How to return Boolean instead Promise

Question

I have that problem almost a week. I read a lot articles about Promise and how to return value, I even ask from the ChatGPT. But all solutions doesn't work.

Look example: I have condition with 4 functions. Every function execute an one check: (

One check quantity of files,
Second summary size of files,
Third Type of file and
Fourth - dimension on side Image

) it look like that:

if(
      this.checkQuantityFiles(filesArr)&&
      this.checkTotalFilesSize(filesArr)&&
      this.checkType(filesArr)&&
      this.checkImageDimension(filesArr)
    )

I did all functions beside checkImageDimension, cause that function consist a load image for which need a Promise.

  checkImageDimension(files:File[]):boolean{
    function isValidImage(image: HTMLImageElement): boolean {
          return image.width < MAXLIMITWIDTH && image.height < MAXLIMITHEIGH;
        }

    function loadImage(file: File): Promise<HTMLImageElement> {
          return new Promise((resolve, reject) => {
            const image = new Image();
            image.onload = () => resolve(image);
            image.onerror = reject;
            image.src = URL.createObjectURL(file);
          });
        }

        async function checkArray(){
         const imagePromises = files.map(loadImage);
         const images = await Promise.all(imagePromises);
         const every:Promise<boolean>=new Promise((resolve)=>{
           resolve( images.every(isValidImage))
         })
         const result=await every.then((res)=>{
           return res
         })
         console.log(result);
         return result
    }

    const result= checkArray().then((result)=>{return result},()=>{
      throw Error("Check array function invalid")
    })


    return result//// I should return boolean here but i can't make boolean from Promise<boolean>
  }

I tried set "await", use "then". But compiler don't give me return boolean if I have async function and remove async function - i can't set await and unwrap Promise. If i make an const and link her with async func as at the end my code I also to get Promise. Why?? I should to get value. Promise is finish.

Since the value will only be available asynchronously *sometime later*, there is no way to return it immediately. `checkImageDimension` itself must be async/return a promise, which must be awaited by its caller. — deceze, Jul 29 '23 at 07:12
@deceze but then how do i test 4 functions together? if 3 will be boolean and only one -Promise? — RobertcodeR, Jul 29 '23 at 07:16
Await the promise and then do the check with its return value…!? — deceze, Jul 29 '23 at 07:17
@RobertcodeR FYI, there is a utility type [`Awaited`](https://www.typescriptlang.org/docs/handbook/utility-types.html#awaitedtype) that may be useful for you. — NNL993, Jul 29 '23 at 07:25

How to return Boolean instead Promise

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