Unit Testing/Pytest/Test Exceptions

Create a Python Program

Create the following Python program. Save it as multiply.py

def multiply(x, y):
    result = x * y
    return result


def main():
    multiplicand = float(input("Enter a multiplicand: "))
    multiplier = float(input("Enter a multiplier: "))
    product = multiply(multiplicand, multiplier)
    print(f"The product is: {product}")


if __name__ == "__main__":
    main()

Create a Test Program

Create the following Pytest test program. Save it as test_multiply.py

import pytest
import multiply


def test_invalid_input():
    input_values = [
        "2",
        "X"
    ]

    def input(prompt=None):
        return input_values.pop(0)

    multiply.input = input

    with pytest.raises(ValueError):
        multiply.main()

Test Success

Test the program by running pytest in a terminal or command prompt in the same folder as the two programs above and observe the results.

pytest

Test Failure

Change the test source code somehow, such as replacing the invalid input with valid input. Test the program by running pytest again and observe the results.

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Unit Testing/Pytest

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