Return statement of a function doesn't get triggered after using it in Express FileUpload .mv() method

I'm trying to upload a file through Express File Upload but getting an undefined value of the function in which it is being called.

I have this function which checks if the user chose a single file or multiple files. To keep it simple I am just going to show the issue in single file upload. That is req.files.fileInput is an object instead of an array of objects.

Here's the code:

const fileCheck = ( file ) => {         if ( Array.isArray( file ) ) {            // ignore this part of the if block as I'm testing it out with single file upload            console.log( 'THE USER WANTS TO UPLOAD MULTIPLE FILES' );         } else if ( typeof file === 'object' ) {            console.log( 'THE USER WANTS TO UPLOAD A SINGLE FILE' );            const uploadPath = `./resources/images/${file.name}`;            file.mv( uploadPath, function ( err ) {              if ( err ) {                  console.error( err );                    return {                      success: false,                      message: 'Something went wrong. Please upload again!',                      data: null                  };              }                return {                  success: true,                  message: 'File Uploaded Successfully!',                  data: file.name              };             });         }    };      const { success, message, data } = fileCheck(req.files.fileInput);    // IT IS UNDEFINED BUT IT IS SUPPOSED TO BE TRUE IF FILE UPLOAD IS SUCCESSFUL.  // IT IS ALSO UNDEFINED INSTEAD OF FALSE IF THERE IS AN ERROR IN FILE UPLOAD.   console.log( success );   

I get this error:

TypeError: Cannot destructure property 'success' of '(intermediate value)' as it is undefined.  

Seems like fileCheck function's return statement isn't getting triggered after using it in .mv() method. What could be the reason here? And what can I do to solve it?

https://stackoverflow.com/questions/67389805/return-statement-of-a-function-doesnt-get-triggered-after-using-it-in-express-f May 05, 2021 at 01:54AM