Parameterized testing with ExUnit

I do not get why do you need attribute at all. Why not:

for {lhs, rhs} <- [{"one", 1}, {"two", 2}, {"three", 3}] do
  test "#{lhs} convert to #{rhs}" do
    assert unquote(lhs) == unquote(rhs)
  end
end

Because I have never thought it until you mentioned.
It seems the code that you write is more smarter than I write. I use it.
Thanks a lot

That’s a metaprogramming feature - unquote fragments, which provide an easy way to generate code dynamically.

Learn more at unquote fragments.

If you are interested in metaprogramming, you can:

• grasp the basic concepts from the doc of quote/2.
• dig in depth with the book - Metaprogramming Elixir (Although it is published at 2015, the contents of it still match the current version of Elixir.)

(And, welcome