如何使用承诺等待函数执行以等待其在 Javascript/Node JS 中的回调

Question

I have two functions say async foo() and bar()

Lets say exe time of foo() => 5 seconds

exe time of bar() => 10 seconds

Code looks something like

await foo();

async foo(){
//body 
bar()
}

PROBLEM:

Here foo() takes 5 seconds to execute (the body part) so it returns a successful promise without waiting for the execution of bar() to complete

QUESTION:

How do i make sure that foo() only returns a promise when bar() completes its execution maybe using promise to wait on the callback of bar() but i'm not sure how to exactly go about it

Note: Can't declare bar as async since it is imported from some other module

Answer 1

You can promisify methods of aws-sdk 's services just by appending the method with .promise ;

await foo();

foo(){
  return ses.sendTemplatedEmail(params).promise();
}

OR

    await foo();

    async foo(){
      try {
        let res = await ses.sendTemplatedEmail(params).promise();
        console.log(res)
     }catch(err) {
        console.log(err)
       }
    }

Answer 2

You can try below code

await foo();

    foo() {
        return new Promise(async resolve => {
           const result =await bar()
              if (result) {
                resolve(true)   
              }

        })
      }