I was trying to do a simple math thing with Ruby when it occured to me that maybe it wasn't working because I wasn't using an up to date Ruby. Since I was intending to upgrade Jekyll from 3.x to 4.x, I thought "let's just do it all!!!"

There is annoying little documentation about writing a generator for Jekyll, particularly since when searching for examples, there is so much noise in form of hits for "static site generator." Two decent examples are from Ricardo Lopes and Starr Horne of Honeybadger.

Starting at the beginning, you want to be putting my_generator.rb in _plugins/ in the root directory of your Jekyll site directory.

For an absolute "Hello, World" we can do:

class Generator < Jekyll::Generator
  def generate(site)
    puts "Hello, World!"
  end
end