有没有办法包装等待/异步try / catch块到每个功能？ [英] Is there a way to wrap an await/async try/catch block to every function?

问题描述

所以我正在使用express.js并查看使用async / await与节点7.有没有办法，我仍然可以捕获错误，但摆脱try / catch块？也许函数包装器？我不知道这将如何实际执行该函数的代码，并调用 next（err）。

So i'm using express.js and looking into using async/await with node 7. Is there a way that I can still catch errors but get rid of the try/catch block? Perhaps a function wrapper? I'm not sure how this would actually execute the function's code and also call next(err).

exports.index = async function(req, res, next) {
  try {
    let user = await User.findOne().exec();

    res.status(200).json(user);
  } catch(err) {
    next(err);
  }
}

这样的东西...？

function example() {
   // Implements try/catch block and then handles error.
}

exports.index = async example(req, res, next) {
  let user = await User.findOne().exec();
  res.status(200).json(user);
}

编辑：

更类似的东西：

var wrapper = function(f) {
    return function() {
        try {
            f.apply(this, arguments);
        } catch(e) {
            customErrorHandler(e)
        }
    }
}

这将以某种方式处理try / catch块但不起作用：

This would somehow handle the try/catch block but doesn't work:

exports.index = wrapper(async example(req, res, next) {
  let user = await User.findOne().exec();
  res.status(200).json(user);
});

请参阅有没有办法为Javascript中的每个函数添加try-catch？为非异步示例。

See Is there a way to add try-catch to every function in Javascript? for the non-async example.

推荐答案

是的，您可以轻松地为异步函数编写这样的包装器 - 只需使用 async / await ：

Yes, you can easily write such a wrapper for asynchronous functions as well - just use async/await:

function wrapper(f) {
    return async function() {
//         ^^^^^
        try {
            return await f.apply(this, arguments);
//                 ^^^^^
        } catch(e) {
            customErrorHandler(e)
        }
    }
}

或者您直接使用承诺，就像在这个例子中，更适合表达（特别是参数的数量）： p>

Or you use promises directly, like in this example that is more tailored to express (especially with the number of parameters):

function promiseWrapper(fn) {
    return (req, res, next) => {
         fn(req, res).catch(next);
    };
}

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