Introduce demos for user-supplied lifecycle callback methods

Issue: #1620

Author: sbrannen

documentation/src/test/java/example/callbacks/AbstractDatabaseTests.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.callbacks;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+
+/**
+ * Abstract base class for tests that use the database.
+ */
+abstract class AbstractDatabaseTests {
+
+	@BeforeEach
+	void connectToDatabase() {
+		System.out.println("  @BeforeEach " + AbstractDatabaseTests.class.getSimpleName() + ".connectToDatabase()");
+	}
+
+	@AfterEach
+	void disconnectFromDatabase() {
+		System.out.println("  @AfterEach " + AbstractDatabaseTests.class.getSimpleName() + ".disconnectFromDatabase()");
+	}
+
+}

documentation/src/test/java/example/callbacks/BrokenLifecycleMethodConfigDemo.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.callbacks;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+/**
+ * Example of "broken" lifecycle method configuration.
+ *
+ * <p>Test data is inserted before the database connection has been opened.
+ *
+ * <p>Database connection is closed before deleting test data.
+ */
+@ExtendWith({ Extension1.class, Extension2.class })
+class BrokenLifecycleMethodConfigDemo {
+
+	@BeforeEach
+	void connectToDatabase() {
+		System.out.println("  @BeforeEach " + getClass().getSimpleName() + ".connectToDatabase()");
+	}
+
+	@BeforeEach
+	void insertTestDataIntoDatabase() {
+		System.out.println("  @BeforeEach " + getClass().getSimpleName() + ".insertTestDataIntoDatabase()");
+	}
+
+	@Test
+	void testDatabaseFunctionality() {
+		System.out.println("    @Test " + getClass().getSimpleName() + ".testDatabaseFunctionality()");
+	}
+
+	@AfterEach
+	void deleteTestDataInDatabase() {
+		System.out.println("  @AfterEach " + getClass().getSimpleName() + ".deleteTestDataInDatabase()");
+	}
+
+	@AfterEach
+	void disconnectFromDatabase() {
+		System.out.println("  @AfterEach " + getClass().getSimpleName() + ".disconnectFromDatabase()");
+	}
+
+}

documentation/src/test/java/example/callbacks/DatabaseTestsDemo.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.callbacks;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+/**
+ * Extension of {@link AbstractDatabaseTests} that inserts test data
+ * into the database (after the database connection has been opened)
+ * and deletes test data (before the database connection is closed).
+ */
+@ExtendWith({ Extension1.class, Extension2.class })
+class DatabaseTestsDemo extends AbstractDatabaseTests {
+
+	@BeforeEach
+	void insertTestDataIntoDatabase() {
+		System.out.println("  @BeforeEach " + getClass().getSimpleName() + ".insertTestDataIntoDatabase()");
+	}
+
+	@Test
+	void testDatabaseFunctionality() {
+		System.out.println("    @Test " + getClass().getSimpleName() + ".testDatabaseFunctionality()");
+	}
+
+	@AfterEach
+	void deleteTestDataInDatabase() {
+		System.out.println("  @AfterEach " + getClass().getSimpleName() + ".deleteTestDataInDatabase()");
+	}
+
+}

documentation/src/test/java/example/callbacks/Extension1.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.callbacks;
+
+import org.junit.jupiter.api.extension.AfterEachCallback;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+public class Extension1 implements BeforeEachCallback, AfterEachCallback {
+
+	@Override
+	public void beforeEach(ExtensionContext context) {
+		System.out.println(getClass().getSimpleName() + ".beforeEach()");
+	}
+
+	@Override
+	public void afterEach(ExtensionContext context) {
+		System.out.println(getClass().getSimpleName() + ".afterEach()");
+	}
+
+}

documentation/src/test/java/example/callbacks/Extension2.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.callbacks;
+
+import org.junit.jupiter.api.extension.AfterEachCallback;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+public class Extension2 implements BeforeEachCallback, AfterEachCallback {
+
+	@Override
+	public void beforeEach(ExtensionContext context) {
+		System.out.println(getClass().getSimpleName() + ".beforeEach()");
+	}
+
+	@Override
+	public void afterEach(ExtensionContext context) {
+		System.out.println(getClass().getSimpleName() + ".afterEach()");
+	}
+
+}