📎 Accept files for --config-path and BIOME_CONFIG_PATH

[Conaclos]

Description

See some context in #2240.

For now, the value of the CLI option -config-path and the env variable BIOME_CONFIG_PATH must be a directory that contains a Biome configuration file. This is confusing for users that expect to diretcly point to a configuration file.

To improve user experience, we should also accept a Biome configuration file as value. This change is backward compatible because a user can still specify a directory.

[ematipico]

Since this isn't clear enough, unless someone reads the original discussion, files must be biome.json or biome.jsonc. Other file names won't be accepted (even the old rome.json)

[Conaclos]

Since this isn't clear enough, unless someone reads the original discussion, files must be biome.json or biome.jsonc. Other file names won't be accepted (even the old rome.json)

Thanks for the clarification.
This makes me think a second time about that: Because we accept any filename in the extends field in a Biome configuration, this could make sense of accepting any filename as value of this option?

[ematipico]

Yeah I can see your point

[nhedger]

I also think that we should allow any file name, as it would allow users to store multiple configuration variants in the same folder under different names.

[fb55]

To add to this, the error message for a bad --config-path still references a rome.json:

% pnpm biome check --apply-unsafe --config-path=asdf/biome.json src/generated 
asdf/biome.json/rome.json internalError/fs ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Biome couldn't read the file
  
  ✖ Biome couldn't read the following file, maybe for permissions reasons or it doesn't exists: asdf/biome.json/rome.json

[Sec-ant]

Unfortunately the rome.json is a fallback file Biome will search for if it cannot find biome.json or biome.jsonc in the provided directory. But I think I can improve the error message as well.