Project-local sources settings

[sarmong]

For lsp servers, I do the following:

• create file in a project directory
• read it inside on_init
• modify client.config.settings

However, for null-ls I cannot do this, because I do not have access to a sources settings.
How can I make project-local settings?

This was a very general question, but my specific usecase is about setting a local executable for a prettierd command. One of my project uses Yarn PnP and prettier executable is located in /path/to/project/.yarn/sdks/prettier/index.js. The easiest solution would be to use prefer_local, however there are 2 issues with it:

• it doesn't support a table (and I still want it to prefer node_modules/.bin for other projects)
• it takes a directory of the executable, not the path, so it probably won't work for index.js file if we just extend it to support tables.

[jose-elias-alvarez]

So instead of registering all of your sources at once, you could instead register sources dynamically. I'm not sure what your exact setup looks like, but assuming you're loading a Lua file, something like this might do the trick:

require("null-ls").setup({
    on_init = function()
        local has_project_local_setup = pcall(require, "project-local-setup")
        if not has_project_local_setup then
            -- general setup when project-specific setup does not exist
            require("null-ls").register({
                require("null-ls.builtins.formatting.prettier"),
            })
        end
    end,
})

-- project-local setup (lives in a separate file)
require("null-ls").register({
    require("null-ls.builtins.formatting.prettier").with({
        command = "/path/to/project/.yarn/sdks/prettier/index.js",
    }),
})

I've also seen people do this in ftplugin files. It's not a workflow I personally use, so if you can think of ways for us to improve support, I'd be happy to consider them.