1456078 - Investigate ESLint 5.0.x's compatibility

Status: RESOLVED FIXED

(Developer Infrastructure :: Lint and Formatting, enhancement, P2)

Description

[Mark Banner (:standard8)]

ESLint 5.0.0-alpha.1 has been released:

https://eslint.org/blog/2018/04/eslint-v5.0.0-alpha.1-released

There's a few breaking changes listed

https://eslint.org/docs/5.0.0/user-guide/migrating-to-5.0.0

We should check what needs fixing, and if there's any issues we pick up in ESLint 5 itself.

Comment 1

[Mark Banner (:standard8)]

I've just experimented with upgrading to the alpha, and surprisingly, only one issue was found:

browser/base/content/tabbrowser.js
  590:27  error  'CSSAnimation' is not defined.  no-undef (eslint)

This is due to the removal of some browser/node globals that are apparently deprecated (we still seem to support it though).

The only other thing I've spotted is that the minimum node version is now 6.14.0, we're on 6.9.1, although 6.9.1 isn't broken for ESLint (and I guess it is unlikely), I think it makes it a good time to upgrade the requirement to 8.9.x as per the recent node thread.

I'll probably do that in a separate bug though, before this hits completely. First I'll send an intent to require.

Comment 2

[Mark Banner (:standard8)]

I've just looked at 5.0.0-alpha.3, I've spotted a regression in how ESLint handles valid-jsdoc & return from async functions which I've filed as:

https://github.com/eslint/eslint/issues/10386

There's also an issue with a deprecation warning that appears in the json output as non-json, so I filed that as well:

https://github.com/eslint/eslint/issues/10387

though I'll also file a bug for getting the one remaining use of `experimentalObjectRestSpread` replaced.

Also, alpha 3 has changed no-self-assign's default to look at properties as well. That's picked up a few more issues, that I'll file bugs for.

Comment 3

[Mark Banner (:standard8)]

Attachment: Bug 1456078 - Enable eslint-plugin-mozilla's parsing of HTML files to understand script tags with type="module".

MozReview-Commit-ID: LpmqJI5s4aX

Comment 4

[Mark Banner (:standard8)]

Attachment: Bug 1456078 - Upgrade ESLint to version 5.3.0, and eslint-plugin-html to 4.0.5.

MozReview-Commit-ID: 7yvvXKxYodA

Comment 5

[Mark Banner (:standard8)]

Try push: https://treeherder.mozilla.org/#/jobs?repo=try&revision=51b8c20550651b88aa4006b005e6734b5ed27369

Comment 6

[Phabricator Automation]

Comment on attachment 8998130 [details]
Bug 1456078 - Upgrade ESLint to version 5.3.0, and eslint-plugin-html to 4.0.5.

Dave Townsend [:mossop] has approved the revision.

https://phabricator.services.mozilla.com/D2834

Comment 7

[Phabricator Automation]

Comment on attachment 8998125 [details]
Bug 1456078 - Enable eslint-plugin-mozilla's parsing of HTML files to understand script tags with type="module".

Dave Townsend [:mossop] has approved the revision.

https://phabricator.services.mozilla.com/D2833

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d7e4ce95a34e
Enable eslint-plugin-mozilla's parsing of HTML files to understand script tags with type="module". r=mossop

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cbd1cebd5af9
Upgrade ESLint to version 5.3.0, and eslint-plugin-html to 4.0.5. r=mossop

Comment 10

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/d7e4ce95a34e
https://hg.mozilla.org/mozilla-central/rev/cbd1cebd5af9

Comment 11

[Dave Townsend [:mossop]]

Note that this has broken ESLint in VS Code which uses an older node version than we target. I have created a patch for VS Code's ESLint plugin to correct the problem and am waiting for it to be merged: https://github.com/Microsoft/vscode-eslint/issues/345