Run treefmt on nvim buffer save

home-manager/neovim/lspconfig.lua

@@ -45,14 +45,21 @@ require("lspconfig").terraformls.setup({
 	capabilities = capabilities,
 })
 
--- require'lspconfig'.efm.setup {
---     on_attach = require("lsp-format").on_attach,
---     init_options = {documentFormatting = true},
---     settings = {
---         languages = {
---             lua = {{formatCommand = "lua-format -i", formatStdin = true}},
---             nix = {{formatCommand = "nixfmt", formatStdin = true}}
---         }
---     },
---     filetypes = {"lua", "nix"}
--- }
+local function has_treefmt()
+    local git_root = vim.fn.systemlist("git rev-parse --show-toplevel")[1]
+    if vim.v.shell_error ~= 0 then
+        return false
+    end
+    local treefmt_path = git_root .. "/treefmt.nix"
+    return vim.fn.filereadable(treefmt_path) == 1
+end
+
+vim.api.nvim_create_autocmd("BufWritePost", {
+    pattern = "*",
+    callback = function()
+        if has_treefmt() then
+		vim.cmd("silent !treefmt > /dev/null 2>&1")
+        end
+    end,
+    group = vim.api.nvim_create_augroup("TreefmtAutoformat", { clear = true }),
+})