Adds Support for webflux ProxyExchange to use body in delete method

Fixes gh-2103
Fixes gh-2132

spring-cloud-gateway-webflux/src/main/java/org/springframework/cloud/gateway/webflux/ProxyExchange.java

@@ -287,8 +287,8 @@ public class ProxyExchange<T> {
 	}
 
 	public Mono<ResponseEntity<T>> delete() {
-		RequestEntity<Void> requestEntity = headers(
-				(BodyBuilder) RequestEntity.delete(uri)).build();
+		RequestEntity<Object> requestEntity = headers(
+				(BodyBuilder) RequestEntity.delete(uri)).body(body());
 		return exchange(requestEntity);
 	}
 

spring-cloud-gateway-webflux/src/test/java/org/springframework/cloud/gateway/webflux/ProductionConfigurationTests.java

@@ -39,7 +39,9 @@ import org.springframework.cloud.gateway.webflux.ProductionConfigurationTests.Te
 import org.springframework.cloud.gateway.webflux.ProductionConfigurationTests.TestApplication.Bar;
 import org.springframework.cloud.gateway.webflux.ProductionConfigurationTests.TestApplication.Foo;
 import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.RequestEntity;
@@ -47,6 +49,7 @@ import org.springframework.http.ResponseEntity;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -225,6 +228,24 @@ public class ProductionConfigurationTests {
 		assertThat(headers.get("forwarded").get(0)).isEqualTo("host=localhost:" + port);
 	}
 
+	@Test
+	public void deleteWithoutBody() throws Exception {
+		ResponseEntity<Void> deleteResponse = rest.exchange("/proxy/{id}/no-body", HttpMethod.DELETE, null, Void.TYPE,
+				Collections.singletonMap("id", "123"));
+		assertThat(deleteResponse.getStatusCode()).isEqualTo(HttpStatus.OK);
+	}
+
+	@Test
+	public void deleteWithBody() throws Exception {
+		Foo foo = new Foo("to-be-deleted");
+		ParameterizedTypeReference<Map<String, Foo>> returnType = new ParameterizedTypeReference<Map<String, Foo>>() {
+		};
+		ResponseEntity<Map<String, Foo>> deleteResponse = rest.exchange("/proxy/{id}", HttpMethod.DELETE,
+				new HttpEntity<Foo>(foo), returnType, Collections.singletonMap("id", "123"));
+		assertThat(deleteResponse.getStatusCode()).isEqualTo(HttpStatus.OK);
+		assertThat(deleteResponse.getBody().get("deleted")).isEqualToComparingFieldByField(foo);
+	}
+
 	@SpringBootApplication
 	static class TestApplication {
 
@@ -360,6 +381,19 @@ public class ProductionConfigurationTests {
 						.forward(this::first);
 			}
 
+			@DeleteMapping("/proxy/{id}/no-body")
+			public Mono<ResponseEntity<Object>> deleteWithoutBody(@PathVariable Integer id, ProxyExchange<Object> proxy)
+					throws Exception {
+				return proxy.uri(home.toString() + "/foos/" + id + "/no-body").delete();
+			}
+
+			@DeleteMapping("/proxy/{id}")
+			public Mono<ResponseEntity<Object>> deleteWithBody(@PathVariable Integer id, @RequestBody Foo foo,
+					ProxyExchange<Object> proxy) throws Exception {
+				return proxy.uri(home.toString() + "/foos/" + id).body(foo).delete(response -> ResponseEntity
+						.status(response.getStatusCode()).headers(response.getHeaders()).body(response.getBody()));
+			}
+
 		}
 
 		@RestController
@@ -391,6 +425,16 @@ public class ProductionConfigurationTests {
 				return headers;
 			}
 
+			@DeleteMapping("/foos/{id}/no-body")
+			public ResponseEntity<?> deleteFoo(@PathVariable Integer id) {
+				return ResponseEntity.ok().build();
+			}
+
+			@DeleteMapping("/foos/{id}")
+			public ResponseEntity<?> deleteFoo(@PathVariable Integer id, @RequestBody Foo foo) {
+				return ResponseEntity.ok().body(Collections.singletonMap("deleted", foo));
+			}
+
 		}
 
 		@JsonIgnoreProperties(ignoreUnknown = true)