Add a method to RestTestClient API that provides a JsonContentAssert

spring-test/src/main/java/org/springframework/test/web/servlet/client/DefaultRestTestClient.java

@@ -40,9 +40,12 @@
 import org.springframework.http.client.ClientHttpRequestExecution;
 import org.springframework.http.client.ClientHttpRequestInterceptor;
 import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.test.json.AbstractJsonContentAssert;
 import org.springframework.test.json.JsonAssert;
 import org.springframework.test.json.JsonComparator;
 import org.springframework.test.json.JsonCompareMode;
+import org.springframework.test.json.JsonContent;
+import org.springframework.test.json.JsonContentAssert;
 import org.springframework.test.util.AssertionErrors;
 import org.springframework.test.util.ExceptionCollector;
 import org.springframework.test.util.XmlExpectationsHelper;
@@ -490,6 +493,15 @@ public BodyContentSpec consumeWith(Consumer<EntityExchangeResult<byte[]>> consum
 			return this;
 		}
 
+		@Override
+		public BodyContentSpec consumeWithJsonAssert(Consumer<AbstractJsonContentAssert<?>> jsonAssertConsumer) {
+			this.result.assertWithDiagnostics(() -> {
+				JsonContentAssert jsonContentAssert = new JsonContent(getBodyAsString()).assertThat();
+				jsonAssertConsumer.accept(jsonContentAssert);
+			});
+			return this;
+		}
+
 		@Override
 		public EntityExchangeResult<byte[]> returnResult() {
 			return this.result;

spring-test/src/main/java/org/springframework/test/web/servlet/client/RestTestClient.java

@@ -34,6 +34,7 @@
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.ClientHttpRequestInterceptor;
 import org.springframework.http.converter.HttpMessageConverters;
+import org.springframework.test.json.AbstractJsonContentAssert;
 import org.springframework.test.json.JsonComparator;
 import org.springframework.test.json.JsonCompareMode;
 import org.springframework.test.json.JsonComparison;
@@ -810,6 +811,27 @@ default XpathAssertions xpath(String expression, Object... args) {
 		 */
 		BodyContentSpec consumeWith(Consumer<EntityExchangeResult<byte[]>> consumer);
 
+		/**
+		 * Assert the response body content with the given {@link Consumer}.
+		 * This consumer provides a {@link AbstractJsonContentAssert} that supports
+		 * making fine-grained assertions about the JSON response body, e.g.
+		 * <pre>
+		 * {@code
+		 * restTestClient.get().uri("/test")
+		 *     .exchangeSuccessfully()
+		 *     .expectBody()
+		 *     .consumeWithJsonAssert(jsonContentAssert -> {
+		 *	       jsonContentAssert.extractingPath("$.users")
+		 *		       .asArray().singleElement()
+		 *			   .extracting("id", "name", "email")
+		 *			   .containsExactly(123, "John Doe", "[email protected]");
+		 *	   });
+		 * }
+		 * </pre>
+		 * @param jsonAssertConsumer the consumer for the response body
+		 */
+		BodyContentSpec consumeWithJsonAssert(Consumer<AbstractJsonContentAssert<?>> jsonAssertConsumer);
+
 		/**
 		 * Exit the chained API and return an {@code ExchangeResult} with the
 		 * raw response content.

spring-test/src/test/java/org/springframework/test/web/servlet/client/RestTestClientTests.java

@@ -287,6 +287,19 @@ void testExpectCookie() {
 					.exchange()
 					.expectCookie().value("session", Matchers.equalTo("abc"));
 		}
+
+		@Test
+		void testConsumeWithJsonAssert() {
+			var bodyContentSpec = RestTestClientTests.this.client.get().uri("/test")
+				.exchangeSuccessfully()
+				.expectBody()
+				.consumeWithJsonAssert(jsonContentAssert -> jsonContentAssert
+					.hasPath("method")
+					.hasPathSatisfying("uri", uri -> assertThat(uri).isEqualTo("/test"))
+					.extractingPath("headers").asMap().hasSize(2)
+				);
+			assertThat(bodyContentSpec).isNotNull();
+		}
 	}