Skip to main content

JUnit Test Cases Should Call Super Methods

High
reliabilityconsistency

What is it?​

This practice is triggered when a JUnit test case that overrides setUp or tearDown methods fails to explicitly call the corresponding super method.

Why apply it?​

Overriding these methods without calling super.setUp() or super.tearDown() can lead to inconsistent test setup and teardown procedures, potentially causing tests to fail or behave unpredictably as shared logic from the parent class is skipped.

How to fix it?​

Explicitly call super.setUp() and super.tearDown() at the beginning of your overriding methods to ensure that any necessary setup or cleanup logic from the parent class is executed.

Examples​

Example 1:​

Negative​

The negative example shows a JUnit test case where the setUp method fails to call super.setUp(), omitting important initializations performed by the parent class.

public class DatabaseTest extends BaseTest {

  private DatabaseConnection dbConnection;

  @Override
  protected void setUp() throws Exception { // Noncompliant
    dbConnection = new DatabaseConnection("test-database");
    dbConnection.initialize();
  }
}

Example 2:​

Positive​

The positive example shows a JUnit test case where the setUp method correctly calls super.setUp() to include any setup logic defined in the parent class.

public class DatabaseTest extends BaseTest {

  private DatabaseConnection dbConnection;

  @Override
  protected void setUp() throws Exception {
    super.setUp(); // Compliant
    dbConnection = new DatabaseConnection("test-database");
    dbConnection.initialize();
  }
}

Negative​

In the negative example, the tearDown method neglects to call super.tearDown(), potentially leaving resources from the parent class unhandled.

public class ServiceTest extends AbstractTestSetup {

  private MockService service;

  @Override
  protected void tearDown() throws Exception { // Noncompliant
    if (service != null) {
      service.shutdown();
    }
  }
}

Example 3:​

Positive​

The positive example demonstrates a correct implementation of the tearDown method where super.tearDown() is properly invoked to ensure cleanup logic from the parent class is executed.

public class ServiceTest extends AbstractTestSetup {

  private MockService service;

  @Override
  protected void tearDown() throws Exception {
    if (service != null) {
      service.shutdown();
    }
    super.tearDown(); // Compliant
  }
}