til/rails/load-a-file-when-starting-rails-console.md

Load A File When Starting Rails Console

The rails console command uses irb under the hood. That means you can use any of the flags that irb supports when running rails c. One of those flags is -r which "causes irb to load the [specified] library using require."

This -r flag can come in handy if we want to load a little bit of setup code or some utility methods for our rails console session.

Let's say we have vendor/show_env.rb with this snippet of code:

puts "#{'*' * 7}  #{Rails.env.upcase}  #{'*' * 7}

And we want that to display as we open the console. We can pass the path to that file to the -r flag.

$ rails console -- -r ./vendor/show_env.rb

Notice the --. That is to indicate that we are done with console specific arguments and anything else should be passed along to irb. Without the --, the -r flag won't be recognized.

See man irb to see what other flags irb supports.