检索到所有数据后，如何在内部使用 foreach 循环解决嵌套承诺？

Question

I have one big promise in my function and inside I make 2 calls. First one to get the members from the organization. Then I iterate over it and get for each member the details + fill it into an array. I only want to resolve at the end, once I have detail data of each member. I do this by comparing the lengths of the 2 arrays. The code below works, but how can I split this or write it in a better way?

export const getTeamMembers = (firebaseContext, user) => {
  const { activeOrganization } = user;

  return new Promise((resolve, reject) => {
    firebaseContext.db
      .collection("organizations")
      .doc(activeOrganization)
      .get()
      .then((snapshot) => {
        if (!snapshot.empty) {
          const members = snapshot.data().members;
          const memberProfiles = [];

          members.forEach((m) => {
            firebaseContext.db
              .collection("users")
              .doc(m.uid)
              .get()
              .then((snapshot) => {
                const profile = snapshot.data();
                memberProfiles.push(profile);
                console.log("person added");
                console.log(memberProfiles);

                if (members.length === memberProfiles.length) {
                  resolve(memberProfiles);
                }
              })
              .catch((err) => reject(err));
          });
        } else {
          reject([]);
        }
      })
      .catch((err) => reject(err));
  });
};

Answer 1

I would recommend using async/await syntax to clean this up. Also, you can map your code to an array of promises and await all of them rather than doing the check in a forEach :

export const getTeamMembers = async (firebaseContext, user) => {
  try {
    const { activeOrganization } = user;

    const snapshot = firebaseContext.db
      .collection("organizations")
      .doc(activeOrganization)
      .get();

    const members = snapshot.data().members;
    const memberPromises = members.map(m => {
      return firebaseContext.db
        .collection("users")
        .doc(m.uid)
        .get();
    });
    return (await Promise.all(memberPromises)).map(s => s.data());
  } catch (e) {
    // throw some error to cause promise to reject
  }
};

Answer 2

You could maybe try this

After declaring const memberProfiles = [];

 let membersPromises = [];
members.forEach((m) => { 

membersPromises.push(firebaseContext.db .collection("users") .doc(m.uid) .get());

Promise.all(membersPromises).then(profiles=>{

profiles.forEach(profile=>{

memberProfiles.push(profile.data());

});


resolve(memberProfiles);
}).catch((err) => reject(err)); });