Error: resource types are not the same when composing components

[mschuwalow]

I'm trying to wrap a component that implments wasi:http/incoming-handler into a different api. The way I'm trying to accomplish this is by having two different components that will be composed with it.

1. Exports the wasi:http/types interface + some extensions. This will be composed with (2) and (3) and has otherwise no imports (except other wasi interfaces)
2. The wrapped component. This imports wasi:http/types and exports wasi:http/incoming-handler.
3. A component providing the new api. This imports wasi:http/types, wasi:http/incoming-handler, the extensions from (1) and exports the new api.

---

Problem is that when I try composing the wasm, it errors with:

❯ wac plug adapter.wasm --plug types.wasm -o adapter-plugged.wasm
error: encoding produced a component that failed validation

Caused by:
    type mismatch for import `wasi:http/[email protected]`
    type mismatch in instance export `incoming-request`
    resource types are not the same (ResourceId { globally_unique_id: 2, contextually_unique_id: 8 } vs. ResourceId { globally_unique_id: 2, contextually_unique_id: 57 }) (at offset 0x4e0399)

This error shows up both for wac plug and wac compose.

---

Wits look as follows:
Component 1:

package poc:types;

interface extensions {
    use wasi:http/[email protected].{method, scheme, status-code, incoming-request, response-outparam};

    type fields = list<tuple<string, list<u8>>>;

    type body = list<u8>;

    record body-and-trailers {
        body: body,
        trailers: option<fields>
    }

    record request {
        method: method,
        path-with-query: string,
        scheme: scheme,
        authority: string,
        headers: fields,
        body-and-trailers: option<body-and-trailers>
    }

    record response {
        status: status-code,
        body: option<body-and-trailers>
    }

    resource response-outparam-proxy {
        constructor();

        new-outparam: func() -> response-outparam;
        get-response: func() -> response;
    }

    new-wasi-http-request: func(request: request) -> incoming-request;
}

world api {
    export wasi:http/[email protected];
    export extensions
}

Component 2:

package poc:handler;

world api {
  import wasi:http/[email protected];
  export wasi:http/[email protected];
}

Component 3:

package poc:adapter;

interface adapted-api {
    use poc:types/extensions.{request, response};

    handle: func(request: request) -> response;
}

world api {
    import wasi:http/[email protected];
    import wasi:http/[email protected];
    import poc:types/extensions;

    export adapted-api;
}

---

I suspect this is a similiar error to bytecodealliance/wasm-tools#1565. This comment provided a reproduction that fails with the same error.