fix: don't exit Webpack on ESLint error in development

[MattIPv4]

What this PR does / why we need it:

webpack-contrib/eslint-webpack-plugin#275 fixed the default behaviour to now fail on error, which is quite annoying in development.

📦 Published PR as canary version: Canary Versions

✨ Test out this PR locally via:

npm install @grafana/[email protected]
# or 
yarn add @grafana/[email protected]

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[mckn]

Thanks for the contribution @MattIPv4. Can you elaborate a bit more on why you want to disable this for non-production mode? Just so we understand the reason behind this change.

[MattIPv4]

Sure, there are essentially two reasons behind this:

• Ensuring that the config has the same behaviour whether you're using eslint-webpack-plugin v4 or v5 (in v4 this defaulted to false, in v5 it defaults to true)
• When you're working in development with webpack in watch mode and an IDE that auto-saves, if you auto-save invalid syntax with failOnError enabled (if the IDE auto-saves as you're still typing a change for example), the entire webpack process exits which is very annoying

[jackw]

Ok, thanks for the explanation @MattIPv4 that makes sense now. 👍

[jackw]

LGTM! 🚀