Add happy-path channel tests and appease credo

apps/explorer_web/lib/explorer_web/channels/address_channel.ex

@@ -1,7 +1,13 @@
 defmodule ExplorerWeb.AddressChannel do
+  @moduledoc """
+  Establishes pub/sub channel for address page live updates.
+  """
   use ExplorerWeb, :channel
 
-  intercept ["transaction"]
+  alias ExplorerWeb.AddressTransactionView
+  alias Phoenix.View
+
+  intercept(["transaction"])
 
   def join("addresses:" <> _address_hash, _params, socket) do
     {:ok, %{}, socket}
@@ -9,8 +15,16 @@ defmodule ExplorerWeb.AddressChannel do
 
   def handle_out("transaction", %{transaction: transaction}, socket) do
     Gettext.put_locale(ExplorerWeb.Gettext, socket.assigns.locale)
-    rendered = Phoenix.View.render_to_string(ExplorerWeb.AddressTransactionView, "_transaction.html", locale: socket.assigns.locale, transaction: transaction)
-    push socket, "transaction", %{transaction: rendered}
+
+    rendered =
+      View.render_to_string(
+        AddressTransactionView,
+        "_transaction.html",
+        locale: socket.assigns.locale,
+        transaction: transaction
+      )
+
+    push(socket, "transaction", %{transaction: rendered})
     {:noreply, socket}
   end
 end

apps/explorer_web/lib/explorer_web/channels/user_socket.ex

@@ -1,7 +1,7 @@
 defmodule ExplorerWeb.UserSocket do
   use Phoenix.Socket
 
-  channel "addresses:*", ExplorerWeb.AddressChannel
+  channel("addresses:*", ExplorerWeb.AddressChannel)
 
   transport(:websocket, Phoenix.Transports.WebSocket, timeout: 45_000)
   # transport :longpoll, Phoenix.Transports.LongPoll

apps/explorer_web/test/explorer_web/channels/address_channel_test.exs

@@ -0,0 +1,20 @@
+defmodule ExplorerWeb.AddressChannelTest do
+  use ExplorerWeb.ChannelCase
+
+  describe "addresses channel tests" do
+    test "subscribed user can receive channel message" do
+      channel = "addresses"
+      @endpoint.subscribe(channel)
+
+      ExplorerWeb.Endpoint.broadcast(channel, "transaction", %{body: "test"})
+
+      receive do
+        %Phoenix.Socket.Broadcast{event: "transaction", topic: ^channel, payload: %{body: body}} ->
+          assert body == "test"
+      after
+        5_000 ->
+          assert false, "Expected message received nothing."
+      end
+    end
+  end
+end

apps/explorer_web/test/explorer_web/features/viewing_addresses_test.exs

@@ -148,13 +148,14 @@ defmodule ExplorerWeb.ViewingAddressesTest do
   end
 
   test "viewing new transactions via live update", %{addresses: addresses, session: session} do
-    session = session
-    |> AddressPage.visit_page(addresses.lincoln)
-    |> assert_has(AddressPage.balance())
+    session =
+      session
+      |> AddressPage.visit_page(addresses.lincoln)
+      |> assert_has(AddressPage.balance())
 
     transaction =
       :transaction
-      |> insert(from_address_hash: addresses.lincoln.hash)
+      |> insert(from_address: addresses.lincoln)
       |> with_block()
       |> Repo.preload([:block, :from_address, :to_address])
 

apps/explorer_web/test/support/channel_case.ex

@@ -0,0 +1,41 @@
+defmodule ExplorerWeb.ChannelCase do
+  @moduledoc """
+  This module defines the test case to be used by
+  channel tests.
+
+  Such tests rely on `Phoenix.ChannelTest` and also
+  import other functionality to make it easier
+  to build common datastructures and query the data layer.
+
+  Finally, if the test case interacts with the database,
+  it cannot be async. For this reason, every test runs
+  inside a transaction which is reset at the beginning
+  of the test unless the test case is marked as async.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      # Import conveniences for testing with channels
+      use Phoenix.ChannelTest
+
+      # The default endpoint for testing
+      @endpoint ExplorerWeb.Endpoint
+
+      import Explorer.Factory
+    end
+  end
+
+  @dialyzer {:nowarn_function, __ex_unit_setup_0: 1}
+  setup tags do
+    :ok = Ecto.Adapters.SQL.Sandbox.checkout(Explorer.Repo)
+
+    unless tags[:async] do
+      Ecto.Adapters.SQL.Sandbox.mode(Explorer.Repo, {:shared, self()})
+    end
+
+    :ok
+    # {k:ok, conn: %Plug.Conn{} |> Plug.Conn.put_private(:phoenix_endpoint, ExplorerWeb.Endpoint)}
+  end
+end