DelegatingServerLogoutHandler

Create a ServerLogoutHandler which delegates to a group of
ServerLogoutHandler implementations.

Fixes gh-4839

web/src/main/java/org/springframework/security/web/server/authentication/logout/DelegatingServerLogoutHandler.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.web.server.authentication.logout;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.springframework.security.core.Authentication;
+import org.springframework.security.web.server.WebFilterExchange;
+import org.springframework.util.Assert;
+
+import reactor.core.publisher.Mono;
+
+/**
+ * Delegates to a collection of {@link ServerLogoutHandler} implementations.
+ *
+ * @author Eric Deandrea
+ * @since 5.1
+ */
+public class DelegatingServerLogoutHandler implements ServerLogoutHandler {
+	private final List<ServerLogoutHandler> delegates;
+
+	public DelegatingServerLogoutHandler(ServerLogoutHandler... delegates) {
+		Assert.notEmpty(delegates, "delegates cannot be null or empty");
+		this.delegates = Arrays.asList(delegates);
+	}
+
+	@Override
+	public Mono<Void> logout(WebFilterExchange exchange, Authentication authentication) {
+		Stream<Mono<Void>> results = this.delegates.stream().map(delegate -> delegate.logout(exchange, authentication));
+		return Mono.when(results.collect(Collectors.toList()));
+	}
+}

web/src/test/java/org/springframework/security/web/server/authentication/logout/DelegatingServerLogoutHandlerTests.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.web.server.authentication.logout;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.Mockito.*;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import org.springframework.security.core.Authentication;
+import org.springframework.security.web.server.WebFilterExchange;
+
+import reactor.test.publisher.PublisherProbe;
+
+/**
+ * @author Eric Deandrea
+ * @since 5.1
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class DelegatingServerLogoutHandlerTests {
+	@Mock
+	private ServerLogoutHandler delegate1;
+
+	@Mock
+	private ServerLogoutHandler delegate2;
+	private PublisherProbe<Void> delegate1Result = PublisherProbe.empty();
+	private PublisherProbe<Void> delegate2Result = PublisherProbe.empty();
+
+	@Mock
+	private WebFilterExchange exchange;
+
+	@Mock
+	private Authentication authentication;
+
+	@Before
+	public void setup() {
+		when(this.delegate1.logout(any(WebFilterExchange.class), any(Authentication.class))).thenReturn(this.delegate1Result.mono());
+		when(this.delegate2.logout(any(WebFilterExchange.class), any(Authentication.class))).thenReturn(this.delegate2Result.mono());
+	}
+
+	@Test
+	public void constructorWhenNullThenIllegalArgumentException() {
+		assertThatThrownBy(() -> new DelegatingServerLogoutHandler((ServerLogoutHandler[]) null))
+				.isExactlyInstanceOf(IllegalArgumentException.class)
+				.hasMessage("delegates cannot be null or empty")
+				.hasNoCause();
+	}
+
+	@Test
+	public void constructorWhenEmptyThenIllegalArgumentException() {
+		assertThatThrownBy(() -> new DelegatingServerLogoutHandler(new ServerLogoutHandler[0]))
+				.isExactlyInstanceOf(IllegalArgumentException.class)
+				.hasMessage("delegates cannot be null or empty")
+				.hasNoCause();
+	}
+
+	@Test
+	public void logoutWhenSingleThenExecuted() {
+		DelegatingServerLogoutHandler handler = new DelegatingServerLogoutHandler(this.delegate1);
+		handler.logout(this.exchange, this.authentication).block();
+
+		this.delegate1Result.assertWasSubscribed();
+	}
+
+	@Test
+	public void logoutWhenMultipleThenExecuted() {
+		DelegatingServerLogoutHandler handler = new DelegatingServerLogoutHandler(this.delegate1, this.delegate2);
+		handler.logout(this.exchange, this.authentication).block();
+
+		this.delegate1Result.assertWasSubscribed();
+		this.delegate2Result.assertWasSubscribed();
+	}
+}