Perfomance degradation in import plugin after eslint 6

Tell us about your environment

• ESLint Version: tested on latest versions of 5,6,7
• Node Version: 12.18.3
• npm Version: 6.14.6 What parser (default, @babel/eslint-parser, @typescript-eslint/parser, etc.) are you using? default

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

Updated eslint from version 5 to 6 and 7.

What did you expect to happen?

Expected no performance degradation, before update timing looked like this:

What actually happened? Please include the actual, raw output from ESLint. Actually after update to 6 or 7 version I got insane degradation in eslint import plugin. Nothing else besides eslint version was changed. Also tried installing latest version of import plugin but go the same picture. Seems like there is some important change in Eslint 6.0. I looked through release notes but couldn’t find the problem yet.

Are you willing to submit a pull request to fix this bug? No, still not sure what in Elint caused this problem. Help wanted.

[nzakas]

There’s likely not an issue with the import plugin at all. Note that the rule order is different before and after upgrading. It’s not the rules or the plugin that is the problem, it’s all the bootstrapping ESLint is doing before even running the first rule.

Config is pretty complicated, which is why we are replacing it with a simpler system. Unfortunately, I don’t think we can boost the performance of configs right now without jeopardizing current work. I’m pushing forward on #13481 as fast as I can.

[nzakas]

FYI there is an issue open for separation of bootstrap costs from rule performance: https://github.com/eslint/eslint/issues/13695