@EnabledOnOs for OS-specific tests in JUnit - Test Execution Trace

Test Overview

This test checks that a method runs only on Windows OS using the @EnabledOnOs annotation. It verifies the test is skipped on other operating systems.

Test Code - JUnit 5

JUnit

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.condition.EnabledOnOs;
import org.junit.jupiter.api.condition.OS;
import static org.junit.jupiter.api.Assertions.assertTrue;

public class OsSpecificTest {

    @Test
    @EnabledOnOs(OS.WINDOWS)
    void testRunsOnlyOnWindows() {
        String osName = System.getProperty("os.name").toLowerCase();
        assertTrue(osName.contains("windows"), "Test should run only on Windows OS");
    }
}

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test runner starts and detects the test method annotated with @EnabledOnOs(OS.WINDOWS)	JUnit test environment initialized	-	PASS
2	JUnit checks the current OS from System.getProperty("os.name")	System property os.name is read, e.g., "Windows 10" or "Linux"	-	PASS
3	JUnit compares current OS with the annotation condition (Windows)	OS matches Windows if running on Windows, else does not match	-	PASS
4	If OS matches Windows, test method executes and asserts os.name contains "windows"	Test method runs on Windows OS	assertTrue(osName.contains("windows"))	PASS
5	If OS does not match Windows, test is skipped by JUnit	Test method is not executed on non-Windows OS	-	PASS

Failure Scenario

Failing Condition: Test runs on a non-Windows OS because annotation is missing or misconfigured

Execution Trace Quiz - 3 Questions

What does the @EnabledOnOs(OS.WINDOWS) annotation do in this test?

A Runs the test on all operating systems

B Runs the test only on Windows OS

C Disables the test on Windows OS

D Runs the test only on Linux OS

Key Result

Use @EnabledOnOs to run tests only on specific operating systems, preventing irrelevant test failures on other platforms.