Change Rails validation message completely

Rails always appends field name to validation messages, and when setting message: on a validation statement it gets appended to the humanized name of the field.

If you want to change the validation message completely use the locales file:

# config/locales/en.yml
en:
  activerecord:
    attributes:
      user:
        email: "E-mail address"
    errors:
      models:
        user:
          attributes:
            email:
              blank: "is required"

This was particularly useful with the ValidatesTimeliness gem which does not support a lambda.

🎉Happy 500 post to TIL 🎉