How to division operator scenario when denominator is zero , or both numerator and denominator are zero?

Question

I am trying to do TDD in haskell using HSpec. So while writing special case scenario for division operator for example:

• 3 / 0 => Infinity
• 0 / 0 => Nan

How to test the above cases using Hspec ?

Answer 1

Use the functions isInfinite and isNaN:

Prelude> isInfinite (3 / 0.0)
True
Prelude> isNaN (0.0/0.0)
True