[Rust Server] Flag responses as must use (#5559)

* [Rust Server] Flag responses as must use if there is more than a single option
* Update samples

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java

@@ -716,6 +716,12 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         op.vendorExtensions.put("PATH_ID", pathId);
         op.vendorExtensions.put("hasPathParams", hasPathParams);
         op.vendorExtensions.put("HttpMethod", op.httpMethod.toUpperCase(Locale.ROOT));
+
+        if (!op.vendorExtensions.containsKey("x-mustUseResponse")) {
+          // If there's more than one response, than by default the user must explicitly handle them
+          op.vendorExtensions.put("x-mustUseResponse", op.responses.size() > 1);
+        }
+
         for (CodegenParameter param : op.allParams) {
             processParam(param, op);
         }

modules/openapi-generator/src/main/resources/rust-server/response.mustache

@@ -1,4 +1,7 @@
 #[derive(Debug, PartialEq)]
+{{#vendorExtensions.x-mustUseResponse}}
+#[must_use]
+{{/vendorExtensions.x-mustUseResponse}}
 pub enum {{{operationId}}}Response {
 {{#responses}}
   {{#message}}

samples/server/petstore/rust-server/output/openapi-v3/src/lib.rs

@@ -93,6 +93,7 @@ pub enum MergePatchJsonGetResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum MultigetGetResponse {
     /// JSON rsp
     JSONRsp
@@ -155,6 +156,7 @@ pub enum RequiredOctetStreamPutResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum ResponsesWithHeadersGetResponse {
     /// Success
     Success
@@ -173,6 +175,7 @@ pub enum ResponsesWithHeadersGetResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum Rfc7807GetResponse {
     /// OK
     OK
@@ -201,6 +204,7 @@ pub enum UuidGetResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum XmlExtraPostResponse {
     /// OK
     OK
@@ -210,6 +214,7 @@ pub enum XmlExtraPostResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum XmlOtherPostResponse {
     /// OK
     OK
@@ -219,6 +224,7 @@ pub enum XmlOtherPostResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum XmlOtherPutResponse {
     /// OK
     OK
@@ -228,6 +234,7 @@ pub enum XmlOtherPutResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum XmlPostResponse {
     /// OK
     OK
@@ -237,6 +244,7 @@ pub enum XmlPostResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum XmlPutResponse {
     /// OK
     OK

samples/server/petstore/rust-server/output/petstore-with-fake-endpoints-models-for-testing/src/lib.rs

@@ -138,6 +138,7 @@ pub enum TestClientModelResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum TestEndpointParametersResponse {
     /// Invalid username supplied
     InvalidUsernameSupplied
@@ -147,6 +148,7 @@ pub enum TestEndpointParametersResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum TestEnumParametersResponse {
     /// Invalid request
     InvalidRequest
@@ -187,6 +189,7 @@ pub enum DeletePetResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum FindPetsByStatusResponse {
     /// successful operation
     SuccessfulOperation
@@ -197,6 +200,7 @@ pub enum FindPetsByStatusResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum FindPetsByTagsResponse {
     /// successful operation
     SuccessfulOperation
@@ -207,6 +211,7 @@ pub enum FindPetsByTagsResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum GetPetByIdResponse {
     /// successful operation
     SuccessfulOperation
@@ -220,6 +225,7 @@ pub enum GetPetByIdResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum UpdatePetResponse {
     /// Invalid ID supplied
     InvalidIDSupplied
@@ -245,6 +251,7 @@ pub enum UploadFileResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum DeleteOrderResponse {
     /// Invalid ID supplied
     InvalidIDSupplied
@@ -261,6 +268,7 @@ pub enum GetInventoryResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum GetOrderByIdResponse {
     /// successful operation
     SuccessfulOperation
@@ -274,6 +282,7 @@ pub enum GetOrderByIdResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum PlaceOrderResponse {
     /// successful operation
     SuccessfulOperation
@@ -302,6 +311,7 @@ pub enum CreateUsersWithListInputResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum DeleteUserResponse {
     /// Invalid username supplied
     InvalidUsernameSupplied
@@ -311,6 +321,7 @@ pub enum DeleteUserResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum GetUserByNameResponse {
     /// successful operation
     SuccessfulOperation
@@ -324,6 +335,7 @@ pub enum GetUserByNameResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum LoginUserResponse {
     /// successful operation
     SuccessfulOperation
@@ -344,6 +356,7 @@ pub enum LogoutUserResponse {
 }
 
 #[derive(Debug, PartialEq)]
+#[must_use]
 pub enum UpdateUserResponse {
     /// Invalid user supplied
     InvalidUserSupplied