Not sure what it's called?

[erlandsona]

I've got a function in my demo app which I have spec'd to take any atom, and a branch which checks if it's in a subset of terms to create my struct, otherwise it will raise an ArgumentError. But this won't type check I'm assuming for similar reasons as my previous issue... But for reference, here's the snippet I changed to a stack of or's cause I thought it might have to do with st in [:a, :b, :c, :d, :etc] but same error either way.

  @spec new!(atom()) :: t() | no_return()
  def new!(st) do
    if st == :oregon or
         st == :washington or
         st == :colorado or
         st == :tennessee or
         st == :new_york do
      %__MODULE__{_: st}
    else
      raise(ArgumentError, "Unrecognized state")
    end
  end

errors with

❌  St.new!/1
   |
   | type `%St{_: atom()}` not match with union type `%St{_: :washington | :tennessee | :oregon | :new_york | :colorado}`
   |
   | at unknown_file:?