glytching / junit-extensions

import org.junit.jupiter.api.extension.AfterTestExecutionCallback;

import org.junit.jupiter.api.extension.BeforeTestExecutionCallback;

import org.junit.jupiter.api.extension.ExtensionContext;

import java.lang.reflect.Field;

import java.util.Optional;

import static org.junit.platform.commons.support.AnnotationSupport.isAnnotated;

/**

 * The test name extension makes the current test name available inside each test method.

 *

 * <p>Usage example:

 *

 * <p>Injecting random values as fields:

 *

 * <pre>

 * @ExtendWith(TestNameExtension.class)

 * public class MyTest {

 *

 *     @TestName

 *     private String testName;

 *

 *     @Test

 *     public void testUsingRandomString() {

 *         // use the populated testName

 *         // ...

 *     }

 * }

 * </pre>

 *

 * @since 1.1.0

 */

public class TestNameExtension implements BeforeTestExecutionCallback, AfterTestExecutionCallback {

  @Override

  public void beforeTestExecution(ExtensionContext extensionContext) throws Exception {

    setTestNameFieldValue(

        getTestNameField(extensionContext),

        extensionContext.getRequiredTestInstance(),

        extensionContext.getRequiredTestMethod().getName());

  }

  private Optional<Field> getTestNameField(ExtensionContext extensionContext) {

    for (Field field : extensionContext.getRequiredTestClass().getDeclaredFields()) {

      if (isAnnotated(field, TestName.class)) {

        return Optional.of(field);

      }

    }

    return Optional.empty();

  }

  @SuppressWarnings("OptionalUsedAsFieldOrParameterType")

  private void setTestNameFieldValue(

      Optional<Field> testNameField, Object testInstance, String value) throws IllegalAccessException {

    if (testNameField.isPresent()) {

      testNameField.get().setAccessible(true);

      testNameField.get().set(testInstance, value);

    }

  }

}