Top Secret could use another test

[krstopro]

Exercise Top Secret, decode_secret_message_part/2 function. I believe there should be another test when the AST (the first argument of the fucntion) is formed from the code consisting of only primitive types such as 12 or :ok.
For example, if ast = TopSecret.to_ast("12") or ast = TopSecret.to_ast(":ok"), then TopSecret.decode_secret_message_part(ast, acc) should return {ast, acc}. However, there is no test for that; all the tests assume that the AST is formed from the code containing a function. One could pass all the tests even though the function raises an ArgumentError for such an argument. This test could as well help the solver with task the Task 5 of the exercise as some nodes simply contain only primitive types; took me quite some time to notice that one should check if the ast in the function is actually a tuple.

I am willing to do this myself, but if I am correct one should first open an issue here.

[angelikatyborska]

Hi! Thank you for the suggestion - it's a very good one. I would be very happy to see a PR from you with that improvement 🙂. The new test should be a separate test case, probably added after the existing "returns the AST and accumulator unchanged" test.

[krstopro]

Done! I will ask you to review the PR.