Testing no exception thrown in JUnit - Test Execution Trace

Test Overview

This test verifies that a method completes without throwing any exceptions. It ensures the code runs smoothly under normal conditions.

Test Code - JUnit

JUnit

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

public class NoExceptionTest {

    public void methodThatShouldNotThrow() {
        // Simulate normal operation
        int a = 5;
        int b = 10;
        int c = a + b; // simple operation
    }

    @Test
    public void testMethodDoesNotThrowException() {
        assertDoesNotThrow(() -> methodThatShouldNotThrow());
    }
}

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	Test starts	JUnit test runner initialized	-	PASS
2	JUnit runner calls testMethodDoesNotThrowException()	Inside test method	-	PASS
3	assertDoesNotThrow executes methodThatShouldNotThrow()	methodThatShouldNotThrow runs without errors	No exception thrown during method execution	PASS
4	Test completes successfully	Test runner ready for next test	assertDoesNotThrow confirms no exceptions	PASS

Failure Scenario

Failing Condition: methodThatShouldNotThrow() throws an exception

Execution Trace Quiz - 3 Questions

What does assertDoesNotThrow verify in this test?

A That the method throws a specific exception

B That the method returns a specific value

C That the method runs without throwing any exceptions

D That the method runs slower than expected

Key Result

Use assertDoesNotThrow to clearly verify that a method runs without exceptions, making tests easier to understand and maintain.