foo.ex

with 
  {:ok, width} <- Map.fetch(opts, :width),
  {:ok, height} <- Map.fetch(opts, :height) 
do 
  {:ok, width * height}
else
  {:error, :wrong_data} -> ...
  {:error, :wrong_data_2} -> ...
end

## Ou

my_pipe 
|> bar(123)
|> bee(456)

bar({:error, reason}, _), do: {:error, reason}
bar(arg, foo), do: arg + foo

bee({:error, reason}, _), do: {:error, reason}
bee(arg, fee), do: arg + fee