pipeline-exec.ts

const execute: Pipe<T>["execute"] = async (context) => {
    let prevIndex = -1;

    /**
     * Programatically go through each middleware and apply it to context before
     * either moving on to the next middleware, or returning the final context
     * object.
     * @param index The current count of middleware executions.
     * @param context The context object to send through the
     * middleware pipeline.
     */
    const handler = async (index: number, context: T): Promise<void | T> => {
      if (index === prevIndex) {
        throw new Error("next() already called.");
      }

      if (index === stack.length) return context;

      prevIndex = index;

      const middleware = stack[index];

      if (middleware) {
        await middleware(context, () => handler(index + 1, context));
      }
    };
    const response = await handler(0, context);
    if (response) return response;
};