Few negative mnemonic test cases

[piotr-iohk]

Issue Number

#94

Overview

• I have added few negative mnemonic test cases

Comments

Well, I don't know, but I was expecting that code coverage will slightly improve but it stayed the same :(
I was expecting to get coverage on those two lefts below but hpc still shows ErrMnemonicWords and ErrDictionary not executed...

  163 mkMnemonic wordsm = do
  164     phrase <- left ErrMnemonicWords
  165         $ mnemonicPhrase @mw (toUtf8String <$> wordsm)
  166 
  167     sentence <- left ErrDictionary
  168         $ mnemonicPhraseToMnemonicSentence Dictionary.english phrase

[KtorZ]

@piotr-iohk I believe the coverage didn't improve here because you aren't actually evaluating the errors but just, verifying that the constructor yields a Left. So GHC doesn't need to go much further in the evaluation steps and what errors is actually triggered isn't tested 😉

So, we do need a stronger assertion than isLeft, likely, a strong equality.

[piotr-iohk]

@KtorZ, I have added expectations against specific values where I could. Code coverage now increased indeed 👍

The only error I was not able to produce was UnexpectedEntropyError in:

genEntropy =
       let
           size =
              fromIntegral $ ambiguousNatVal @n
           eitherToIO =
               either (throwM . UnexpectedEntropyError) return
       in
           (eitherToIO . mkEntropy) =<< Crypto.getEntropy (size `div` 8)

[KtorZ]

🎉