Unexpected Strings must use singlequote error on jsonc/auto rule?

[JounQin]

```json
{
  "plugins": [
    "preset-lint-consistent",
    "preset-lint-recommended",
    "preset-lint-markdown-style-guide",
    "preset-prettier"
  ]
}
```

JSON in markdown, parsed by eslint-mdx with mdx/code-blocks setting enabled.

My related eslint config: https://github.com/1stG/configs/blob/master/packages/eslint-config/overrides.js#L490-L513 and prettier-config: https://github.com/1stG/configs/blob/master/packages/prettier-config/base.js

It is processed as x.md/0_x.json as virtual filename.

[JounQin]

eslint-plugin-jsonc/lib/utils/get-auto-jsonc-rules-config.ts

Line 87 in 3e2351d

const dir = dirname(filename)

related codes, virtual filenames should be considered, there is a context.getPhysicalFilename() API get the filename directly, and when a virtual filename is being used, it should be used to resolve ESLint config directly.

I'm going to work on a fix if you agree with above.

@ota-meshi

[JounQin]

And, jsonc/auto seems can not be disabled once enabled, if true, it should be documented because this behavior is definitely unsafe.

Also, it is using another ESLint CLIEngine inside on every single call, this would affect the performance implicitly, this should also be documented. This rule should be discouraged IMO.

[ota-meshi]

I haven't yet identified the cause of this issue. I'm having a hard time reproducing the problem. Can you provide a reproducible repository?

[ota-meshi]

related codes, virtual filenames should be considered, there is a context.getPhysicalFilename() API get the filename directly, and when a virtual filename is being used, it should be used to resolve ESLint config directly.

I think we probably can't use getPhysicalFilename() because we need to get the configuration of *.json 🤔

[JounQin]

https://github.com/1stG/configs/tree/repro/jsonc

Here we go.

# branch repro/jsonc

yarn && yarn eslint README.md

---

I think we probably can't use getPhysicalFilename() because we need to get the configuration of *.json 🤔

I mean if context.getPhysicalFilename() != context.getFilename(), then it is a virtual filename, we should use context.getFilename() without fallback to get its configuration, I don't know will it work as expected.

[JounQin]

And, jsonc/auto seems can not be disabled once enabled, if true, it should be documented because this behavior is definitely unsafe.

Also, it is using another ESLint CLIEngine inside on every single call, this would affect the performance implicitly, this should also be documented. This rule should be discouraged IMO.

@ota-meshi What do you think about these comments?

[ota-meshi]

CLIEngine is used only when using eslint v6 together, so I think it's okay if we drop supporting eslint v6.
What do you think?

[ota-meshi]

Also, the part where wanted to use getPhysicalFilename is the code used for eslint v6, so getPhysicalFilename does not exist yet.

[JounQin]

And, jsonc/auto seems can not be disabled once enabled

I'm not sure if it is true, when I met this bug I tried to disable rule jsonc/auto but failed.

For other ESLint versions, new eslintrc.Legacy.CascadingConfigArrayFactory() is used, right? The Legacy symbol indicates we should not rely on it? And still, it will resolve configs for every single file, right?

[ota-meshi]

And, jsonc/auto seems can not be disabled once enabled

Hmm. I can't reproduce it. If the issue remains and you can reproduce the issue, could you share the detailed steps to reproduce it?

The Legacy symbol indicates we should not rely on it?

The ESLint team plans to implement a new configuration file format. That's why, I think the current configuration format is called Legacy. However, I have not confirmed it, so it may be wrong.

[ota-meshi]

I found a document explaining it.
https://github.com/eslint/eslintrc#future-usage