尽管遭到拒绝，承诺仍会兑现

Question

我正在使用 bluebird 结算方法来检查承诺的结果，无论是否有任何拒绝。在 secondMethod 我已经拒绝了承诺，但我仍然得到 isFulfilled() true.

var Promise = require('bluebird');

Promise.settle([firstMethod, secondMethod]).then(function(results){
    console.log(results[0].isFulfilled()); 
    console.log(results[1].isFulfilled()); 
   // console.log(results[1].reason());
}).catch(function(error){
    console.log(error);
});

    var firstMethod = function() {
   var promise = new Promise(function(resolve, reject){
      setTimeout(function() {
         resolve({data: '123'});
      }, 2000);
   });
   return promise;
};


var secondMethod = function() {
   var promise = new Promise(function(resolve, reject){
      setTimeout(function() {
         reject((new Error('fail')));
      }, 2000);
   });
   return promise;
};

Answer 1

很确定 isFulfilled 指的是它是否完整，无论它是 resolved 还是 rejected。

您可以使用 isRejected 之类的东西来检查承诺是否已被拒绝。

Answer 2

settle API 已弃用。请参考 github link and this for info. Use reflect API 而不是文档中指出的那样。

其次，documentation举例说明：

Using .reflect() to implement settleAll (wait until all promises in an array are either rejected or fulfilled) functionality

var promises = [getPromise(), getPromise(), getPromise()];
Promise.all(promises.map(function(promise) {
    return promise.reflect();
})).each(function(inspection) {
    if (inspection.isFulfilled()) {
        console.log("A promise in the array was fulfilled with", inspection.value());
    } else {
        console.error("A promise in the array was rejected with", inspection.reason());
    }
});

以上代码解释：

在上面的示例中，作者使用 map 遍历承诺数组，其中 returns reflect 并检查每个承诺是 isRejected 或 isFulfilled。

Answer 3

我调试了你的代码，你的函数中的代码没有被调用。您需要实际调用函数 :)

Promise.settle([firstMethod(), secondMethod()]).then(function (results) {
    console.log(results[0].isFulfilled()); // prints "true"
    console.log(results[1].isFulfilled()); // prints "false"
    console.log(results[1].reason()); // prints "fail"
}).catch(function (error) {
    console.log(error);
});

尽管遭到拒绝，承诺仍会兑现

Promise fulfilled inspite of rejection

javascript

node.js

bluebird