[BUG] eslint config basePath

[doubleaxe]

Hello.

According to eslint docs, eslint supports basePath parameter:
https://eslint.org/docs/latest/use/configure/configuration-files#specifying-base-path

But when I try to use it, config-inspector throws error:

ConfigError: Config "test": Unexpected key "basePath" found.
    at rethrowConfigError (file:///node_modules/@eslint/config-inspector/dist/cli.mjs:5115:8)
    at file:///node_modules/@eslint/config-inspector/dist/cli.mjs:6046:5
    at Array.reduce (<anonymous>)
    at ConfigArray.getConfigWithStatus (file:///node_modules/@eslint/config-inspector/dist/cli.mjs:6039:43)
    ... 2 lines matching cause stack trace ...
    at result (file:///node_modules/@eslint/config-inspector/dist/cli.mjs:59:20)
    at Object.isAppliedFilter (node_modules\@nodelib\fs.walk\out\readers\common.js:14:31)
    at #handleEntry (node_modules\@nodelib\fs.walk\out\readers\async.js:119:20)
    at node_modules\@nodelib\fs.walk\out\readers\async.js:93:38 {
  index: 4,
  [cause]: UnexpectedKeyError: Unexpected key "basePath" found.
      at ObjectSchema.validate (file:///node_modules/@eslint/config-inspector/dist/cli.mjs:4778:11)
      at file:///node_modules/@eslint/config-inspector/dist/cli.mjs:4744:9
      at Array.reduce (<anonymous>)
      at ObjectSchema.merge (file:///node_modules/@eslint/config-inspector/dist/cli.mjs:4743:18)

Here is minimal config to reproduce error:

import { defineConfig } from "eslint/config";
export default defineConfig([{
	name: "test",
	basePath: ".",
	rules: {}
}]);

[tryggvigy]

I think eslint/rewrite#223 is not making it through. I noticed v0.20 of @eslint/config-array got installed locally but it's on 0.21 now that perhaps has this change in.

[tryggvigy]

Yeah, if I force it to use v0.21 the issue goes away

[acidoxee]

I'm on ESLint v9.32.0, which ships with @eslint/config-array@^0.21.0, but I still have this issue unfortunately. I can confirm the issue goes away and my config loads perfectly if I remove basePath and only use files.

[tryggvigy]

@acidoxee but i guess config-inspector is still using the old version? Are you invoking it via npx? I'm afk now but you could install latest version in an empty repo and run:

npm/yarn/pnpm why @eslint/config-array

To check.

[acidoxee]

Thanks for your answer @tryggvigy, I wasn't using npx since I had issues with it, maybe because of Yarn being used in our project, IDK. I tried using Yarn's dlx equivalent, but no success there either. So in the end I just called the binary directly with yarn eslint-config-inspector.

In my repo, yarn why @eslint/config-inspector yields the following result:

└─ my-project@workspace:.
   └─ @eslint/config-inspector@npm:1.2.0 [0b2ab] (via npm:^1.2.0 [0b2ab])

While yarn why @eslint/config-array yields:

├─ eslint@npm:9.34.0
│  └─ @eslint/config-array@npm:0.21.0 (via npm:^0.21.0)
│
└─ eslint@npm:9.34.0 [0b2ab]
   └─ @eslint/config-array@npm:0.21.0 (via npm:^0.21.0)

So I believe it's already using the latest version of @eslint/config-array. I've updated @eslint/config-inspector to v1.3.0 right now, and while @eslint/config-array is still using v0.21.0, the inspector does seem to work this time (at least it doesn't crash at startup!), so I'm guessing this is solved now? 🙏