Formatting "*.something" after "set filetype=yaml"

[rnprest]

I use the below autocommand to change the filetype of ´something´ to ´yaml´, which works for syntax — but not for formatting with null-ls.
Below is my autocmd and null-ls config:

vim.api.nvim_create_autocmd('BufRead', 'BufNewFile', { pattern = '*.something', command = 'set filetype=yaml' })

local null_ls = require 'null-ls'
local sources = {
    -- other sources
    null_ls.builtins.formatting.prettier,
}
null_ls.setup { sources = sources, debug = true }

Nothing happens when I try to format the test.something file, whereas the test.yaml file formats as-expected.
Both look the same syntax-wise.

Below are the only real differences in my logs (differences start at 4th line of logs):

test.something failing to work

# [DEBUG Thu Mar 17 16:47:15 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:281: Using dynamic command for [prettier], got: "prettier"
# [DEBUG Thu Mar 17 16:47:15 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:341: spawning command "prettier" at /Users/rpreston/dotfiles with args { "--stdin-filepath", "/Users/rpreston/dotfiles/neovim/.config/nvim/plugin/test.something" }
# [TRACE Thu Mar 17 16:47:15 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:224: error output: nil
# [TRACE Thu Mar 17 16:47:15 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:225: output: nil

test.yaml working

# [DEBUG Thu Mar 17 16:48:16 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:281: Using dynamic command for [prettier], got: "prettier"
# [DEBUG Thu Mar 17 16:48:16 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:341: spawning command "prettier" at /Users/rpreston/dotfiles with args { "--stdin-filepath", "/Users/rpreston/dotfiles/neovim/.config/nvim/plugin/test.yaml" }
# [TRACE Thu Mar 17 16:48:16 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:224: error output: nil
# [TRACE Thu Mar 17 16:48:16 2022] ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:225: output: %YAML 1.2
# ---
# YAML: YAML Ain't Markup Language™

# What It Is: YAML is a human-friendly data serialization
#   language for all programming languages.

For reference, the file I'm trying to format is

%YAML 1.2
---
YAML: YAML Ain't Markup Language™

What It Is:
   YAML is a human-friendly data serialization
   language for all programming languages.

which when formatted, looks like:

%YAML 1.2
---
YAML: YAML Ain't Markup Language™

What It Is: YAML is a human-friendly data serialization
  language for all programming languages.

Any clues as to how I can enable this file to be formatted with my prettier source?

[jose-elias-alvarez]

This isn't a null-ls issue–if you run Prettier with the same arguments from the command line, you'll see that it errors out because it can't infer a parser given the filename (the fact that this error is suppressed is a null-ls issue). You can manually specify the parser:

    local null_ls = require("null-ls")
    local sources = {
        null_ls.builtins.formatting.prettier.with({
            extra_args = function(params)
                return { "--parser", params.ft }
            end,
        }),
    }
    null_ls.setup({ sources = sources, debug = true })

[rnprest]

Thank you so much for the quick, in-depth response! I really appreciate it and your snippet worked perfectly out-of-the-box 😁

[jose-elias-alvarez]

Happy to help. I've also updated the logging logic a bit in bb9ec28 so that the error message will correctly show up, since I think that would have been clear from the beginning.