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Testing & modern typing

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Testing & modern typing easy

Fix and Test a Regression Bug in Python with Unit Tests

This code implements a circle area function that raises ValueError for negative radii, then runs basic tests and a regression check for that edge case.

regression-testing unit-testing math
Python 
import math

def calculate_area(radius):
    """Calculate the area of a circle given its radius."""
    if radius < 0:
        raise ValueError("Radius cannot be negative")
    return math.pi * radius ** 2

def main():
    test_cases = [0, 1, 2.5, 5, 10]
    
    print("Circle Area Calculator")
    print("-" * 30)
   …
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