add cmp.get_registered_sources and CmpRegisterSource /CmpUnregisterSource autocmd.

lua/cmp/init.lua

@@ -54,13 +54,33 @@ end
 cmp.register_source = function(name, s)
   local src = source.new(name, s)
   cmp.core:register_source(src)
+  vim.api.nvim_exec_autocmds('User', {
+    pattern = 'CmpRegisterSource',
+    data = {
+      source_id = src.id
+    }
+  })
   return src.id
 end
 
 ---Unregister completion source
 ---@param id integer
 cmp.unregister_source = function(id)
-  cmp.core:unregister_source(id)
+  local s = cmp.core:unregister_source(id)
+  if s then
+    vim.api.nvim_exec_autocmds('User', {
+      pattern = 'CmpUnregisterSource',
+      data = {
+        source_id = id
+      }
+    })
+  end
+end
+
+---Get registered sources.
+---@return cmp.Source[]
+cmp.get_registered_sources = function()
+  return cmp.core:get_registered_sources()
 end
 
 ---Get current configuration.