WebTestClient cookie assertion support

See gh-19647

spring-test/src/main/java/org/springframework/mock/http/client/reactive/MockClientHttpResponse.java

@@ -80,7 +80,7 @@ public class MockClientHttpResponse implements ClientHttpResponse {
 	public HttpHeaders getHeaders() {
 		if (!getCookies().isEmpty() && this.headers.get(HttpHeaders.SET_COOKIE) == null) {
 			getCookies().values().stream().flatMap(Collection::stream)
-					.forEach(cookie -> getHeaders().add(HttpHeaders.SET_COOKIE, cookie.toString()));
+					.forEach(cookie -> this.headers.add(HttpHeaders.SET_COOKIE, cookie.toString()));
 		}
 		return this.headers;
 	}

spring-test/src/main/java/org/springframework/test/web/reactive/server/CookieAssertions.java

@@ -0,0 +1,220 @@
+/*
+ * Copyright 2002-2020 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
+ *
+ *      https://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.test.web.reactive.server;
+
+import java.time.Duration;
+import java.util.function.Consumer;
+
+import org.hamcrest.Matcher;
+import org.hamcrest.MatcherAssert;
+
+import org.springframework.http.ResponseCookie;
+import org.springframework.test.util.AssertionErrors;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+
+/**
+ * Assertions on cookies of the response.
+ * @author Rossen Stoyanchev
+ */
+public class CookieAssertions {
+
+	private final ExchangeResult exchangeResult;
+
+	private final WebTestClient.ResponseSpec responseSpec;
+
+
+	public CookieAssertions(ExchangeResult exchangeResult, WebTestClient.ResponseSpec responseSpec) {
+		this.exchangeResult = exchangeResult;
+		this.responseSpec = responseSpec;
+	}
+
+
+	/**
+	 * Expect a header with the given name to match the specified values.
+	 */
+	public WebTestClient.ResponseSpec valueEquals(String name, String value) {
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name);
+			AssertionErrors.assertEquals(message, value, getCookie(name).getValue());
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert the first value of the response cookie with a Hamcrest {@link Matcher}.
+	 */
+	public WebTestClient.ResponseSpec value(String name, Matcher<? super String> matcher) {
+		String value = getCookie(name).getValue();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name);
+			MatcherAssert.assertThat(message, value, matcher);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Consume the value of the response cookie.
+	 */
+	public WebTestClient.ResponseSpec value(String name, Consumer<String> consumer) {
+		String value = getCookie(name).getValue();
+		this.exchangeResult.assertWithDiagnostics(() -> consumer.accept(value));
+		return this.responseSpec;
+	}
+
+	/**
+	 * Expect that the cookie with the given name is present.
+	 */
+	public WebTestClient.ResponseSpec exists(String name) {
+		getCookie(name);
+		return this.responseSpec;
+	}
+
+	/**
+	 * Expect that the cookie with the given name is not present.
+	 */
+	public WebTestClient.ResponseSpec doesNotExist(String name) {
+		ResponseCookie cookie = this.exchangeResult.getResponseCookies().getFirst(name);
+		if (cookie != null) {
+			String message = getMessage(name) + " exists with value=[" + cookie.getValue() + "]";
+			this.exchangeResult.assertWithDiagnostics(() -> AssertionErrors.fail(message));
+		}
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's maxAge attribute.
+	 */
+	public WebTestClient.ResponseSpec maxAge(String name, Duration expected) {
+		Duration maxAge = getCookie(name).getMaxAge();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " maxAge";
+			AssertionErrors.assertEquals(message, expected, maxAge);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's maxAge attribute with a Hamcrest {@link Matcher}.
+	 */
+	public WebTestClient.ResponseSpec maxAge(String name, Matcher<? super Long> matcher) {
+		long maxAge = getCookie(name).getMaxAge().getSeconds();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " maxAge";
+			assertThat(message, maxAge, matcher);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's path attribute.
+	 */
+	public WebTestClient.ResponseSpec path(String name, String expected) {
+		String path = getCookie(name).getPath();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " path";
+			AssertionErrors.assertEquals(message, expected, path);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's path attribute with a Hamcrest {@link Matcher}.
+	 */
+	public WebTestClient.ResponseSpec path(String name, Matcher<? super String> matcher) {
+		String path = getCookie(name).getPath();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " path";
+			assertThat(message, path, matcher);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's domain attribute.
+	 */
+	public WebTestClient.ResponseSpec domain(String name, String expected) {
+		String path = getCookie(name).getDomain();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " domain";
+			AssertionErrors.assertEquals(message, expected, path);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's domain attribute with a Hamcrest {@link Matcher}.
+	 */
+	public WebTestClient.ResponseSpec domain(String name, Matcher<? super String> matcher) {
+		String domain = getCookie(name).getDomain();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " domain";
+			assertThat(message, domain, matcher);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's secure attribute.
+	 */
+	public WebTestClient.ResponseSpec secure(String name, boolean expected) {
+		boolean isSecure = getCookie(name).isSecure();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " secure";
+			AssertionErrors.assertEquals(message, expected, isSecure);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's httpOnly attribute.
+	 */
+	public WebTestClient.ResponseSpec httpOnly(String name, boolean expected) {
+		boolean isHttpOnly = getCookie(name).isHttpOnly();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " secure";
+			AssertionErrors.assertEquals(message, expected, isHttpOnly);
+		});
+		return this.responseSpec;
+	}
+
+	/**
+	 * Assert a cookie's sameSite attribute.
+	 */
+	public WebTestClient.ResponseSpec sameSite(String name, String expected) {
+		String sameSite = getCookie(name).getSameSite();
+		this.exchangeResult.assertWithDiagnostics(() -> {
+			String message = getMessage(name) + " secure";
+			AssertionErrors.assertEquals(message, expected, sameSite);
+		});
+		return this.responseSpec;
+	}
+
+
+	private ResponseCookie getCookie(String name) {
+		ResponseCookie cookie = this.exchangeResult.getResponseCookies().getFirst(name);
+		if (cookie == null) {
+			String message = "No cookie with name '" + name + "'";
+			this.exchangeResult.assertWithDiagnostics(() -> AssertionErrors.fail(message));
+		}
+		return cookie;
+	}
+
+	private String getMessage(String cookie) {
+		return "Response cookie '" + cookie + "'";
+	}
+
+}

spring-test/src/main/java/org/springframework/test/web/reactive/server/DefaultWebTestClient.java

@@ -337,6 +337,11 @@ class DefaultWebTestClient implements WebTestClient {
 			return new HeaderAssertions(this.exchangeResult, this);
 		}
 
+		@Override
+		public CookieAssertions expectCookie() {
+			return new CookieAssertions(this.exchangeResult, this);
+		}
+
 		@Override
 		public <B> BodySpec<B, ?> expectBody(Class<B> bodyType) {
 			B body = this.response.bodyToMono(bodyType).block(this.timeout);

spring-test/src/main/java/org/springframework/test/web/reactive/server/WebTestClient.java

@@ -764,6 +764,12 @@ public interface WebTestClient {
 		 */
 		HeaderAssertions expectHeader();
 
+		/**
+		 * Assertions on the cookies of the response.
+		 * @since 5.3
+		 */
+		CookieAssertions expectCookie();
+
 		/**
 		 * Consume and decode the response body to a single object of type
 		 * {@code <B>} and then apply assertions.