What is an ActionDispatch::TestResponse?
ActionDispatch::TestResponse class is a subclass of
ActionDispatch::Response with a couple of convenience methods for testing. It can return its own parsed body, using the encoder that the body was encoded with.
It can also assign itself a parser, so that calls to
parsed_body don't fail if the TestResponse was manually instantiated.
It has all of a normal
Response's behavior. It's not a "light" or "fake" version of a
It used to have more behavior, back in 2009, before it was moved into the newly-introduced ActionDispatch component. ActionDispatch took over responsibility for HTTP libs and middleware, and that refactor appears to have allowed the
TestResponse to shed most of its responsibilities, except for the parsing convenience methods.