There are many techniques. You're most likely to come across things like declarative DSL:s and macros, then there are things like JAXB and similar tooling that generates code from data schemas, and some people script around data sources to glue boilerplate and so on.

Arguably snippet collections belong to this genre.

For example `rails generate ...` built into the Rails CLI.

See, for example, this blog post from 2014: https://go.dev/blog/generate

The following comment in the blog post

    //go:generate stringer -type=Pill

generates a .._string.go file which contains a '.String()' method.

I would find it very reasonable to commit that with 'Co-Authored-By: stringer v0.1.0' or such.

Or 'sed s/a/b/g' and 'Co-Authored-By: sed'

Holy shit I’m old.