Function wrapServerTarget

packages/capnweb-validate/src/internal/core.ts:676–742

(
  target: T,
  validator: ServiceValidator
)

}

export function wrapServerTarget<T extends object>(
  target: T,
  validator: ServiceValidator
): T {
  return new Proxy(target, {
    get(t, prop) {
      if (typeof prop !== "string") {
        // Symbol-keyed members (Symbol.dispose etc.): forward bound to `t`.
        let orig = Reflect.get(t, prop, t);
        return typeof orig === "function" ? orig.bind(t) : orig;
      }
      let methodSpec = own(validator.methods, prop);
      if (!methodSpec) {
        // Infra / platform hook: forward the real member (read or bound).
        if (canPassThrough(prop, validator, "server")) {
          let orig = Reflect.get(t, prop, t);
          return typeof orig === "function" ? orig.bind(t) : orig;
        }
        // Outside the surface: refuse a real member without invoking it (a
        // getter would otherwise run and leak); an absent prop reads undefined.
        let desc = exposedDescriptor(t, prop);
        if (!desc) return undefined;
        return typeof desc.value === "function"
          ? (..._args: unknown[]): never =>
              missingMethod(validator.serviceName, prop)
          : missingMethod(validator.serviceName, prop);
      }
      // `t` as receiver so a declared getter can read private state.
      let orig = Reflect.get(t, prop, t);
      if (isWrappedMethod(orig)) {
        // Already wrapped in place by @validateRpc() on the class; don't
        // validate twice.
        return (orig as (...a: unknown[]) => unknown).bind(t);
      }
      if (!isUncheckedMethod(methodSpec) && methodSpec.isGetter) {
        return validateReturn(
          orig,
          methodSpec.returns,
          [validator.serviceName, prop],
          "server",
          validator.mode ?? "throw"
        );
      }
      if (typeof orig !== "function") return orig;
      let mode = validator.mode ?? "throw";
      return function wrapped(this: unknown, ...args: unknown[]): unknown {
        if (isUncheckedMethod(methodSpec)) {
          return Reflect.apply(orig as (...a: unknown[]) => unknown, t, args);
        }
        checkArgs(mode, args, methodSpec, validator.serviceName, prop);
        let wrappedArgs = wrapArgs(args, methodSpec, validator.serviceName, prop);
        let result = Reflect.apply(
          orig as (...a: unknown[]) => unknown,
          t,
          wrappedArgs
        );
        return validateReturn(
          result,