help/bug: LSP formatting cannot be disabled

[gegenschall]

Technically I am trying to disable formatting for a certain filetype (vue) for just some specific LSPs (vtsls, vue_ls) but I believe that's not possible with conform so I tried the next best thing which is to disable all LSP formatting. I've added the following to my config:

{
    "stevearc/conform.nvim",
    opts = {
      log_level = vim.log.levels.DEBUG,
      default_format_opts = {
        lsp_format = "fallback",
      },
      formatters_by_ft = {
        vue = { lsp_format = "never" },
      },
    },
  }

This disables all other formatters (prettier, biome) but it will still format using LSP.

I do see this in the log:

2025-09-18 15:34:08[DEBUG] Running LSP formatter on /Users/path/to/project/file.vue
2025-09-18 15:34:08[DEBUG] Running LSP formatter on /Users/path/to/project/file.vue
2025-09-18 15:34:08[DEBUG] Converting full-file LSP format to piecewise format

I'm not sure if this is actually a bug or if I'm just holding it wrong, probably the latter and in which case I'd love to know how it's actually supposed to work.

[redradrat]

Same here, with just lsp. Maybe I misunderstand this config, but in the man for conform.format I think it's quite clearly stated that the above case (lsp_format = "never" on the ft) should work.

[calops]

The lsp_format strategy in general seems to be ignored right now, whether in default options or in language-specific settings.

[itpropro]

Any update on this @stevearc or is that intended behavior?