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Testing & modern typing

pytest basics, mocks, type hints, TypedDict, Protocol, and static-checking patterns.

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How to Use Mock Flip Mutation Testing in Python

Demonstrates how mutation testing tools flip Boolean literals (mock flip) in Python source to verify test suite effectiveness in catching logic changes.

mutation-testing testing bool
Python 
import random

# In mutation testing, a "mock flip" intentionally changes a Boolean
# constant to False (or True) to see if the test suite catches it.
# This is a common "constant mutation" applied to a source file's literals.

def is_even(n: int) -> bool:
    """Return True if n is even. Contains a Boolean literal us…
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