We'll need to fix up our tests very quickly as well. For the most part, we can just reuse the code from the poll channel tests. We'll start off with a standard channel test skeleton. Create test/vocial_web/channels/chat_channel_test.exs and we'll start it off simply enough:

defmodule VocialWeb.ChatChannelTest do
  use VocialWeb.ChannelCase

  alias VocialWeb.ChatChannel
end

Next, we'll add a setup block. We'll start off by creating a user and a poll to give us our baseline:

setup do
    {:ok, user} = Vocial.Accounts.create_user(%{
      username: "test",
      email: "[email protected]",
      password: "test",
      password_confirmation: "test"
    })
    {:ok, poll} = Vocial.Votes.create_poll_with_options(
      %{ "title" => "My New Test Poll", "user_id" => user.id },
      ["One", "Two", "Three"]
    )

Then we'll create a mock socket that will join the chat lobby and the chat for the created poll:

    socket = socket("user_id", %{user_id: user.id})
    {:ok, _, poll_socket} = subscribe_and_join(socket, ChatChannel, "chat:#{poll.id}", %{})
    {:ok, _, lobby_socket} = subscribe_and_join(socket, ChatChannel, "chat:lobby", %{})

Finally, we return out the information that we've created as a part of this setup block:

  {:ok, poll_socket: poll_socket, lobby_socket: lobby_socket, user: user, poll: poll}
end

Next, we'll write a test that makes sure we get a reply from the socket and a broadcast from the socket that matches the author/message format we specified in the channel itself:

  test "new_message replies with status ok for chat:poll_id", %{poll_socket: socket} do
    ref = push socket, "new_message", %{"author" => "test", "message" => "Hello World"}
    assert_reply ref, :ok, %{author: author, message: message}
    assert author == "test"
    assert message == "Hello World"

    assert_broadcast "new_message", %{author: author, message: message}
    assert author == "test"
    assert message == "Hello World"
  end

Finally, we duplicate the test for the chat lobbies as well:

  test "new_message replies with status ok for chat:lobby", %{lobby_socket: socket} do
    ref = push socket, "new_message", %{"author" => "test", "message" => "Hello World"}
    assert_reply ref, :ok, %{author: author, message: message}
    assert author == "test"
    assert message == "Hello World"

    assert_broadcast "new_message", %{author: author, message: message}
    assert author == "test"
    assert message == "Hello World"
  end

And that's it! If we run our tests for the chat channel now, we should see nice green tests:

mix test test/vocial_web/channels/chat_channel_test.exs
..

Finished in 1.2 seconds
2 tests, 0 failures

Randomized with seed 933948