SubscriptionsTransportWS.SocketTest.assert_receive_subscription

You're seeing just the macro assert_receive_subscription, go back to SubscriptionsTransportWS.SocketTest module for more information.
Link to this macro

assert_receive_subscription(payload, timeout \\ Application.fetch_env!(:ex_unit, :assert_receive_timeout))

View Source (macro)

Helper function to receive subscription data over the socket

Example

push_doc(socket, "mutation submitPost($title: String, $body: String){
      submitPost(title: $title, body: $body){
        id
        body
        title

      }
    }", variables: %{title: "test title", body: "test body"})

assert_receive_subscription %{
  "data" => %{
    "postAdded" => %{"body" => "test body", "id" => "1", "title" => "test title"}
  }
}