child_spec.ex

# Without specifying a child_spec, you get the default one:
# default = %{
#   id: __MODULE__,
#   start: {__MODULE__, :start_link, [init_arg]}
# }

# A: calls start_link/1 with empty list of args
# children = [
#   DevWorker
# ]
#
# "start_link/1"
# []

# B: Calls start_link/1 with single arg
# children = [
#   {DevWorker, :foo}
# ]
#
# "start_link/1"
# :foo

# C: Calls start_link/1 with the same list of args
# children = [
#   {DevWorker, [:foo, :bar]}
# ]
#
# "start_link/1"
# [:foo, :bar]


# With a custom child_spec:
#
# def child_spec([a, b]) do
#   %{
#     id: make_ref(),
#     start: {__MODULE__, :start_link, [a, b]}
#   }
# end
#
# children = [
#   {DevWorker, [:foo, :bar]}
# ]
#
# "start_link/2"
# :foo
# :bar

def child_spec([a, b]) do
  %{
    id: make_ref(),
    start: {__MODULE__, :start_link, [a, b]}
  }
end

def start_link(a) do
  IO.inspect("start_link/1")
  IO.inspect(a)
end

def start_link(a, b) do
  IO.inspect("start_link/2")
  IO.inspect(a)
  IO.inspect(b)
end