fork-ts-checker-webpack-plugin: ESLint checking from the 1st compilation blocks 2nd webpack compilation (tapAfterCompileToAddDependencies)

Current behavior

1. During the initial compilation, fork-ts-checker starts doing its thing, and one of these things is getDependencies.
2. Dependencies resolution will be written to dependenciesPromise
3. Next webpack compilation will stumble upon tapAfterCompileToAddDependencies hook.
4. If dependencies weren’t resolved yet, this compilation will be blocked until fork-ts-checker finishes its job.

• My first initial compilation takes ~22 seconds.
• Initial TS+ESLint checks take something like 2 minutes.
• Without this plugin an HMR recompilation takes 1-2 seconds.
• Issue: With the plugin, an HMR recompilation will have to wait for dependenciesPromise to resolve which means I can’t use the app for the next 2 minutes while plugin is doing all the checks.

Illustration of the issue at hand, hope it’s not too messy (I added a couple of logs to show how much time tapAfterCompileToAddDependencies takes).

Note: I can disable ESLint and this doesn’t happen. getDependencies takes so long for ESLint specifically.

Expected behavior

Not sure how this should be fixed, but maybe this can work?

• Don’t tap into afterCompile hook.
• Wait until getDependencies resolves and only after that tap some hook and add resolved dependencies into next webpack compilation?

I couldn’t really make this work locally for me, but if you can point me to the right solution, I can make a PR.

Steps to reproduce the issue

• Have a project big enough for ESLint’s getDependencies to take considerable time.
• Compile with webpack and immediately do an HMR recompilation - easiest use-case is when lazyCompilation is enabled.
• Notice how 2nd webpack compilation will only finish when fork-ts-checker is finished.

Issue reproduction repository

I can try to create one if description above isn’t enough.

Environment

• fork-ts-checker-webpack-plugin: 6.2.6
• typescript: 4.1.2 (irrelevant I think)
• eslint: 7.8.1
• webpack: 5.35.0
• os: win10