No prompt to accept files when Airdropped to myself? Ive just airdropped a file from my phone (iPhone 8, iOS 12.x) to my computer (MacBook Pro, OSX 10.13.x). Both devices use the same Apple / iCloud ID. 

The file was received fine, but I was not required to confirm acceptance of the file on my computer. My concern is that someone could send me a file maliciously. 

My computers AirDrop settings are set to "Allow me to be discovered by Contacts Only."

If another contact with a different Apple ID tried to Airdrop a file to my computer, would my computer ask me to accept it ?
According to Apple:


  If you AirDrop content to yourself, like share a photo from your iPhone to your Mac, you won't see an option to Accept or Decline. The content is automatically sent to that device. Just make sure that both devices are signed in with the same Apple ID.


AirDrop is working as designed.  I don't think you need to worry about someone sending you malicious content.