René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"strict-server: any-typed response bodies generate a method on an interface type, which does not compile","articleBody":"Found during the review of #2522; pre-existing on `main` and independent of that PR.\n\n## Problem\n\nUnder `strict-server`, a JSON response body whose schema lowers to `any` generates a defined type with an interface underlying type, plus a value-receiver method on it:\n\n```go\ntype GetThing200JSONResponse any\n\nfunc (response GetThing200JSONResponse) VisitGetThingResponse(w http.ResponseWriter) error {\n```\n\nGo forbids methods on types whose underlying type is a pointer or interface, so the output does not compile:\n\n```\ninvalid receiver type GetThing200JSONResponse (pointer or interface type)\n```\n\n## Reproduction\n\nVerified on `main` with:\n\n```yaml\npaths:\n  /things:\n    get:\n      operationId: getThing\n      responses:\n        \"200\":\n          description: ok\n          content:\n            application/json:\n              schema: {}\n```\n\nand config `generate: { models: true, std-http-server: true, strict-server: true }`. The same happens for `type: \"null\"` (#2430) and, once #2522 lands, for multi-type unions (`type: [string, number]`) — every schema shape that lowers to `any`.\n\n## Notes\n\n- Non-strict servers are unaffected; only the strict envelope needs a method on the response type.\n- Since this output has never compiled, there are no existing users of the current shape — the fix is free to choose the right one. The obvious candidate is wrapping the body in a struct for interface-underlying response types (e.g. `type GetThing200JSONResponse struct { Body any }`, with the visitor marshaling `response.Body`), mirroring how strict response envelopes with headers already wrap. Alternatively the generator could error on this combination with a pointer at the workaround (`x-go-type` to a concrete type), but generating something that works seems strictly better.\n","author":{"url":"https://github.com/mromaszewicz","@type":"Person","name":"mromaszewicz"},"datePublished":"2026-08-16T14:27:29Z","url":"https://github.com/oapi-codegen/oapi-codegen/issues/2525"}