5 esm, es2018 etc we would use it like const map = require('iter-tools/es2018/map) in the current setup. But i opened and issue iter-tools/iter-tools#77 to hopefully improve this problem and allow for const map = require('iter-tools/map)

ps. const map = require('iter-tools/map) works now but node and browser would run totally not optimal code.

Give it a look and tell me what you think.

[alanshaw]

I was going to mention that we should probably settle on a tool like that...although I'm loving how easy those tools are to implement.

[vasco-santos]

LGTM!
-522 😁

[daviddias]

@vasco-santos it is just minus 199

That said, still great!

[pgte]

Much cleaner API, great work on the docs and tests!

[pgte]

@alanshaw please tell me when you need a release.

[achingbrain]

Can this be released?

[daviddias]

Tried but got:

[10:08:11] Test [completed]
[10:08:11] Bump Version [started]
[10:08:11] Bump Version: v0.6.0 -> v0.7.0 [title changed]
[10:08:11] Bump Version: v0.6.0 -> v0.7.0 [completed]
[10:08:11] Build [started]
[10:08:11] Clean ./dist [started]
[10:08:11] Clean ./dist [completed]
[10:08:11] Webpack Build [started]
[10:08:11] Webpack Build (94.68 KB) [title changed]
[10:08:11] Webpack Build (94.68 KB) [completed]
[10:08:11] Minify [started]
[10:08:12] Minify [failed]
[10:08:12] → Unexpected token name «await», expected punc «(»
[10:08:12] Build [failed]
[10:08:12] → Unexpected token name «await», expected punc «(»
Unexpected token name «await», expected punc «(»
SyntaxError: Unexpected token name «await», expected punc «(»
    at JS_Parse_Error.get (eval at <anonymous> (/Users/dourada/code/interface-datastore/node_modules/uglify-es/tools/node.js:21:1), <anonymous>:75:23)
    at onError (/Users/dourada/code/interface-datastore/node_modules/aegir/src/error-handler.js:11:30)
npm ERR! code ELIFECYCLE

[daviddias]

@alanshaw gave you publish perms

[achingbrain]

@daviddias thanks for trying. It needs the latest aegir to build successfully - #26 should do it.

[achingbrain]

Also, enable 2FA! 😜