assertTrue and assertFalse in JUnit - Test Execution Trace

Test Overview

This test checks if a number is positive using assertTrue and if a number is negative using assertFalse. It verifies that the conditions about the number's sign are correct.

Test Code - JUnit 5

JUnit

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;

public class NumberSignTest {

    @Test
    public void testNumberSign() {
        int number = 5;
        assertTrue(number > 0, "Number should be positive");

        int negativeNumber = -3;
        assertFalse(negativeNumber > 0, "Number should not be positive");
    }
}

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts	JUnit test runner is ready to execute the test method	-	PASS
2	Assign number = 5	Variable 'number' holds value 5	-	PASS
3	assertTrue(number > 0)	Check if 5 > 0	Verify condition 'number > 0' is true	PASS
4	Assign negativeNumber = -3	Variable 'negativeNumber' holds value -3	-	PASS
5	assertFalse(negativeNumber > 0)	Check if -3 > 0	Verify condition 'negativeNumber > 0' is false	PASS
6	Test ends successfully	All assertions passed	-	PASS

Failure Scenario

Failing Condition: If number is not greater than 0 for assertTrue or if negativeNumber is greater than 0 for assertFalse

Execution Trace Quiz - 3 Questions

What does assertTrue(number > 0) check in the test?

A That number is positive

B That number is negative

C That number equals zero

D That number is less than zero

Key Result

Use assertTrue to confirm a condition is true and assertFalse to confirm a condition is false. This helps clearly check expected boolean conditions in tests.