监视Mockito中的路径

Question

I'm trying to spy on a Path using Mockito

dirSpy = spy(Files.createTempDirectory(DIR_NAME));

and I get an error saying

Mockito cannot mock this class: class sun.nio.fs.UnixPath
Mockito can only mock visible & non-final classes.
If you're not sure why you're getting this error, please report to the mailing list.

[I can post a longer stack trace if you think it is needed]

I assume that this is because the Path has a native implementation - my question is if there is some workaround that will enable me to check if a specific location was accessed during a test

what I'm trying to test- I have a directories structure for each user - I wanted to do a test that checks that in the case that there are no users, there isn't a redundant work done and that the root of all users isn't accessed.

In my over whole test logic this is a minor verification and i can do without it - just thought it's something that is nice to have

Answer 1

my question is if there is some workaround that will enable me to check if a specific location was accessed during a test

Yes, using a WatchService .

Note that should you be able to do it, watching the path itself won't bring you much: operations on Path s don't do I/O except for .toRealPath() if called at all and if the filesystem has symlinks support (OK, you use some Unix variant, so that is likely to be the case). The real I/O is done by the path's FileSystemProvider . But you won't be able to spy that either...

A WatchService is therefore your best solution.

See here for an example. And please note that a WatchService is filesystem dependent; this means you are still better off doing file I/O from a class of yours which you can spy ;)