CI pipeline test stage in JUnit - Build an Automation Script

Verify CI pipeline test stage runs unit tests and reports results

Preconditions (2)

Step 1: Trigger the CI pipeline manually or by pushing code

Step 2: Wait for the test stage to start and complete

Step 3: Check the test stage logs for test execution details

Step 4: Verify that all unit tests are executed

Step 5: Verify that the test results are reported in the CI system

✅ Expected Result: The test stage completes successfully with all unit tests run and results reported without errors

Automation Requirements - JUnit 5

Assertions Needed:

Assert that all expected test methods are executed

Assert that no tests failed

Assert that test results are generated and accessible

Best Practices:

Use @Test annotations for test methods

Use assertions from org.junit.jupiter.api.Assertions

Keep tests independent and repeatable

Use descriptive test method names

Automated Solution

JUnit

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

public class SampleUnitTest {

    @Test
    void testAddition() {
        int result = 2 + 3;
        assertEquals(5, result, "2 + 3 should equal 5");
    }

    @Test
    void testStringContains() {
        String text = "Hello CI Pipeline";
        assertTrue(text.contains("CI"), "Text should contain 'CI'");
    }

    @Test
    void testArrayNotEmpty() {
        int[] numbers = {1, 2, 3};
        assertNotEquals(0, numbers.length, "Array should not be empty");
    }

}

This JUnit 5 test class SampleUnitTest contains three simple unit tests.

Each test method is annotated with @Test so the CI pipeline test stage will detect and run them automatically.

Assertions check expected outcomes: assertEquals verifies addition, assertTrue checks string content, and assertNotEquals ensures the array is not empty.

When the CI pipeline runs mvn test, it will execute these tests and report results. If all assertions pass, the test stage will succeed.

This setup ensures the CI pipeline test stage runs unit tests and reports results as expected.

Common Mistakes - 4 Pitfalls

Not using @Test annotation on test methods

Using System.out.println instead of assertions

Writing dependent tests that rely on execution order

Ignoring test failures in CI pipeline logs

Bonus Challenge

Now add data-driven testing with 3 different inputs for a method that checks if a number is even

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