带有 Http 响应的 Promise 链接

Question

我正在尝试 Promise 链接，但我不太明白。我有这个练习我正在做的地方我必须做以下场景：

“你是在恶作剧办公室成员，在他的咖啡里加盐，你要通过/locate api查看他的位置，'locate'可以是以下任意一种：

response.body: 'in the office'
response.body: 'in the kitchen'

你只在他在厨房时加盐，所以如果 response.body 返回“在厨房里”，你就用/addSalt 的另一个 post api 给他的咖啡加盐。

现在这个练习中有一个名为 /run 的最终 api 端点，在满足任一条件时调用它：

/locate returns 'in the office'
/addSalt is called.

我在没有合并任何 api 或 json 的情况下尝试了以下操作（但我想这样做），它看起来像这样：

function myPromiseFunction() {
  //Change the resolved value to take a different path
  return Promise.resolve(true);
}

function conditionalChaining(value) {
  if (value.body === 'in the kitchen') {
    //do addSalt then run
    return addSalt(salt).then(run);
  } else {
    //run
    return run();
  }
}

function locate() {
  // fetch http get location, response body is either 'in his office' or 'in the kitchen'
  return Promise.resolve(response.body);
}

function addSalt(salt) {
  console.log("addSalt");
  return Promise.resolve("We added salt");
}

function run() {
  console.log("We are running");
  return Promise.resolve("Running");
}

myPromiseFunction().then(conditionalChaining).then(function() {
  console.log("All done!");
}).
catch(function(e) {

});

我不知道conditionalChaining 正在做什么，也不知道myPromiseFunction。这显然没有用，但它可以帮助概述我想要得到的东西。有什么建议吗？

我引用了这个：How to handle the if-else in promise then?

Answer 1

myPromiseFunction() 应该解析一个包含“in the office”或“in the kitchen”的对象，该对象将 conditionalChaining 的值传递给处理，并确定下一步操作。请参阅下面的示例，我已针对您的用例进行了调整。

    function locate() {
        //const msg = "in the office"; // choose either one to return, can comment the other out.
      const msg = "in the kitchen";
      var obj = {body: msg};
      return Promise.resolve(obj);
    }
    
    function addSalt(salt) {
        console.log("addSalt");
        return Promise.resolve("We added salt");
    }
    
    function run() {
        console.log("We are running");
        return Promise.resolve("Running");
    }
    
    function conditionalChaining(value) {
        if (value.body === 'in the kitchen') {
            //do addSalt then run
            return addSalt("some salt value since its undefined by u").then(run);
        } else if ( value.body === 'in the office' ) {
          console.log("hey you are in the office");
        } else {
            //run
            return run();
        }
    }
    
    // in this function, you are suppose to resolve the string "in the kitchen" or "in the office"
    // this is so that the conditionalChaining function takes in either of the string and process the next action.
    function myPromiseFunction() {
        return Promise.resolve(locate());
    }
    
    myPromiseFunction().then(conditionalChaining).then(function () {
        console.log("All done!");
    });

jsfiddle：https://jsfiddle.net/y7xrw6d0/