如何使用默认catch和处理程序创建Promise [英] How to create a Promise with default catch and then handlers

问题描述

我正在创建一个使用koa和babel async/await的API

I'm creating an API that is using koa and babel async/await

控制器功能中的每个诺言都像这样:

Every promise in my controllers function looks like this:

async function ... {
    await Promise ... 
       .then(data => response function)
       .catch(err => err function)
}

每个promise具有完全相同的响应和错误功能.

Each promise has the exact same response and error function.

有没有办法让我用相同的then/catch自动使每个promise解析(就像promise的默认resolve函数一样).

Is there a way for me to automatically have each promise resolve with the same then/catch (like a default resolve function for the promise).

然后我的代码如下:

async function ... {
    await Promise ... 
}

并且诺言将自动解决/捕获.

and the promise would auto resolve/catch.

推荐答案

使用组成:

class MyPromise {
    constructor(executor) {
       this.promise = new Promise(executor);
       this.promise = this.promise
                          .then(defaultOnFulfilled, defaultOnReject);
    }
    then(onFulfilled, onRejected) {
       return this.promise.then(onFulfilled, onRejected);
    }
    catch(onRejected) {
       return this.promise.catch(onRejected);
    }
}

哪个会让你做:

new MyPromise((resolve, reject) => {... }).then(() => {
   // default actions have already run here
});

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