Definition
To add additional expectation helpers, define a function that returns a boolean and register it:
import expecter
def can_meow(actual_value):
return actual_value in {'cat', 'kitten'}
expecter.add_expectation(can_meow)
Usage
Custom helpers are available on the expect
object:
>>> expect('kitten').can_meow()
>>> expect('puppy').can_meow()
Traceback (most recent call last):
...
AssertionError: Expected that 'puppy' can meow, but it can't