Usage instructions error: override configs do not support "extends"

[cdfa]

Hi, the usage instructions in the README say to add an override for the extends config for MDX files, but this is not supported by eslint: eslint/eslint#8813. Just adding it to the main extends list should be fine I think.

[JounQin]

@cdfa The parser inside should only affect .mdx files, that why we need to use overrides, and overrides in npm in not extendable: eslint/eslint#12032.

So, overrides at top level is needed, and it does work on my side.

See https://github.com/JounQin/Slides/blob/master/package.json#L42-L69 for demo.

[cdfa]

Hmm, I'm not sure if I completely understand, but that seems to be an issue specifically with usage from the package.json, while the instructions specifically say to put it in the eslint config file. Anyway, adding it to the main extends list seems to work fine for me (except for the parsing issue #4)

[JounQin]

@cdfa My demo is using package.json, and I tried .eslintrc, it also works.
Did you upgrade to latest eslint? Your linked issue had been marked as resolved as far as I know.

[JounQin]

@cdfa I tried "eslint": "^5.0.0", I have the following error like your description:

Error: ESLint configuration in /Users/JounQin/Workspaces/GitHub/eslint-plugin-mdx/.eslintrc.js is invalid:
        - Unexpected top-level property "overrides[1].extends".

So I should upgrade the peerDependency eslint version to >= 6.0.0

[cdfa]

My demo is using package.json, and I tried .eslintrc, it also works.

I think eslint won't complain about it when running it for some reason, but the JSON schema for the .eslintrc simply doesn't allow it and my editors are warning me about it. Thinking about it, it may be that that schema is different than what eslint uses internally. I'll go ask if it can be updated.

[JounQin]

Just PR to update it. :)

[cdfa]

Well, I couldn't find the current version of the schema in their repo, so just gonna make an issue about it.

[JounQin]

FYI, https://github.com/SchemaStore/schemastore/blob/master/src/schemas/json/eslintrc.json

[cdfa]

Yeah that's current version on schemastore, but apparently eslint is using a different version internally and that one should be copied to schemastore.

[lolmaus]

Had this problem because eslint was an implicit dependency, and apparently an old version got installed.

Doing yarn add -D eslint (or npm i -D eslint) resolves the issue.

[JounQin]

@lolmaus IMO eslint should always be one of peerDependencies. 🤣
Glad that you've resolved your problem.