:invalid_mfa when calling Supervisor.start_child

Question

I'm trying to start a child process in Elixir, and am receiving the following error:

{:error, {:invalid_mfa, {Worker, :start_link, "MY_TEAM_ID"}}}

My supervisor code looks something like this:

DynamicSupervisor.start_child(Worker.Supervisor, {Worker, "MY_TEAM_ID"})

Answer 1

From the error message, the child_spec is supposed to pass its arguments as a list. Instead it should be {:error, {:invalid_mfa, {Worker, :start_link, ["MY_TEAM_ID"]}}} (note the [] around the params)

Inside your Worker module, check your child_spec function. It should look something like this (again, note the [] around team_id):

def child_spec(team_id) do
    %{
      id: __MODULE__,
      start: {__MODULE__, :start_link, [team_id]},
      type: :worker
    }
end