refactor: copilot attach conditions

Author: MunifTanjim

lua/copilot/client.lua

@@ -9,55 +9,10 @@ local register_autocmd = function ()
   })
 end
 
-local default_filetypes = {
-  yaml = false,
-  markdown = false,
-  help = false,
-  gitcommit = false,
-  gitrebase = false,
-  hgcommit = false,
-  svn = false,
-  cvs = false,
-  ["."] = false,
-}
-
-local function is_ft_disabled(ft)
-  --- for backward compatibility
-  if M.params.ft_disable and vim.tbl_contains(M.params.ft_disable, ft) then
-    return true
-  end
-
-  if M.params.filetypes[ft] ~= nil then
-    return not M.params.filetypes[ft]
-  end
-
-  local short_ft = string.gsub(ft, "%..*", "")
-
-  if M.params.filetypes[short_ft] ~= nil then
-    return not M.params.filetypes[short_ft]
-  end
-
-  if M.params.filetypes['*'] ~= nil then
-    return not M.params.filetypes['*']
-  end
-
-  if default_filetypes[short_ft] ~= nil then
-    return not default_filetypes[short_ft]
-  end
-
-  return false
-end
-
 ---@param force? boolean
 function M.buf_attach(client, force)
-  if not force then
-    if is_ft_disabled(vim.bo.filetype) then
-      return
-    end
-
-    if not vim.bo.buflisted or not vim.bo.buftype == "" then
-      return
-    end
+  if not force and not util.should_attach(M.params.filetypes) then
+    return
   end
 
   client = client or util.get_copilot_client()
@@ -106,6 +61,13 @@ end
 
 M.start = function(params)
   M.params = params
+  --- for backward compatibility
+  if M.params.ft_disable then
+    for _, disabled_ft in ipairs(M.params.ft_disable) do
+      M.params.filetypes[disabled_ft] = false
+    end
+  end
+
   vim.lsp.start_client(M.merge_server_opts(params))
 end
 

lua/copilot/util.lua

@@ -57,6 +57,65 @@ M.get_copilot_client = function()
   end
 end
 
+local internal_filetypes = {
+  yaml = false,
+  markdown = false,
+  help = false,
+  gitcommit = false,
+  gitrebase = false,
+  hgcommit = false,
+  svn = false,
+  cvs = false,
+  ["."] = false,
+}
+
+---@param ft string
+---@param filetypes table<string, boolean>
+---@return boolean ft_disabled
+---@return string? ft_disabled_reason
+local function is_ft_disabled(ft, filetypes)
+  if filetypes[ft] ~= nil then
+    return not filetypes[ft], string.format("'filetype' %s rejected by config filetypes[%s]", ft, ft)
+  end
+
+  local short_ft = string.gsub(ft, "%..*", "")
+
+  if filetypes[short_ft] ~= nil then
+    return not filetypes[short_ft], string.format("'filetype' %s rejected by config filetypes[%s]", ft, short_ft)
+  end
+
+  if filetypes["*"] ~= nil then
+    return not filetypes["*"], string.format("'filetype' %s rejected by config filetypes[%s]", ft, "*")
+  end
+
+  if internal_filetypes[short_ft] ~= nil then
+    return not internal_filetypes[short_ft], string.format("'filetype' %s rejected by internal_filetypes[%s]", ft, short_ft)
+  end
+
+  return false
+end
+
+---@param filetypes table<string, boolean>
+---@return boolean should_attach
+---@return string? no_attach_reason
+function M.should_attach(filetypes)
+  local ft_disabled, ft_disabled_reason = is_ft_disabled(vim.bo.filetype, filetypes)
+
+  if ft_disabled then
+    return not ft_disabled, ft_disabled_reason
+  end
+
+  if not vim.bo.buflisted then
+    return false, "buffer not 'buflisted'"
+  end
+
+  if not vim.bo.buftype == "" then
+    return false, "buffer 'buftype' is " .. vim.bo.buftype
+  end
+
+  return true
+end
+
 function M.is_attached(client)
   client = client or M.get_copilot_client()
   return client and vim.lsp.buf_is_attached(0, client.id) or false