@Order for execution order in JUnit - Test Execution Trace

Test Overview

This test demonstrates how to use the @Order annotation in JUnit 5 to control the order in which test methods run. It verifies that tests execute in the specified sequence.

Test Code - JUnit

JUnit

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

@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
public class OrderedTests {

    private static StringBuilder executionOrder = new StringBuilder();

    @Test
    @Order(2)
    void secondTest() {
        executionOrder.append("B");
        assertTrue(true);
    }

    @Test
    @Order(1)
    void firstTest() {
        executionOrder.append("A");
        assertTrue(true);
    }

    @Test
    @Order(3)
    void thirdTest() {
        executionOrder.append("C");
        assertEquals("ABC", executionOrder.toString());
    }
}

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	JUnit test runner starts and reads @TestMethodOrder annotation	JUnit recognizes tests will run in @Order sequence	-	PASS
2	Runs firstTest() annotated with @Order(1)	executionOrder is empty	assertTrue(true) always passes	PASS
3	Runs secondTest() annotated with @Order(2)	executionOrder contains "A" from firstTest	assertTrue(true) always passes	PASS
4	Runs thirdTest() annotated with @Order(3)	executionOrder contains "AB" from previous tests	assertEquals("ABC", executionOrder.toString()) verifies order	PASS

Failure Scenario

Failing Condition: If tests do not run in the specified @Order sequence, the final assertion in thirdTest fails

Execution Trace Quiz - 3 Questions

What does the @Order annotation control in JUnit tests?

A The timeout duration for tests

B The order in which test methods are executed

C The priority of test failures

D The number of times a test runs

Key Result

Using @Order with @TestMethodOrder(MethodOrderer.OrderAnnotation.class) ensures predictable test execution order, which is useful when tests depend on sequence.