Add shortcuts for frequently used assertions

See gh-32712

spring-test/src/main/java/org/springframework/test/web/servlet/assertj/AbstractHttpServletResponseAssert.java

@@ -28,7 +28,9 @@
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.HttpStatus.Series;
+import org.springframework.http.MediaType;
 import org.springframework.test.http.HttpHeadersAssert;
+import org.springframework.test.http.MediaTypeAssert;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.function.SingletonSupplier;
@@ -48,15 +50,24 @@
 public abstract class AbstractHttpServletResponseAssert<R extends HttpServletResponse, SELF extends AbstractHttpServletResponseAssert<R, SELF, ACTUAL>, ACTUAL>
 		extends AbstractObjectAssert<SELF, ACTUAL> {
 
-	private final Supplier<AbstractIntegerAssert<?>> statusAssert;
+	private final Supplier<MediaTypeAssert> contentTypeAssertSupplier;
 
 	private final Supplier<HttpHeadersAssert> headersAssertSupplier;
 
+	private final Supplier<AbstractIntegerAssert<?>> statusAssert;
+
 
 	protected AbstractHttpServletResponseAssert(ACTUAL actual, Class<?> selfType) {
 		super(actual, selfType);
-		this.statusAssert = SingletonSupplier.of(() -> Assertions.assertThat(getResponse().getStatus()).as("HTTP status code"));
+		this.contentTypeAssertSupplier = SingletonSupplier.of(() -> new MediaTypeAssert(getResponse().getContentType()));
 		this.headersAssertSupplier = SingletonSupplier.of(() -> new HttpHeadersAssert(getHttpHeaders(getResponse())));
+		this.statusAssert = SingletonSupplier.of(() -> Assertions.assertThat(getResponse().getStatus()).as("HTTP status code"));
+	}
+
+	private static HttpHeaders getHttpHeaders(HttpServletResponse response) {
+		MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
+		response.getHeaderNames().forEach(name -> headers.put(name, new ArrayList<>(response.getHeaders(name))));
+		return new HttpHeaders(headers);
 	}
 
 	/**
@@ -67,6 +78,14 @@ protected AbstractHttpServletResponseAssert(ACTUAL actual, Class<?> selfType) {
 	 */
 	protected abstract R getResponse();
 
+	/**
+	 * Return a new {@linkplain MediaTypeAssert assertion} object that uses the
+	 * response's {@linkplain MediaType content type} as the object to test.
+	 */
+	public MediaTypeAssert contentType() {
+		return this.contentTypeAssertSupplier.get();
+	}
+
 	/**
 	 * Return a new {@linkplain HttpHeadersAssert assertion} object that uses
 	 * {@link HttpHeaders} as the object to test. The returned assertion
@@ -84,6 +103,82 @@ public HttpHeadersAssert headers() {
 		return this.headersAssertSupplier.get();
 	}
 
+	// Content-type shortcuts
+
+	/**
+	 * Verify that the response's {@code Content-Type} is equal to the given value.
+	 * @param contentType the expected content type
+	 */
+	public SELF hasContentType(MediaType contentType) {
+		contentType().isEqualTo(contentType);
+		return this.myself;
+	}
+
+	/**
+	 * Verify that the response's {@code Content-Type} is equal to the given
+	 * string representation.
+	 * @param contentType the expected content type
+	 */
+	public SELF hasContentType(String contentType) {
+		contentType().isEqualTo(contentType);
+		return this.myself;
+	}
+
+	/**
+	 * Verify that the response's {@code Content-Type} is
+	 * {@linkplain MediaType#isCompatibleWith(MediaType) compatible} with the
+	 * given value.
+	 * @param contentType the expected compatible content type
+	 */
+	public SELF hasContentTypeCompatibleWith(MediaType contentType) {
+		contentType().isCompatibleWith(contentType);
+		return this.myself;
+	}
+
+	/**
+	 * Verify that the response's {@code Content-Type} is
+	 * {@linkplain MediaType#isCompatibleWith(MediaType) compatible} with the
+	 * given string representation.
+	 * @param contentType the expected compatible content type
+	 */
+	public SELF hasContentTypeCompatibleWith(String contentType) {
+		contentType().isCompatibleWith(contentType);
+		return this.myself;
+	}
+
+	// Headers shortcuts
+
+	/**
+	 * Verify that the response contains a header with the given {@code name}.
+	 * @param name the name of an expected HTTP header
+	 */
+	public SELF containsHeader(String name) {
+		headers().containsHeader(name);
+		return this.myself;
+	}
+
+	/**
+	 * Verify that the response does not contain a header with the given {@code name}.
+	 * @param name the name of an HTTP header that should not be present
+	 */
+	public SELF doesNotContainHeader(String name) {
+		headers().doesNotContainHeader(name);
+		return this.myself;
+	}
+
+	/**
+	 * Verify that the response contains a header with the given {@code name}
+	 * and primary {@code value}.
+	 * @param name the name of an expected HTTP header
+	 * @param value the expected value of the header
+	 */
+	public SELF hasHeader(String name, String value) {
+		headers().hasValue(name, value);
+		return this.myself;
+	}
+
+	// Status
+
 	/**
 	 * Verify that the HTTP status is equal to the specified status code.
 	 * @param status the expected HTTP status code
@@ -159,10 +254,4 @@ private AbstractIntegerAssert<?> status() {
 		return this.statusAssert.get();
 	}
 
-	private static HttpHeaders getHttpHeaders(HttpServletResponse response) {
-		MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
-		response.getHeaderNames().forEach(name -> headers.put(name, new ArrayList<>(response.getHeaders(name))));
-		return new HttpHeaders(headers);
-	}
-
 }

spring-test/src/main/java/org/springframework/test/web/servlet/assertj/MvcTestResultAssert.java

@@ -30,12 +30,10 @@
 import org.assertj.core.error.BasicErrorMessageFactory;
 import org.assertj.core.internal.Failures;
 
-import org.springframework.http.MediaType;
 import org.springframework.http.converter.GenericHttpMessageConverter;
 import org.springframework.lang.Nullable;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
-import org.springframework.test.http.MediaTypeAssert;
 import org.springframework.test.web.servlet.MvcResult;
 import org.springframework.test.web.servlet.ResultHandler;
 import org.springframework.test.web.servlet.ResultMatcher;
@@ -87,14 +85,6 @@ public CookieMapAssert cookies() {
 		return new CookieMapAssert(getMvcResult().getResponse().getCookies());
 	}
 
-	/**
-	 * Return a new {@linkplain MediaTypeAssert assertion} object that uses the
-	 * response's {@linkplain MediaType content type} as the object to test.
-	 */
-	public MediaTypeAssert contentType() {
-		return new MediaTypeAssert(getMvcResult().getResponse().getContentType());
-	}
-
 	/**
 	 * Return a new {@linkplain HandlerResultAssert assertion} object that uses
 	 * the handler as the object to test. For a method invocation on a

spring-test/src/test/java/org/springframework/test/web/servlet/assertj/AbstractHttpServletResponseAssertTests.java

@@ -23,6 +23,7 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.mock.web.MockHttpServletResponse;
 
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
@@ -37,20 +38,76 @@ class AbstractHttpServletResponseAssertTests {
 	@Nested
 	class HeadersTests {
 
+		@Test
+		void containsHeader() {
+			MockHttpServletResponse response = createResponse(Map.of("n1", "v1", "n2", "v2", "n3", "v3"));
+			assertThat(response).containsHeader("n1");
+		}
+
+		@Test
+		void doesNotContainHeader() {
+			MockHttpServletResponse response = createResponse(Map.of("n1", "v1", "n2", "v2", "n3", "v3"));
+			assertThat(response).doesNotContainHeader("n4");
+		}
+
+		@Test
+		void hasHeader() {
+			MockHttpServletResponse response = createResponse(Map.of("n1", "v1", "n2", "v2", "n3", "v3"));
+			assertThat(response).hasHeader("n1", "v1");
+		}
+
 		@Test
 		void headersAreMatching() {
 			MockHttpServletResponse response = createResponse(Map.of("n1", "v1", "n2", "v2", "n3", "v3"));
 			assertThat(response).headers().containsHeaders("n1", "n2", "n3");
 		}
 
-
 		private MockHttpServletResponse createResponse(Map<String, String> headers) {
 			MockHttpServletResponse response = new MockHttpServletResponse();
 			headers.forEach(response::addHeader);
 			return response;
 		}
 	}
 
+	@Nested
+	class ContentTypeTests {
+
+		@Test
+		void contentType() {
+			MockHttpServletResponse response = createResponse("text/plain");
+			assertThat(response).hasContentType(MediaType.TEXT_PLAIN);
+		}
+
+		@Test
+		void contentTypeAndRepresentation() {
+			MockHttpServletResponse response = createResponse("text/plain");
+			assertThat(response).hasContentType("text/plain");
+		}
+
+		@Test
+		void contentTypeCompatibleWith() {
+			MockHttpServletResponse response = createResponse("application/json;charset=UTF-8");
+			assertThat(response).hasContentTypeCompatibleWith(MediaType.APPLICATION_JSON);
+		}
+
+		@Test
+		void contentTypeCompatibleWithAndStringRepresentation() {
+			MockHttpServletResponse response = createResponse("text/plain");
+			assertThat(response).hasContentTypeCompatibleWith("text/*");
+		}
+
+		@Test
+		void contentTypeCanBeAsserted() {
+			MockHttpServletResponse response = createResponse("text/plain");
+			assertThat(response).contentType().isInstanceOf(MediaType.class).isCompatibleWith("text/*").isNotNull();
+		}
+
+		private MockHttpServletResponse createResponse(String contentType) {
+			MockHttpServletResponse response = new MockHttpServletResponse();
+			response.setContentType(contentType);
+			return response;
+		}
+	}
 
 	@Nested
 	class StatusTests {

spring-test/src/test/java/org/springframework/test/web/servlet/assertj/MockMvcTesterIntegrationTests.java

@@ -138,16 +138,6 @@ public boolean preHandle(HttpServletRequest request, HttpServletResponse respons
 		}
 	}
 
-	@Nested
-	class ContentTypeTests {
-
-		@Test
-		void contentType() {
-			assertThat(perform(get("/greet"))).contentType().isCompatibleWith("text/plain");
-		}
-
-	}
-
 	@Nested
 	class StatusTests {
 
@@ -168,8 +158,8 @@ class HeadersTests {
 
 		@Test
 		void shouldAssertHeader() {
-			assertThat(perform(get("/greet"))).headers()
-					.hasValue("Content-Type", "text/plain;charset=ISO-8859-1");
+			assertThat(perform(get("/greet")))
+					.hasHeader("Content-Type", "text/plain;charset=ISO-8859-1");
 		}
 
 		@Test