@EnabledIfSystemProperty in JUnit - Build an Automation Script

Test runs only if system property 'env' equals 'test'

Preconditions (2)

Step 1: Set system property 'env' to 'test'

Step 2: Run the test class containing the conditional test method

Step 3: Observe that the test method annotated with @EnabledIfSystemProperty runs

Step 4: Set system property 'env' to 'prod'

Step 5: Run the test class again

Step 6: Observe that the test method annotated with @EnabledIfSystemProperty is skipped

✅ Expected Result: The test method runs only when system property 'env' is 'test'. It is skipped otherwise.

Automation Requirements - JUnit 5

Assertions Needed:

Verify test method executes only when system property 'env' equals 'test'

Verify test method is skipped when system property 'env' is not 'test'

Best Practices:

Use @EnabledIfSystemProperty annotation correctly with 'named' and 'matches' attributes

Use assertions inside the test to confirm execution

Use @BeforeAll or @BeforeEach to set or clear system properties if needed

Keep tests independent and clean up system properties after tests

Automated Solution

JUnit

import org.junit.jupiter.api.*;
import org.junit.jupiter.api.condition.EnabledIfSystemProperty;

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

public class EnabledIfSystemPropertyTest {

    @BeforeEach
    void clearProperty() {
        System.clearProperty("env");
    }

    @Test
    @EnabledIfSystemProperty(named = "env", matches = "test")
    void testRunsOnlyIfEnvIsTest() {
        // This test runs only if system property 'env' equals 'test'
        String env = System.getProperty("env");
        assertTrue("test".equals(env), "System property 'env' should be 'test'");
    }

    @Test
    void testAlwaysRuns() {
        // Control test to show normal test execution
        assertTrue(true);
    }

    public static void main(String[] args) {
        // Example to run tests with system property set
        System.setProperty("env", "test");
        org.junit.platform.launcher.LauncherDiscoveryRequest request =
                org.junit.platform.engine.discovery.DiscoverySelectors.selectClass(EnabledIfSystemPropertyTest.class);
        // Normally tests run via IDE or build tool
    }
}

The test class EnabledIfSystemPropertyTest contains a test method testRunsOnlyIfEnvIsTest annotated with @EnabledIfSystemProperty. This annotation makes the test run only if the system property named env matches the value test.

Before each test, the system property env is cleared to avoid side effects. To run the conditional test, set the system property env to test before running the tests.

The assertion inside the test confirms that the system property is indeed test when the test runs.

Another test testAlwaysRuns is included to show a normal test that always runs.

This setup helps beginners understand how to use @EnabledIfSystemProperty to conditionally run tests based on environment settings.

Common Mistakes - 4 Pitfalls

Not setting the system property before running the test

Using incorrect property name or value in @EnabledIfSystemProperty

Not clearing or resetting system properties after tests

Putting assertions outside the conditional test method

Bonus Challenge

Now add data-driven testing with 3 different system property values ('test', 'dev', 'prod') and verify which tests run.

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