René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"strict-server: a form response reached through $ref is encoded under an empty field name","articleBody":"## Problem\n\nUnder `strict-server`, an operation that reaches a `components/responses` entry through `$ref` (fixed status code, no headers) embeds the reusable envelope in its own response type:\n\n```go\ntype GetThing200FormdataResponse struct{ ThingFormdataResponse }\n```\n\nFor `application/x-www-form-urlencoded`, the visitor passes that wrapper to `runtime.MarshalForm`:\n\n```go\nform, err := runtime.MarshalForm(response, nil)\n```\n\nThe embedded field has no `form` or `json` tag, so `MarshalForm` writes its fields under an empty name. A body of `{value: \"x\"}` goes on the wire as `%5Bvalue%5D=x` (`[value]=x`) instead of `value=x`. The JSON path already handles this case by encoding the embedded envelope (`response.ThingJSONResponse`); the form path does not.\n\nFound while reviewing #2514. It reproduces on `main`, in every strict flavor (std-http, chi, gorilla, echo, echo5, gin, fiber, fiber-v3, iris), and for cross-package `$ref`s through `import-mapping` too.\n\n## Reproduction\n\n```yaml\nopenapi: \"3.0.3\"\ninfo: {title: t, version: \"1\"}\npaths:\n  /thing:\n    get:\n      operationId: getThing\n      responses:\n        \"200\":\n          $ref: \"#/components/responses/Thing\"\ncomponents:\n  schemas:\n    Example:\n      type: object\n      properties:\n        value: {type: string}\n  responses:\n    Thing:\n      description: ok\n      content:\n        application/x-www-form-urlencoded:\n          schema:\n            $ref: \"#/components/schemas/Example\"\n```\n\nConfig: `generate: { models: true, std-http-server: true, strict-server: true }`.\n\nReturn `GetThing200FormdataResponse{ThingFormdataResponse: ThingFormdataResponse(Example{Value: &v})}` with `v := \"x\"`:\n\n- Observed body: `%5Bvalue%5D=x`\n- Expected body: `value=x`, which is what the same response declared inline produces.\n\n## Notes\n\n- Only form responses are affected. Text and multipart `$ref` responses are redeclared as the operation's type rather than embedded, and header-bearing or non-fixed-status responses already marshal `response.Body`.\n- The generated output has never produced a correct body, so fixing it doesn't change any output that works today.\n","author":{"url":"https://github.com/mromaszewicz","@type":"Person","name":"mromaszewicz"},"datePublished":"2026-09-27T22:40:11Z","url":"https://github.com/oapi-codegen/oapi-codegen/issues/2586"}