任何想法如何实现所有路由可以使用的交易中间件？

Question

这是我拥有的代码。

import mongoose from 'mongoose';

const session = await mongoose.startSession();

session.startTransaction();

export default async function transactionMiddleware(req, res, next) {
    try {
        await session.withTransaction(async () => {
            await next();
        });
    } catch (error) {
        await session.abortTransaction();
        session.endSession();
        return res.status(500).json({message: 'Something went wrong.'});
    }
    await session.commitTransaction();
    session.endSession();
};

这就是我在app.js文件中使用的方式。 我的问题是，当我导入此中间件时，它不会编译。我希望编译。

import transactionMiddleware from './src/middlewares/transactionMiddleware.js'; 像这样崩溃了

如果您的目的是创建可重复使用的代码来处理您的交易，则可能应该使用包装器函数。

以将其作为参数以参数执行的代码的函数：

const transactionWrapper = (callback) => {
    const session = await mongoose.startSession();
    try {
        await session.withTransaction(async () => {
            await callback();
        });
        await session.commitTransaction();
        session.endSession();
    } catch (err) {
        await session.abortTransaction();
        session.endSession();
        throw err;
    }
}

示例用法：

Answer 1

如果有帮助，我这样做了：

import { Request, Response, NextFunction } from 'express'
import mongoose from 'mongoose'

/**
 * Middleware to manage MongoDB sessions within each request lifecycle.
 * This middleware initializes a MongoDB session and attaches it to the `req` object as `req.session`.
 * It ensures the session is closed after the response is sent to the client by listening to the `finish` event of the response object.
 * 
 * @param {Request} req - The Express request object, augmented with the session object.
 * @param {Response} res - The Express response object, used to listen for the `finish` event to close the session.
 * @param {NextFunction} next - The callback function to continue processing the middleware stack.
 * 
 * Usage:
 * The session is accessible via `req.session` in subsequent middleware and route handlers.
 * 
 * Example:
 * app.use(sessionMiddleware)
 */
export async function sessionMiddleware(req: Request, res: Response, next: NextFunction) {
  const session = await mongoose.startSession()
  req.session = session
  try {
    await req.session.startTransaction()
    res.on('finish', async () => {
      if (res.statusCode >= 200 && res.statusCode < 300) {
        await req.session.commitTransaction()
      } else {
        await req.session.abortTransaction()
      }
      await req.session.endSession()
    })

    next()
  } catch (error) {
    await req.session.abortTransaction()
    await req.session.endSession()
    next(error)
  }
}

export default sessionMiddleware