   end
 
   test "app revision from application env" do
-    System.delete_env("APP_REVISION")
     Application.put_env(:appsignal, :config,
       push_api_key: "-test",
       revision: "b5f2b9")

  end

  test "app config from application env gets put in system env" do
    System.delete_env("APPSIGNAL_ACTIVE")
    System.delete_env("APPSIGNAL_ENVIRONMENT")
    System.delete_env("APPSIGNAL_PUSH_API_KEY")
    System.delete_env("APPSIGNAL_APP_NAME")
    System.delete_env("APPSIGNAL_ENABLE_HOST_METRICS")
    System.delete_env("APP_REVISION")

    Application.put_env(:appsignal, :config,
      active: true,


  alias Appsignal.Config

  setup do
    Application.delete_env(:appsignal, :config)

    System.delete_env("APPSIGNAL_ACTIVE")
    System.delete_env("APPSIGNAL_ENVIRONMENT")
    System.delete_env("APPSIGNAL_PUSH_API_KEY")
    System.delete_env("APPSIGNAL_APP_NAME")
    System.delete_env("APPSIGNAL_ENABLE_HOST_METRICS")
    System.delete_env("APP_REVISION")
  end

  test "unconfigured" do
    System.put_env("APPSIGNAL_PUSH_API_KEY", "")
    assert {:error, :invalid_config} = Config.initialize()
  end

