Incremental lint

[scottcorgan]

Have there been any discussions or attempts and speeding up linting a large codebase with incremental linting (only lint the files that have changed)?

Or, is this a thing already with eslint?

[sindresorhus]

ESLint recently got a cache option which can be used by Standard.

[scottcorgan]

Appreciate that.

Also, https://github.com/eslint/eslint/blob/2e17e69e879d507a55936ea7e8d92067fbdb2e6e/tests/lib/cli-engine.js#L1303

[Flet]

Why close?

[scottcorgan]

It's not an issue. More like a reference to an answer now. The solution is with eslint.

[Flet]

I guess I'm confused. I don't believe standard (or standard-engine) set the cache or the cacheFile options at all...

...so this issue could be a request to consider turning on eslint caching?

[scottcorgan]

Oh duh, you're right. Re-opening.

[rstacruz]

yes please. i like running standard with mocha-standard and mocha --watch, this would be very useful.

[nelix]

On the subject of incremental linting, an option to only lint files in git diff would be good for commit hooks, CI and perf.

[dcousens]

That would also be great for incremental repository linting: where a repository doesn't want to refactor the entire code base at once, but enforce it on all new code.
Very interested in whether someone has a solution for that.

[scottcorgan]

Is this something still on the roadmap. I saw that 2 PRs were closed on standard-engine, and I'm not sure why.

standard/standard-engine#18
standard/standard-engine#17

[feross]

Yes, this is something that I'd like to ship since it could greatly improve the time it takes to run standard. It's ~2sec for me on most projects. Would be nice to get that <1sec.

I gave this a go once, but didn't get it working reliably. @scottcorgan If you can make it work, we'll ship it!

[feross]

PR to add support to standard-engine: standard/standard-engine#125

[feross]

Merged the PR! 🎉

Running standard on a large codebase like electron/electron is now more than 2x faster on repeat runs, thanks to the ESLint cache feature!

• Before: 3.68s
• After: 1.59s

👍 👍 👍 👍 👍 👍

This will ship as part of standard v8.

[LinusU]

Awesome!! 🎉

[samhatoum]

I can't see anywhere in the docs how to enable caching this from the package.json. Is this possible?

[feross]

@samhatoum There's nothing to enable. If you're using the standard CLI then the feature is already enabled.