Should I return X in async functions, or should I return "Promise.Resolve(X)"?

Question

Should I return X in async functions, or should I return "Promise.Resolve(X)"?

I've always found this to be a tricky concept to fully grasp.

Let's delve into async functions in Typescript. Which implementation is accurate?

async function asyncFunctionOne(string1: string, string2: string, string3: string) {
    var returnObject1 = new object {
        fieldOne: object1,
        fieldTwo: object2,
        fieldThree: object3
    }

    return Promise.resolve(returnObject1)
}

async function asyncFunctionTwo(string1: string, string2: string, string3: string) {
    var returnObject2 = new object {
        fieldOne: object1,
        fieldTwo: object2,
        fieldThree: object3
    }

    return returnObject2;
}

Furthermore, let's imagine we're utilizing these functions and require the response for further processing within our application. Should we await the first function, the second function, both, or neither?

javascript typescript asynchronous

Answer 1

Answer №1

It's important to note that async functions always return a promise. Even if a plain return value is used, it will be wrapped with a resolved promise every time. The following code demonstrates how the same result can be achieved using either await or Promise.then.

(async function() {

   async function asyncFunctionTwo() {
      return 999;
   }


   asyncFunctionTwo().then((val => console.log(val)));
   
   //OR
   
   console.log(await asyncFunctionTwo())

})();

Answer 2

It's important to note that async functions always return a promise. Even if a plain return value is used, it will be wrapped with a resolved promise every time. The following code demonstrates how the same result can be achieved using either await or Promise.then.

(async function() {

   async function asyncFunctionTwo() {
      return 999;
   }


   asyncFunctionTwo().then((val => console.log(val)));
   
   //OR
   
   console.log(await asyncFunctionTwo())

})();

Should I return X in async functions, or should I return "Promise.Resolve(X)"?

Answer №1

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