Decision table testing in Testing Fundamentals - Test Execution Trace

Test Overview

This test checks a simple calculator's behavior using decision table testing. It verifies that the calculator correctly adds or subtracts two numbers based on the selected operation.

Test Code - unittest

Testing Fundamentals

import unittest

class Calculator:
    def calculate(self, num1, num2, operation):
        if operation == 'add':
            return num1 + num2
        elif operation == 'subtract':
            return num1 - num2
        else:
            raise ValueError('Invalid operation')

class TestCalculator(unittest.TestCase):
    def setUp(self):
        self.calc = Calculator()

    def test_addition(self):
        result = self.calc.calculate(5, 3, 'add')
        self.assertEqual(result, 8)

    def test_subtraction(self):
        result = self.calc.calculate(5, 3, 'subtract')
        self.assertEqual(result, 2)

    def test_invalid_operation(self):
        with self.assertRaises(ValueError):
            self.calc.calculate(5, 3, 'multiply')

if __name__ == '__main__':
    unittest.main()

Execution Trace - 8 Steps

Step	Action	System State	Assertion	Result
1	Test starts - unittest framework initializes TestCalculator	Test environment ready, Calculator instance created	-	PASS
2	Calls calculate(5, 3, 'add')	Calculator receives inputs num1=5, num2=3, operation='add'	-	PASS
3	Calculator performs addition and returns 8	Result = 8	Check if result == 8	PASS
4	Calls calculate(5, 3, 'subtract')	Calculator receives inputs num1=5, num2=3, operation='subtract'	-	PASS
5	Calculator performs subtraction and returns 2	Result = 2	Check if result == 2	PASS
6	Calls calculate(5, 3, 'multiply') expecting error	Calculator receives inputs num1=5, num2=3, operation='multiply'	Check if ValueError is raised	PASS
7	ValueError raised due to invalid operation	Exception caught by test	Exception matches expected ValueError	PASS
8	All tests complete	Test report generated with 3 tests passed	-	PASS

Failure Scenario

Failing Condition: Calculator returns wrong result or does not raise error for invalid operation

Execution Trace Quiz - 3 Questions

What does the test check when calling calculate(5, 3, 'add')?

A That an error is raised

B That the result is 8

C That the result is 2

D That the inputs are ignored

Key Result

Decision table testing helps cover all possible input combinations and expected outcomes systematically, ensuring no case is missed.