Creating test helpers

One thing I always felt was missing from Phoenix’s testing framework was the ability to simply test whether a set of routes is defined in a router. With our reflection function, it should be relatively easy to add that ability to Goldcrest.

Let’s start by defining a RouterCase module that will house the logic for the assert_route_defined? function. We want to be able to call this function in the most idiomatic way possible; therefore, we will write this function to work with a given router, set as a module attribute in the __using__/1 macro. This means a test module using RouterCase will be a singleton to one router. Let’s go ahead and define that macro:

defmodule Goldcrest.ExUnit.RouterCase do
  defmacro __using__(opts) do
    quote do
      use ExUnit.Case
      @opts unquote(opts)
      @default_router_module __MODULE__...