learning-haskell/14-testing/14.7-chapter-exercises.md

Chapter Excercises

Validating numbers into words

see src/wordnumbertest.hs

Using QuickCheck

see src/proptest.hs

Failure

This will fill due to precision. sqrt 2 cannot be accurately represented, so it is rounded to a ration number. This rounding error causes a different when squaring it.

Idempotence

see src/idempotence.hs

Hangman testing

see hangman/test/tests.hs

Validating ciphers

No code available, but the principle is easy:

1. Create generator for the input (limited to a-z and A-Z)
2. Create generator for the caesar key (limited to 0-25)
3. Create generator for vigenere key (limited to a-z)
4. quickCheck the properties that decode after encode is the identity