Test-Driven Development with Phoenix (self-published) (free)

It seems awesome. Thanks for this great free book.

I really like your book and the explanations. The first time I tried to use Wallaby, I had an error "
Wallaby can’t find phantomjs" . So I installed chromedriver and I setup Wallaby using chromedriver. It might be good to update your book to setup Wallaby with phantomjs or chromedriver. Thanks again for your book.

This is awesome! I’m learning Phoenix and I currently struggle to put TDD into practice.

I’ll definitely be reading your book. Thank you!

Thanks! I definitely need to add a little note about that at the beginning. It’ll be there when I push the next set of changes.

Fantastic! I will try to take a look soon and then share it out as a resource. Thank you!

Thank you very much for creating this!

Before parting, let’s take a moment to see what we have accomplished. We’ve written an entire application without opening our browsers. When was the last time you did that?

Very nice

The one piece of feedback I would like to share after reading through it (some sections thoroughly, some sections skimmingly) is that you do not mention property-based testing. Even if only as a footnote, mentioning it might help people to discover it as one more cool tool for their testing toolbox.

I can’t seem to get this working at all… Even with chromedriver and phantomjs installed.

I am on a mac, I installed Chromedriver and moved it to /usr/local/bin (or you need to add it to your PATH).
And in config.exs, I added

config :wallaby,
  driver: Wallaby.Experimental.Chrome,
  chromedriver: [headless: true]

Thanks, adding that to config/test.exs & chromedriver to PATH changed the error message at least!!

$ mix test
Compiling 18 files (.ex)
Generated chatter app
** (MatchError) no match of right hand side value: {:error, {:wallaby, {{:shutdown, {:failed_to_start_child, Wallaby.Experimental.Chrome, {:shutdown, {:failed_to_start_child, Wallaby.Experimental.Chrome.Chromedriver, {:eacces, [{:erlang, :open_port, [{:spawn_executable, "c:/projects/chatter/_build/test/lib/wallaby/priv/run_command.sh"}, [:binary, :stream, :use_stdio, :stderr_to_stdout, :exit_status, {:args, ["c:/tools/chromedriver/chromedriver.exe", "--log-level=OFF", "--port=57042"]}]], [file: 'erlang.erl', line: 2215]}, {Wallaby.Experimental.Chrome.Chromedriver, :init, 1, [file: 'lib/wallaby/experimental/chrome/chromedriver.ex', line: 22]}, {:gen_server, :init_it, 2, [file: 'gen_server.erl', line: 374]}, {:gen_server, 
:init_it, 6, [file: 'gen_server.erl', line: 342]}, {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}]}}}}}, {Wallaby, :start, [:normal, []]}}}}
    test/test_helper.exs:4: (file)
    (elixir 1.10.2) lib/code.ex:917: Code.require_file/2
    (elixir 1.10.2) lib/enum.ex:783: Enum."-each/2-lists^foreach/1-0-"/2
    (elixir 1.10.2) lib/enum.ex:783: Enum.each/2

What version of Wallaby are you using?

In version 0.25 and newer, Chrome stopped being experimental, so the config changes to

config :wallaby, driver: Wallaby.Chrome

If that doesn’t fix the issue, make sure you include the following in your test/test_helper.exs:

{:ok, _} = Application.ensure_all_started(:wallaby)
Application.put_env(:wallaby, :base_url, YourApplication.Endpoint.url)

That your config/test.exs file has server: true and the sql_sandbox flag:

config :chatter, Chatter.Endpoint,
  server: true

config :chatter, :sql_sandbox, true

And then use that flag in your endpoint:

  use Phoenix.Endpoint, otp_app: :chatter

  if Application.get_env(:chatter, :sql_sandbox) do
    plug Phoenix.Ecto.SQL.Sandbox
  end

Hopefully, just one of those steps is missing. Wallaby’s setup docs are pretty good. So check them out if you still have problems.