The Complete Computing Environment

Ruby and Rails in Emacs


Right now this is disabled: in the future my rails dev projects should "just" ship a shell.nix for Nix.

I use Ruby on Rails for prototyping web applications, it's quick and useful and it's easy to not shoot yourself in the foot with it for personal projects. A lot of this is about setting up the Ruby Version Manager, node.js and the YARN package manager for Node.js's development. I think it's kind of funny the way people respond to Rails these days, but it continues to be an incredible tool for rapid prototyping and exploration of simple data driven applications. Of course life is hard when you're hitting the limits of MRI, but if you have a thing that can fit in a sqlite database on your laptop or a heroku hobby dyno, you can't really complain.

I use Robe for ruby development, rather than the LSP. I additionally install a pry frontend for the Emacs debugger realgud, even if I've never used it, as well as projectile-rails and yari, a viewer of Ruby ri documentation.

(use-package realgud-pry)
(use-package yari
  (evil-set-initial-state 'yari-mode 'motion)
  :bind (:map evil-leader--default-map
              ("y" . yari)))
(use-package robe
  :after company
  (push 'company-robe company-backends)
  (ruby-mode . robe-mode)
  (ruby-mode . ruby-electric-mode))
(use-package projectile-rails
  (ruby-mode . projectile-rails-on)
  (web-mode  . projectile-rails-on))

(add-to-list 'auto-mode-alist '("\\.erb\\'" . web-mode))
(provide 'cce/ruby)

I use a tool called Bundix which generates a Nix derivation of a Gemfile.lock which can be used in nix-shell.

{ pkgs, ... }:

  home.packages = [ pkgs.bundix ];

Here's a default.nix to crib on new projects; shell in to them, run bundix -m, then drop in:

with (import <nixpkgs> {});
  gems = bundlerEnv {
    name = "drip-demo";
    inherit ruby;
    gemdir = ./.;
in stdenv.mkDerivation {
  name = "drip-demo";
  buildInputs = [