Function patchAppUse

packages/hono/src/shared/patchAppUse.ts:19–40

(app: Hono<E>)

 * Idempotent.
 */
export function patchAppUse<E extends Env>(app: Hono<E>): void {
  if (patchedUseInstances.has(app)) {
    DEBUG_BUILD && debug.log('[hono] app.use already patched — skipping.');
    return;
  }

  patchedUseInstances.add(app);

  app.use = new Proxy(app.use, {
    apply(target: typeof app.use, thisArg: typeof app, args: Parameters<typeof app.use>): ReturnType<typeof app.use> {
      const [first, ...rest] = args as [unknown, ...MiddlewareHandler[]];

      if (typeof first === 'string') {
        const wrappedHandlers = rest.map(handler => wrapMiddlewareWithSpan(handler));
        return Reflect.apply(target, thisArg, [first, ...wrappedHandlers]);
      }

      const allHandlers = [first as MiddlewareHandler, ...rest].map(handler => wrapMiddlewareWithSpan(handler));
      return Reflect.apply(target, thisArg, allHandlers);
    },
  });
}

/**
 * Patches HTTP method class fields (get, post, put, delete, options, patch, all) to instrument inline middleware at registration time.