iOS proving file is accessible for upload from share extension to reactnative

Is there a test way to prove I have access to a file? I'm using

if ([[NSFileManager defaultManager] fileExistsAtPath:[url path]]){

                long long fileSize = [[[NSFileManager defaultManager] attributesOfItemAtPath:url.absoluteString error:nil][NSFileSize] longLongValue];
                NSLog(@"sik: %lld", fileSize); }

I have the if returning positive and I can see the fileSize, but I want to be sure I have access to the file, I was thinking on sending the file to firebase to prove I have access to it, what another way can I prove I have access to the file?

This is inside a share extension, that wants to attach some MS word file, I can see the file exists, and the size, but have some problems accessing the path from react native... so for the moment I just want to prove iOS have access to it... Thanks!

Because of iOS apps being sandboxed by default, if you can see the file, you have access to it.

What you could do is load the file into a variable and then inspect its contents, if you’re really uncertain.