growing file behavior

We are looking to script WinSCP to get files from our SFTP server on a recurring schedule (every 2 minutes). If another user at a different location is simultaneously uploading a file and that file is growing, how does WinSCP handle that? Will it wait for the file to finish growing? Or will it proceed with downloading the incomplete file? (and then fail the deletion of the incomplete source file?)

Thank you in advance for any info.

It's rather a question for your SFTP server provider. But in general the answer would be that it will download the incomplete file.

You can make the user uploading the file upload it to a temporary name, either explicitly or automatically:
https://winscp.net/eng/docs/resume#automatic
https://winscp.net/eng/docs/ui_pref_resume
and make sure you won't be downloading the temporary files (using exclusion mask).

We aren't able to control the application that users will be uploading files with. Thanks for the suggestions though!