Added no-cache to sse testing

lib/beacon_api/event_listener.ex

@@ -7,8 +7,11 @@ defmodule BeaconApi.EventPubSub do
   The idea is to have a single place to publish events, and then a method for a connection to subscribe to them.
   """
 
+  require Logger
   alias EventBus.Model.Event
+  alias LambdaEthereumConsensus.Store
   alias SSE.Chunk
+  alias Types.StateInfo
 
   @type topic() :: atom()
   @type event_data() :: any()
@@ -19,19 +22,36 @@ defmodule BeaconApi.EventPubSub do
   TODO: We might want a noop if there are no subscribers for a topic.
   """
   @spec publish(topic(), event_data()) :: :ok | {:error, atom()}
-  def publish(:finalized_checkpoint = topic, %{root: root, epoch: epoch}) do
-    data = %{root: BeaconApi.Utils.hex_encode(root), epoch: epoch}
-    chunk = %Chunk{data: [Jason.encode!(data)]}
-    event = %Event{id: UUID.uuid4(), data: chunk, topic: topic}
-
-    EventBus.notify(event)
+  def publish(:finalized_checkpoint = topic, %{root: block_root, epoch: epoch}) do
+    with %StateInfo{root: state_root} = Store.BlockStates.get_state_info(block_root) do
+      data = %{
+        block: BeaconApi.Utils.hex_encode(block_root),
+        state: BeaconApi.Utils.hex_encode(state_root),
+        epoch: epoch,
+        execution_optimistic: false
+      }
+
+      chunk = %Chunk{event: topic, data: [Jason.encode!(data)]}
+      event = %Event{id: UUID.uuid4(), data: chunk, topic: topic}
+
+      EventBus.notify(event)
+    else
+      nil ->
+        Logger.error("State not available for block", root: block_root)
+
+        {:error, :state_not_available}
+    end
   end
 
   def publish(_topic, _event_data), do: {:error, :unsupported_topic}
 
   @doc """
   Subscribe to a topic for stream events in an sse connection.
   """
-  @spec sse_subscribe(Plug.Conn.t(), topic(), event_data()) :: Plug.Conn.t()
-  def sse_subscribe(conn, topic), do: SSE.stream(conn, {[topic], %Chunk{data: []}})
+  @spec sse_subscribe(Plug.Conn.t(), topic()) :: Plug.Conn.t()
+  def sse_subscribe(conn, topic) do
+    conn
+    |> Plug.Conn.put_resp_header("cache-control", "no-cache")
+    |> SSE.stream({[topic], %Chunk{data: []}})
+  end
 end