test.exs

  # set up a subscription
      ref = push_doc(socket, subscription)
      assert_reply(ref, :ok, %{subscriptionId: subscription_id})

      # run a mutation
      assert %{data: %{"signup" => %{"username" => u_name, "id" => id}}} =
               run!(mutation, variables: variables)

      expected = %{
        result: %{ data: %{ "newUser" => %{ "username" => "#{u_name}", "id" => "#{id}"}}},
        subscriptionId: subscription_id
      }

      assert_push "subscription:data", push
      assert expected == push
      
   # fail 
   
     1) test New User Subscription broadcasts new user events (MenanaweApiWeb.Schema.Subscripion.NewUserTest)
     test/lib/menanawe_api_web/subscriptions/new_user_test.exs:11
     No message matching %Phoenix.Socket.Message{event: "subscription:data", payload: push} after 100ms.
     The process mailbox is empty.
     code: assert_push "subscription:data", push
     stacktrace:
       test/lib/menanawe_api_web/subscriptions/new_user_test.exs:48: (test)

using_run.ex

# publish sub 
@spec sign_up(any(), map(), any()) :: {:ok, User.t()} | {:error, String.t()}
  def sign_up(_, %{input: params}, _) do
    with {:ok, %User{} = usr} <- Accounts.create_user(params) do

      ApiWeb.Endpoint
      |> Absinthe.Subscription.publish(usr, new_user: "*")

      {:ok, usr}
    end
  end
  
  # subscription field 
  subscription do

    field :new_user, :user do
      config fn _args, _info  ->
        {:ok, topic: "*"}
      end

      
      resolve fn root, _, _ ->
        {:ok, root}
      end
    end
  end

using_trigger.ex

# subscription 
subscription do

    field :new_user, :user do
      config fn _args, _info  ->
        {:ok, topic: "*"}
      end

      trigger [:signup], topic: fn
        %{id: id} -> [id] |> IO.inspect()
        _ -> []
      end

      resolve fn root, _, _ ->
        {:ok, root}
      end
    end
  end
  
  
  # resolver 
  # publish sub 
@spec sign_up(any(), map(), any()) :: {:ok, User.t()} | {:error, String.t()}
  def sign_up(_, %{input: params}, _) do
    with {:ok, %User{} = usr} <- Accounts.create_user(params) do

    
      {:ok, usr}
    end
  end