Testing our templates

In order to test our controllers with HTML responses, we will again leverage the Plug.Test module. Let’s start by creating a test module:

test/example_server_html_eex/controller_test.exs

defmodule ExampleServerHtmlEex.ControllerTest do
  use ExUnit.Case
  use Plug.Test
  describe "GET /greet" do
    test "responds with an HTML document" do
      conn = conn(:get, "/greet?greeting=Hola")
      conn = ExampleServerHtmlEex.Router.call(conn, [])
      assert conn.status == 200
      assert conn.resp_body =~ "<h1>Hola World!</h1>"
    end
  end
end

In the preceding code, we make a GET request to /greet, with the greeting query parameter set to Hola. Therefore, we expect the resulting HTML to contain &lt...