   end
 
   test "instruments a channel action with a decorator", %{socket: socket} do
-    UsingAppsignalPhoenixChannel.handle_in("decorated", %{body: "Hello, world!"}, socket)
+    UsingAppsignalPhoenixChannel.handle_in("decorated", %{"body" => "Hello, world!"}, socket)
 
     assert [{"123", :channel}] == FakeTransaction.started_transactions
     assert "UsingAppsignalPhoenixChannel#decorated" == FakeTransaction.action

        topic: "room:lobby",
        transport: Phoenix.Transports.WebSocket
      },
      "params" => %{body: "Hello, world!"}
    } == FakeTransaction.sample_data
    assert [%Appsignal.Transaction{id: "123"}] = FakeTransaction.finished_transactions
    assert [%Appsignal.Transaction{id: "123"}] = FakeTransaction.completed_transactions

        topic: "room:lobby",
        transport: Phoenix.Transports.WebSocket
      },
      "params" => %{"body" => "Hello, world!"}
    } == FakeTransaction.sample_data
    assert [%Appsignal.Transaction{id: "123"}] = FakeTransaction.finished_transactions
    assert [%Appsignal.Transaction{id: "123"}] = FakeTransaction.completed_transactions
  end

  test "instruments a channel action with an instrumentation helper", %{socket: socket} do
    UsingAppsignalPhoenixChannel.handle_in("instrumented", %{"body" => "Hello, world!"}, socket)

    assert [{"123", :channel}] == FakeTransaction.started_transactions
    assert "UsingAppsignalPhoenixChannel#instrumented" == FakeTransaction.action
