The exercise contains the requirement as stated:
" Step 3
The weakest link in any cipher is the human being. Let’s make your substitution cipher a little more fault tolerant by providing a source of randomness and ensuring that the key contains only lowercase letters.
If someone doesn’t submit a key at all, generate a truly random key of at least 100 lowercase characters in length."
If having implemented this feature test fail with:
"
— FAIL: TestVigenereWrongKey (0.00s)
simple_cipher_test.go:135: NewVigenere(“”): got non-nil, want nil
"
Could you, please, fix either requirements or test -cases?
Hopefully, I don’t get it wrong, if I do, please, feel free to let me know