A Validator
that passes only for NaN
values.
Nan = require "Nan"
Nan.test 0 # => false
Nan.test NaN # => true
# Since using `isType` with the built-in Number constructor allows NaN values, we need a validator that is the exact opposite of `Nan`.
{Number} = Nan
Number.test 0 # => true
Number.test NaN # => false