1436389 - Upgrade ESLint to the latest version (4.17.0)

Status: RESOLVED FIXED

(Developer Infrastructure :: Lint and Formatting, enhancement, P1)

Description

[Mark Banner (:standard8)]

We should upgrade ESLint to the latest version. There's various fixes and improvements.

Of note:

- v4.15 added support for messageIds, this simplifies rules & tests https://eslint.org/blog/2018/01/eslint-v4.15.0-released
- There's improvements in complexity calculations, though unfortunately a lot of our complexity values have increased.

There's also a change for how eslint-env is evaluated which breaks our xbl files. Seeing as we're working on removing these, the easiest thing is to switch to glob-based config and specify it in the root .eslintrc.js for now.

Comment 1

[Mark Banner (:standard8)]

Attachment: Bug 1436389 - Upgrade ESLint to version 4.17.0.

Review commit: https://reviewboard.mozilla.org/r/218528/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/218528/

Comment 2

[Mark Banner (:standard8)]

Attachment: Bug 1436389 - Switch xbl related files to a different method for determining their environment.

Review commit: https://reviewboard.mozilla.org/r/218530/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/218530/

Comment 3

[Mark Banner (:standard8)]

Attachment: Bug 1436389 - Update complexity rules to adapt for the algorithm in the new ESLint.

Review commit: https://reviewboard.mozilla.org/r/218532/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/218532/

Comment 4

[Mark Banner (:standard8)]

Attachment: Bug 1436389 - Fix space-unary-ops issues picked up by the new version of ESLint.

Review commit: https://reviewboard.mozilla.org/r/218534/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/218534/

Comment 5

[Dave Townsend [:mossop]]

Comment on attachment 8949130 [details]
Bug 1436389 - Upgrade ESLint to version 4.17.0.

https://reviewboard.mozilla.org/r/218528/#review224334

Comment 6

[Dave Townsend [:mossop]]

Comment on attachment 8949131 [details]
Bug 1436389 - Switch xbl related files to a different method for determining their environment.

https://reviewboard.mozilla.org/r/218530/#review224336

Comment 7

[Dave Townsend [:mossop]]

Comment on attachment 8949132 [details]
Bug 1436389 - Update complexity rules to adapt for the algorithm in the new ESLint.

https://reviewboard.mozilla.org/r/218532/#review224338

Is complexity something that it is really useful to lint? All these numbers just seem somewhat arbitrary and I don't know that we're gaining much from them.

Comment 8

[Dave Townsend [:mossop]]

Comment on attachment 8949133 [details]
Bug 1436389 - Fix space-unary-ops issues picked up by the new version of ESLint.

https://reviewboard.mozilla.org/r/218534/#review224340

Comment 9

[Mark Banner (:standard8)]

(In reply to Dave Townsend [:mossop] from comment #7)
> Is complexity something that it is really useful to lint? All these numbers
> just seem somewhat arbitrary and I don't know that we're gaining much from
> them.

We might want to review this at some stage, I think we either need to be actively working to reduce the complexity of a lot of these function (and get people on board), or abandon it for the time being.

I have to say, some of the functions I've seen in relation to this do look excessively complex and I suspect would be hard to understand for people not familiar with the code, and very hard to test.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/098f79553745
Upgrade ESLint to version 4.17.0. r=mossop
https://hg.mozilla.org/integration/autoland/rev/584d21820d82
Switch xbl related files to a different method for determining their environment. r=mossop
https://hg.mozilla.org/integration/autoland/rev/89b11edb7dd1
Update complexity rules to adapt for the algorithm in the new ESLint. r=mossop
https://hg.mozilla.org/integration/autoland/rev/2ebcb42faee2
Fix space-unary-ops issues picked up by the new version of ESLint. r=mossop

Comment 11

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/098f79553745
https://hg.mozilla.org/mozilla-central/rev/584d21820d82
https://hg.mozilla.org/mozilla-central/rev/89b11edb7dd1
https://hg.mozilla.org/mozilla-central/rev/2ebcb42faee2