I don't know if it's just because the article is 5 years old, but many of those things do exist in my editor (vs code) with the language extensions and listing

I don't know if it's just because the article is 5 years old, but many of those things do exist in my editor (vs code) with the language extensions and listing I use. Rainbow parentheses, long lines, variables not assigned to, etc etc. The colour channel is being well and truly used to close to it's maximum.