1380009 - Enable the ESLint no-return-await call to avoid intermediate promise creation.

Status: RESOLVED FIXED

(Toolkit :: General, enhancement)

Description

[Mark Banner (:standard8)]

Using `return await` in async functions is unnecessary since the return value is automatically wrapped in Promise.resolve(), and worst case we'd effectively be wrapping the return with a second promise.

xref: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/async_function#Rewriting_a_promise_chain_with_an_async_function

We should therefore turn on the `no-return-await` rule for ESLint to avoid this happening and fix the existing instances.

Comment 1

[Mark Banner (:standard8)]

Attachment: Bug 1380009 - Enable the ESLint no-return-await call to avoid unnecessary intermediate promise creation.

Review commit: https://reviewboard.mozilla.org/r/156324/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/156324/

Comment 2

[Florian Quèze [:florian]]

Comment on attachment 8885471 [details]
Bug 1380009 - Enable the ESLint no-return-await call to avoid unnecessary intermediate promise creation.

https://reviewboard.mozilla.org/r/156324/#review161468

::: browser/components/preferences/in-content-new/applications.js:2090
(Diff revision 1)
>     *          an integer
>     * @returns the Desktop folder if aIndex == 0,
>     *          the Downloads folder if aIndex == 1,
>     *          the folder stored in browser.download.dir
>     */
> -  async _indexToFolder(aIndex) {
> +   _indexToFolder(aIndex) {

The indent seems incorrect here.

Comment 3

[Mark Banner (:standard8)]

(In reply to Florian Quèze [:florian] [:flo] from comment #2)
> The indent seems incorrect here.

Thanks for spotting that.

Comment 4

[Mark Banner (:standard8)]

Comment on attachment 8885471 [details]
Bug 1380009 - Enable the ESLint no-return-await call to avoid unnecessary intermediate promise creation.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/156324/diff/1-2/

Comment 5

[Dave Townsend [:mossop]]

Comment on attachment 8885471 [details]
Bug 1380009 - Enable the ESLint no-return-await call to avoid unnecessary intermediate promise creation.

https://reviewboard.mozilla.org/r/156324/#review161646

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/03be1f2d0e45
Enable the ESLint no-return-await call to avoid unnecessary intermediate promise creation. r=mossop

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/03be1f2d0e45

Comment 8

[[github robot]]

Commits pushed to master at https://github.com/mozilla/normandy

https://github.com/mozilla/normandy/commit/72241cc510724b4de0edf7ab1a9a2e37e82d2a55
Bug 1380009 - Enable eslint no-return-await.

https://github.com/mozilla/normandy/commit/82ed5c43b44bd995730a5aac1e9366c735940d34
Merge pull request #890 from mythmon/backport-lints

Bug 1380009 - Enable eslint no-return-await.