fix(treesitter): do not error on empty filetype

Ignore instead

2 files changed, 3 insertions, 16 deletions

diff --git a/runtime/lua/vim/treesitter/language.lua b/runtime/lua/vim/treesitter/language.lua
index 5f34d9cd56..47375fd5e6 100644
--- a/runtime/lua/vim/treesitter/language.lua
+++ b/runtime/lua/vim/treesitter/language.lua
@@ -60,16 +60,6 @@ function M.add(lang, opts)
     filetype = { filetype, { 'string', 'table' }, true },
   })
 
-  if filetype == '' then
-    error(string.format("'%s' is not a valid filetype", filetype))
-  elseif type(filetype) == 'table' then
-    for _, f in ipairs(filetype) do
-      if f == '' then
-        error(string.format("'%s' is not a valid filetype", filetype))
-      end
-    end
-  end
-
   M.register(lang, filetype or lang)
 
   if vim._ts_has_language(lang) then
@@ -109,7 +99,9 @@ function M.register(lang, filetype)
   end
 
   for _, f in ipairs(filetypes) do
-    ft_to_lang[f] = lang
+    if f ~= '' then
+      ft_to_lang[f] = lang
+    end
   end
 end
 
diff --git a/test/functional/treesitter/language_spec.lua b/test/functional/treesitter/language_spec.lua
index 747aea54b7..48e7b4b018 100644
--- a/test/functional/treesitter/language_spec.lua
+++ b/test/functional/treesitter/language_spec.lua
@@ -36,11 +36,6 @@ describe('treesitter language API', function()
       pcall_err(exec_lua, 'vim.treesitter.add("/foo/")'))
   end)
 
-  it('shows error for invalid filetype', function()
-    eq('.../language.lua:0: \'\' is not a valid filetype',
-      pcall_err(exec_lua, [[vim.treesitter.add('foo', { filetype = '' })]]))
-  end)
-
   it('inspects language', function()
     local keys, fields, symbols = unpack(exec_lua([[
       local lang = vim.treesitter.inspect_language('c')