Create a test liveview page

lib/chronoscope_web/live/index_live.ex

@@ -0,0 +1,21 @@
+defmodule ChronoscopeWeb.IndexLive do
+  use ChronoscopeWeb, :live_view
+
+  @topic "test"
+
+  def mount(_params, _session, socket) do
+    ChronoscopeWeb.Endpoint.subscribe(@topic)
+    ChronoscopeWeb.Endpoint.broadcast_from(self(), @topic, "", %{temperature: 100})
+    {:ok, assign(socket, :temperature, 100)}
+  end
+
+  def handle_event("inc_temperature", _params, socket) do
+    updated = socket.assigns.temperature + 1
+    ChronoscopeWeb.Endpoint.broadcast_from(self(), @topic, "", %{temperature: updated})
+    {:noreply, assign(socket, :temperature, updated)}
+  end
+
+  def handle_info(%{topic: @topic, payload: state}, socket) do
+    {:noreply, assign(socket, state)}
+  end
+end

lib/chronoscope_web/live/index_live.html.heex

@@ -0,0 +1,6 @@
+<div>
+    Live!
+    <br />
+    Current temperature: <%= @temperature %>°F
+    <button phx-click="inc_temperature">+</button>
+</div>

lib/chronoscope_web/router.ex

@@ -14,6 +14,12 @@ defmodule ChronoscopeWeb.Router do
     plug :accepts, ["json"]
   end
 
+  scope "/test", ChronoscopeWeb do
+    pipe_through :browser
+
+    live "/", IndexLive
+  end
+
   scope "/", ChronoscopeWeb do
     pipe_through :browser