[dart2] Include request body on DELETE call (#10100)

* Include request body on DELETE call

This change updates the generated `ApiClient` to include the request body on DELETE calls. [Per the RFC on page 2][1], DELETE calls are allowed to have a request body, even though the behavior may be undefined. I've not come across many APIs that use this behavior but there are a few, in particular the [Ory Kratos API][2] does so, not forwarding the body prevents such an API from being used. An API spec that does not define a request body should continue to function as expected.

[1] https://datatracker.ietf.org/doc/html/rfc7231#section-4.3.5
[2] https://www.ory.sh/kratos/docs/reference/api/#operation/submitSelfServiceLogoutFlowWithoutBrowser

* Samples generated with dart2 template change

modules/openapi-generator/src/main/resources/dart2/api_client.mustache

@@ -127,7 +127,7 @@ class ApiClient {
       switch(method) {
         case 'POST': return await _client.post(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PUT': return await _client.put(uri, headers: nullableHeaderParams, body: msgBody,);
-        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams,);
+        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PATCH': return await _client.patch(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'HEAD': return await _client.head(uri, headers: nullableHeaderParams,);
         case 'GET': return await _client.get(uri, headers: nullableHeaderParams,);

samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart

@@ -120,7 +120,7 @@ class ApiClient {
       switch(method) {
         case 'POST': return await _client.post(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PUT': return await _client.put(uri, headers: nullableHeaderParams, body: msgBody,);
-        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams,);
+        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PATCH': return await _client.patch(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'HEAD': return await _client.head(uri, headers: nullableHeaderParams,);
         case 'GET': return await _client.get(uri, headers: nullableHeaderParams,);

samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart

@@ -123,7 +123,7 @@ class ApiClient {
       switch(method) {
         case 'POST': return await _client.post(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PUT': return await _client.put(uri, headers: nullableHeaderParams, body: msgBody,);
-        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams,);
+        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PATCH': return await _client.patch(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'HEAD': return await _client.head(uri, headers: nullableHeaderParams,);
         case 'GET': return await _client.get(uri, headers: nullableHeaderParams,);

samples/openapi3/client/petstore/dart2/petstore_json_serializable_client_lib_fake/lib/api_client.dart

@@ -123,7 +123,7 @@ class ApiClient {
       switch(method) {
         case 'POST': return await _client.post(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PUT': return await _client.put(uri, headers: nullableHeaderParams, body: msgBody,);
-        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams,);
+        case 'DELETE': return await _client.delete(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'PATCH': return await _client.patch(uri, headers: nullableHeaderParams, body: msgBody,);
         case 'HEAD': return await _client.head(uri, headers: nullableHeaderParams,);
         case 'GET': return await _client.get(uri, headers: nullableHeaderParams,);