home: vim: add formatting on save with 'null-ls'

home/vim/plugin/settings/null-ls.vim

@@ -1,4 +1,16 @@
 lua << EOF
-null_ls = require("null-ls")
+local null_ls = require("null-ls")
-null_ls.setup()
+null_ls.setup({
+    on_attach = function(client)
+        -- Format on save
+        if client.resolved_capabilities.document_formatting then
+            vim.cmd([[
+            augroup LspFormatting
+                autocmd! * <buffer>
+                autocmd BufWritePre <buffer> lua vim.lsp.buf.formatting_sync()
+            augroup END
+            ]])
+        end
+    end,
+})
 EOF