Promise All 在第一个 Promise 之后卡住了

Question

我有 5 个承诺等待使用 Promise.All

执行

GenerateWeekWorkPlan = (.....) => {
    return new Promise(async (resolve, reject) => {

        // Some logic 

        // retVal = ... DB Manipulation ... 

          if (retVal !== null) {             
              resolve({
                status: 200,
                msg: "Successfully created ..."
              });
            } else {              
              reject({
                status: 400,
                msg: "Failed to create ..."
              });
            }

    }

}

const promiseWeek1 = this.GenerateWeekWorkPlan(.....);
const promiseWeek2 = this.GenerateWeekWorkPlan(.....);
const promiseWeek3 = this.GenerateWeekWorkPlan(.....);
const promiseWeek4 = this.GenerateWeekWorkPlan(.....);
const promiseWeek5 = this.GenerateWeekWorkPlan(.....);

Promise.all(
      promiseWeek1,
      promiseWeek2,
      promiseWeek3,
      promiseWeek4,
      promiseWeek5
    )
      .then(success => console.log(success))
      .catch(failed => console.log(failed));

代码只运行了第一个promise，然后卡住了。为什么不继续下一个承诺 (2-3-4-5) ？

编辑：

GenerateWeekWorkPlan = (weekNumber, packageId, arrayOfTargets) => {
    return new Promise(async (resolve, reject) => {
      // Get all the raw data from Leads collection that is not Duplicated
      console.log("GenerateWeekWorkPlan ...");
      try {
        // 1. Get leads by package id and take all those which are not duplicated
        const leads1 = await Leads.find({
          Duplicate: false,
          PackageId: packageId
        })
          .lean()
          .exec(async (err, leads) => {
            // docs are plain javascript objects instead of model instances



            const oneWeekWorkPlan = arrayOfTargets.map(target => {
              return leads.map(lead => ({
                        .... 
              }));
            });

            console.log("--------Insert Many----------");
            const flatted = oneWeekWorkPlan.flat();
            console.log(flatted);

            const retVal = await WeekPlangs.insertMany(flatted);
            console.log("--------Done Insert Many----------");
            if (retVal !== null) {
              console.log("retVal" + retVal);
              resolve({
                status: 200,
                msg: "Successfully created documents"
              });
            } else {
              console.log("Nothing inside retVal" + retVal);
              reject({
                status: 400,
                msg: "Failed to create documents"
              });
            }
          });
      } catch (err) {
        console.error(err.message);
        reject({
          status: 400,
          msg: "Failed to create documents"
        });
      }
    });
  };
};

Answer 1

! It seems you are using it so that you can call resolve and reject from the asynchronous exec() callback - but really you shouldn't have used that callback in the first place. You would want to promisify 调用和 await 它，或者在 MongoDB 的情况下，您需要做的就是放弃回调以取回承诺。使 GenerateWeekWorkPlan 本身成为 async 函数，以便它 returns 成为一个承诺：

async function GenerateWeekWorkPlan(weekNumber, packageId, arrayOfTargets) {
  // Get all the raw data from Leads collection that is not Duplicated
  console.log("GenerateWeekWorkPlan ...");
  try {
    // 1. Get leads by package id and take all those which are not duplicated
    const leads = await Leads.find({
      Duplicate: false,
      PackageId: packageId
    }).lean();
    // docs are plain javascript objects instead of model instances
    const oneWeekWorkPlan = arrayOfTargets.flatMap(target => {
      return leads.map(lead => ({
        …
      }));
    });

    console.log("--------Insert Many----------");
    console.log(oneWeekWorkPlan);
    const retVal = await WeekPlangs.insertMany(oneWeekWorkPlan);
    console.log("--------Done Insert Many----------");
    if (retVal !== null) {
      console.log("retVal" + retVal);
      return {
        status: 200,
        msg: "Successfully created documents"
      };
    } else {
      console.log("Nothing inside retVal" + retVal);
      throw {
        status: 400,
        msg: "Failed to create documents"
      };
    }
  } catch (err) {
    console.error(err.message);
    throw {
      status: 400,
      msg: "Failed to create documents"
    };
  }
}

Promise All 在第一个 Promise 之后卡住了

Promise All stuck after first Promise

javascript

node.js

promise

es6-promise