@ParameterizedTest annotation in JUnit - Test Execution Trace

Test Overview

This test uses the @ParameterizedTest annotation to run the same test method multiple times with different input values. It verifies that the isEven method correctly identifies even numbers.

Test Code - JUnit 5

JUnit

import static org.junit.jupiter.api.Assertions.assertTrue;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;

public class NumberUtilsTest {

    public static boolean isEven(int number) {
        return number % 2 == 0;
    }

    @ParameterizedTest
    @ValueSource(ints = {2, 4, 6, 8, 10})
    void testIsEvenWithEvenNumbers(int number) {
        assertTrue(isEven(number), "Number should be even");
    }
}

Execution Trace - 7 Steps

Step	Action	System State	Assertion	Result
1	Test runner starts and identifies the @ParameterizedTest method	JUnit test environment ready to run parameterized tests	-	PASS
2	Runs testIsEvenWithEvenNumbers with input 2	Method isEven called with 2	assertTrue(isEven(2)) checks if 2 is even	PASS
3	Runs testIsEvenWithEvenNumbers with input 4	Method isEven called with 4	assertTrue(isEven(4)) checks if 4 is even	PASS
4	Runs testIsEvenWithEvenNumbers with input 6	Method isEven called with 6	assertTrue(isEven(6)) checks if 6 is even	PASS
5	Runs testIsEvenWithEvenNumbers with input 8	Method isEven called with 8	assertTrue(isEven(8)) checks if 8 is even	PASS
6	Runs testIsEvenWithEvenNumbers with input 10	Method isEven called with 10	assertTrue(isEven(10)) checks if 10 is even	PASS
7	All parameterized test cases completed successfully	Test report shows all inputs passed	-	PASS

Failure Scenario

Failing Condition: If the isEven method returns false for any even number input

Execution Trace Quiz - 3 Questions

What does the @ParameterizedTest annotation do in this test?

A Runs the test method multiple times with different inputs

B Runs the test method only once

C Skips the test method

D Runs the test method only if a condition is true

Key Result

Using @ParameterizedTest with @ValueSource helps test the same logic with multiple inputs efficiently, reducing code duplication and improving test coverage.