v4.0.0 much slower than v3.2.0, potentially due to linting cached webpack files 🤷

[JohnnyFun]

Bug report

I upgraded from 3.2.0 to 4.0. I'm using webpack@5.75.0 and webpack-cli@5.0.1.

Actual Behavior

When I have my webpack watch running (i.e. webpack --progress -w) and I save a js file, 4.0 takes about 19sec to do its thing. If I downgrade back to 3.2.0, it takes about one second.

Expected Behavior

I'd like it to take a lot less than 20 seconds and be closer to 1 second like it was before. Perhaps there's a configuration option that I should be making use of in either webpack or eslint-webpack-plugin?

How Do We Reproduce?

The diff between the 2 versions is pretty small, so I'm hoping it's relatively quick to track down why this would be happening. But if that's not the case, let me know if I can provide any other info that might provide insight into what might be happening.

results of npx webpack-cli info

 System:
    OS: Windows 10 10.0.22621
    CPU: (12) x64 Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz
    Memory: 12.12 GB / 31.95 GB
  Binaries:
    Node: 18.12.1 - C:\Program Files\nodejs\node.EXE
    npm: 8.8.0 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Chrome: 109.0.5414.120
    Edge: Spartan (44.22621.1105.0), Chromium (109.0.1518.52)
    Internet Explorer: 11.0.22621.1 -- You're supposed to be dead! Why won't you just die?! lol
  Packages:
    babel-loader: ^9.1.2 => 9.1.2
    copy-webpack-plugin: ^11.0.0 => 11.0.0
    eslint-webpack-plugin: ^3.2.0 => 3.2.0
    html-webpack-harddisk-plugin: ^2.0.0 => 2.0.0
    html-webpack-plugin: ^5.5.0 => 5.5.0
    svelte-loader: ^2.13.6 => 2.13.6
    terser-webpack-plugin: ^5.3.6 => 5.3.6
    webpack: ^5.75.0 => 5.75.0
    webpack-bundle-analyzer: ^4.7.0 => 4.7.0
    webpack-cli: ^5.0.1 => 5.0.1
    webpack-dev-server: ^4.11.1 => 4.11.1
    webpack-livereload-plugin: ^3.0.2 => 3.0.2

[facugaich]

Hi, you may want to post what configuration options you're using the plugin with

Have you tried passing cache: true to ESLintPlugin?

[JohnnyFun]

That was it! Sorry about that. I thought I had set that, but I had not. Thanks!

[TrevorSayre]

We also found that having threads enabled was an issue. If you have threads: true try setting to false or just remove the config line since the default is false. This has been known for a while, but thought it valuable to share in case anyone else finds that cache: true is somehow not sufficient.