feat(prettier): add options for configuring prettier parser based o…

…n filetype and extension (#241)

lua/conform/formatters/prettier.lua

@@ -1,15 +1,62 @@
 local util = require("conform.util")
+
+--- Helper function to parse options to into a parser if available
+---@param self conform.JobFormatterConfig
+---@param ctx conform.Context|conform.RangeContext
+---@return string[]|nil args the arguments for setting a `prettier` parser if they exist in the options, nil otherwise
+local function eval_parser(self, ctx)
+  local ft = vim.bo[ctx.buf].filetype
+  local ext = vim.fn.fnamemodify(ctx.filename, ":e")
+  local options = self.options
+  local parser = options
+    and (
+      (options.ft_parsers and options.ft_parsers[ft])
+      or (options.ext_parsers and options.ext_parsers[ext])
+    )
+  if parser then
+    return { "--parser", parser }
+  end
+end
+
 ---@type conform.FileFormatterConfig
 return {
   meta = {
     url = "https://github.com/prettier/prettier",
     description = [[Prettier is an opinionated code formatter. It enforces a consistent style by parsing your code and re-printing it with its own rules that take the maximum line length into account, wrapping code when necessary.]],
   },
+  options = {
+    -- add parsers for different filetypes
+    ft_parsers = {
+      --     javascript = "babel",
+      --     javascriptreact = "babel",
+      --     typescript = "typescript",
+      --     typescriptreact = "typescript",
+      --     vue = "vue",
+      --     css = "css",
+      --     scss = "scss",
+      --     less = "less",
+      --     html = "html",
+      --     json = "json",
+      --     jsonc = "json",
+      --     yaml = "yaml",
+      --     markdown = "markdown",
+      --     ["markdown.mdx"] = "mdx",
+      --     graphql = "graphql",
+      --     handlebars = "glimmer",
+    },
+    -- add parsers for different extensions
+    ext_parsers = {
+      -- qmd = "markdown",
+    },
+  },
   command = util.from_node_modules("prettier"),
-  args = { "--stdin-filepath", "$FILENAME" },
+  args = function(self, ctx)
+    return eval_parser(self, ctx) or { "--stdin-filepath", "$FILENAME" }
+  end,
   range_args = function(self, ctx)
     local start_offset, end_offset = util.get_offsets_from_range(ctx.buf, ctx.range)
-    return { "$FILENAME", "--range-start=" .. start_offset, "--range-end=" .. end_offset }
+    local args = eval_parser(self, ctx) or { "$FILENAME" }
+    return vim.list_extend(args, { "--range-start=" .. start_offset, "--range-end=" .. end_offset })
   end,
   cwd = util.root_file({
     -- https://prettier.io/docs/en/configuration.html