[ljm]

Locally you’d have all the dependencies installed. In production you’d leave out development and test dependencies.

[lukeasrodgers]

Typically with rails applications, test dependencies are not used for local development (i.e. running the rails server on your local machine), they are separate groups in the Gemfile.

[ljm]

Spring and bootsnap muddy the waters. You do not have hermetic dev and test environments in Rails.