Testing the controller

Now that we have a way to define our controllers, it’s time to see how we can test them. Of course, we could simply test the entire HTTP request the same way we tested our HTTP servers in the previous chapters. However, there’s a better and simpler way to test the controller responses.

Since our routers and our controllers are plugs, we can test them using the Plug.Test module. The Plug.Test module contains a collection of helper functions that are designed to help us test plugs better.

Here is how we can use Plug.Test to test our controller’s /greet action:

test/goldcrest/support/example_controller_test.exs

defmodule Goldcrest.ExampleControllerTest do
  use ExUnit.Case
  use Plug.Test
  describe "GET /greet" do
    test "responds with 200 status" do
      conn = conn(:get, "/greet")
      ...