Unexpected HTTP 500 response

[Sviatoslav Flud]

Hi.
I put my plug on post request in router:

post("/upload", Project.Plugs.UploadHooks, :call)

There is a small part of plug:

  ## UploadHooks module
  def call(conn, _) do
    conn
    |> get_req_header("hook-name")
    |> trigger_hook(conn, conn.params)
  end

  ## PRE-CREATE hook clauses
  ## This event will be triggered before an upload is created.
  ## At this stage, verification and authorization of upload metadata is performed.
  defp trigger_hook(["pre-create"], conn, %{
         "Upload" => %{"MetaData" => %{"user_id" => user_id, "filename_token" => token}}
       }) do
    with {:ok, _} <- validate_user_id(user_id),
         {:ok, _} <- Druid.find_id_by_token(token),
         %User{} <- Accounts.find_user(user_id),
         {:ok, _} <- Resources.get_asset_by_token(token) do
      
      Logger.info("""
      #{inspect __MODULE__}[pre-create]:
      Upload allowed for asset #{inspect token}\
      """)
      send_resp(conn, 204, "OK")
    else
      e ->
        Logger.info("""
        #{inspect __MODULE__}[pre-create]:
        Upload not allowed - #{inspect e}
        """)
        send_resp(conn, 403, "Forbidden")
    end
  end

And this is how it works: the hook worked successfully and it looks like it will send 204 response, but after 2ms this exception was raised. The client receives 500 status response

Even if i do this then get the same:

conn
|> send_resp(204, "OK")
|> halt()

[José Valim]

Can you please provide a small application that reproduces the error? Something we can run locally and take a further look at it. Thanks.

[Sviatoslav Flud]

The problem was in 204 response body(need to be "") phoenixframework/phoenix#1131 (comment)

[Sviatoslav Flud]

@josevalim Thanks for your response