godoc-generate is a simple command line tool that generates default godoc comments on all exported types, functions, consts and vars in the current working directory and recursively for all subdirectories.

The godoc comments looks like this:

// %s missing godoc.

Where %s is the name of the type/func/const/var.

NOTE: The comment format can be overridden via the --format flag.

go install github.com/DimitarPetrov/godoc-generate@latest

Let's say you have a simple Multiply function without godoc:

func Multiply(a,b int) int {
	return a * b
}

It is exported, therefore it is part of the package's interface. It is ideomatic to add godoc on everything exported in your package.

If you run godoc-genenrate the code will be rewritten the following way:

// Multiply missing godoc.
func Multiply(a, b int) int {
	return a * b
}

This way you are safe to add a linter enforcing godoc and migrate all legacy code gradually.