Comparing File objects in JavaScript

Question

I have a drop zone for files in a JS application. I want to filter out duplicate files being dropped into the application, but I can't seem to find a proper way to compare two File objects pointing to the same file. All I could find is comparison by "name + file size + modified date" combo, but it's not 100% proof, since the path is not revealed in the name attribute.

Is there a way to do it that I just missed?

Answer 1

I know that the answer comes too late, but I was confronting with the same issue and maybe others too.

I doubt that there is a better method than the one that you're using. Indeed it's not 100% proof because you can have two files with the same name, size and last modified date, but they can sit in two separate folders and be different.

Using equality (===) between File objects is also failing if you have the same file chosen by two different <input type="file">.

I think another way will be in addition to what you've done to use FileReader to actually compare the files by content. But this will be very expensive.