Fix ProxyExchange to Support bodies in delete requests (#1666)

Fixes gh-825

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

@@ -322,8 +322,8 @@ public class ProxyExchange<T> {
 	}
 
 	public 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-mvc/src/test/java/org/springframework/cloud/gateway/mvc/ProductionConfigurationTests.java

@@ -37,13 +37,16 @@ import org.springframework.cloud.gateway.mvc.ProductionConfigurationTests.TestAp
 import org.springframework.cloud.gateway.mvc.ProductionConfigurationTests.TestApplication.Bar;
 import org.springframework.cloud.gateway.mvc.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.RequestEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.util.LinkedMultiValueMap;
+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;
@@ -245,6 +248,27 @@ public class ProductionConfigurationTests {
 		assertThat(foo.getName()).isEqualTo("hello");
 	}
 
+	@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);
+	}
+
 	@Test
 	@SuppressWarnings({ "Duplicates", "unchecked" })
 	public void headers() throws Exception {
@@ -386,6 +410,21 @@ public class ProductionConfigurationTests {
 				return proxy.uri(home.toString() + "/foos").post();
 			}
 
+			@DeleteMapping("/proxy/{id}/no-body")
+			public ResponseEntity<?> deleteWithoutBody(@PathVariable Integer id,
+					ProxyExchange<?> proxy) throws Exception {
+				return proxy.uri(home.toString() + "/foos/" + id + "/no-body").delete();
+			}
+
+			@DeleteMapping("/proxy/{id}")
+			public ResponseEntity<?> deleteWithBody(@PathVariable Integer id,
+					@RequestBody Foo foo, ProxyExchange<?> proxy) throws Exception {
+				return proxy.uri(home.toString() + "/foos/" + id).body(foo)
+						.delete(response -> ResponseEntity
+								.status(response.getStatusCode())
+								.headers(response.getHeaders()).body(response.getBody()));
+			}
+
 			@GetMapping("/forward/**")
 			public void forward(ProxyExchange<?> proxy) throws Exception {
 				String path = proxy.path("/forward");
@@ -459,6 +498,17 @@ public class ProductionConfigurationTests {
 				return new Foo(id == 1 ? "foo" : custom != null ? custom : "bye");
 			}
 
+			@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));
+			}
+
 			@PostMapping("/bars")
 			public List<Bar> bars(@RequestBody List<Foo> foos,
 					@RequestHeader HttpHeaders headers) {