feature request: option to choose formatter for the same filetype

[swann-castel]

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Describe the feature

I've added this config in formatters_by_ft = { typescript = { "biome-check", "prettierd" } } with stop_after_first = true in default_format_opts.

I would like something to trigger biome formatting only when biome.json is found, same for prettier with a .prettierrc file.

My use case is that I have several projects, some already migrated to biome, some still using prettier.

Provide background

No response

What is the significance of this feature?

strongly desired

Additional details

No response

[scallaway]

I thought there was an option to use require_cwd, but I couldn't seem to get that to work. We're currently in the middle of a ESLint+Prettier to Biome migration and being able to run Prettier in some directories and Biome in others would be really awesome.

[stevearc]

Adding require_cwd = true to the biome-check formatter should work. If it doesn't, please file a bug with a repro.

You do always have the option to define the formatters as a function

formatters_by_ft = {
  typescript = function(bufnr)
    -- some logic
    return { "biome-check" }
  end
}

You can put whatever checks and logic you want in that function.