feat: add new format option: only

README.md

@@ -72,6 +72,10 @@ There are a couple special format options that LSP-format uses.
 Alternatively, you can also just not call `on_attach` for the clients you don't want to use for
 formatting.
 
+#### `only` format option
+
+`only` is a table of the only LSP servers that should format the buffer.
+
 #### `order` format option
 
 `order` is a table that determines the order formatting is requested from the LSP server.

doc/format.txt

@@ -71,6 +71,20 @@ exclude                                                   *lsp-format-exclude*
       }
 
 
+------------------------------------------------------------------------------
+only                                                      *lsp-format-only*
+
+  `only` is a table of client names to limit formatting to.
+
+  Example: >
+
+      require "lsp-format".setup {
+          go = {
+              only = { "gopls" }
+          },
+      }
+
+
 ------------------------------------------------------------------------------
 order                                                       *lsp-format-order*
 

lua/lsp-format/init.lua

@@ -63,7 +63,7 @@ local parse_value = function(key, value)
     if not value then
         return true
     end
-    if key == "order" or key == "exclude" then
+    if key == "order" or key == "exclude" or key == "only" then
         return vim.split(value, ",")
     end
     local int_value = tonumber(value)
@@ -123,13 +123,25 @@ M.format = function(options)
     end
 
     local clients = {}
-    for _, client in ipairs(get_clients { bufnr = bufnr }) do
-        if
-            client
-            and not vim.tbl_contains(format_options.exclude or {}, client.name)
-            and vim.tbl_contains(M.buffers[bufnr] or {}, client.id)
-        then
-            table.insert(clients, client)
+    if #(format_options.only or {}) > 0 then
+        for _, client in ipairs(get_clients { bufnr = bufnr }) do
+            if
+                client
+                and vim.tbl_contains(format_options.only, client.name)
+                and vim.tbl_contains(M.buffers[bufnr] or {}, client.id)
+            then
+                table.insert(clients, client)
+            end
+        end
+    else
+        for _, client in ipairs(get_clients { bufnr = bufnr }) do
+            if
+                client
+                and not vim.tbl_contains(format_options.exclude or {}, client.name)
+                and vim.tbl_contains(M.buffers[bufnr] or {}, client.id)
+            then
+                table.insert(clients, client)
+            end
         end
     end