change rails environment in the mid of testing

Question

How to change the environment variable of rails in testing

Answer 1

Sometimes returning a different environment variable can be a headache (required production environment variables, warning messages, etc).

Depending on your case, as an alternate you may be able to simply return the value you need for your test to think it's in another environment. Such as if you wanted Rails to believe it is in production for code that checks Rails.env.production? you could do something like this:

it "does something specific when in production" do 
  allow(Rails.env).to receive(:production?).and_return(true)
  ##other assertions
end

You could do the same for other environments, such as :development?, :staging?, etc. If you don't need the full capacity of returning a full environment, this could be another option.