It seems the main bit that's missing here is that it doesn't actually print and parse the list of events? It seems always 0:

        have:
        	0        /
        	0        /file
        want:
        	0        /file

Here's what I would do:

1. Fix that.
2. Just remove all tests, as the behaviours seem too different.
3. Start adding them back one-by-one, fixing up the Output, removing the cross-platform bits that are no longer needed.

You can also use a different approach if that works better for you, but the end result should be something that has tests for at least a bunch of common situations: "make a new directory", "remove watched directory", etc. etc.

Added some tests now. The tests that are here run and pass (locally).

Behaviour is different from fsnotify, and I've mostly just replaced the test asserts with what is happening. These aren't really correctness tests at this point, just regression.

I also haven't really had anything to compare against, as there are not too many other tests here. That is something to keep in mind.

I was watching what was happening for each test though, and the events emitted do make sense with regards to what the test does, and what I could find on how fsevents work on mac os.

Behaviour is different from fsnotify, and I've mostly just replaced the test asserts with what is happening. These aren't really correctness tests at this point, just regression. I also haven't really had anything to compare against, as there are not too many other tests here. That is something to keep in mind.

Yeah, that's fine. The important bit here is to ensure the behaviour doesn't radically change and that it doesn't panic.

Also, can you add a test like so (completely untested code for illustrative purposes):

func TestMany(t *testing.T) {
	tmp := t.TempDir()
	var wg sync.WaitGroup
	wg.Add(300)
	for i := 0; i<100; i++ {
		i := i
		go func() { defer wg.Done(); echoAppend(fmt.Sprintf(%s/file-%d", tmp, i)) }()
		go func() { defer wg.Done(); mkdir(fmt.Sprintf(%s/dir-%d", tmp, i)) }()
		go func() { defer wg.Done(); echoAppend(fmt.Sprintf(%s/dir-%d/file-%d", tmp, i)) }()
	}
	wg.Wait()

	wg.Add(200)
	for i := 0; i<100; i++ {
		i := i
		go func() { defer wg.Done(); remove(fmt.Sprintf(%s/file-%d", tmp, i)) }()
		go func() { defer wg.Done(); removeAll(fmt.Sprintf(%s/dir-%d", tmp, i)) }()
	}
	wg.Wait()

	// Check if you have 100 writes for new files, 100 removes, etc.
}

That is, create 100 files and directories simultaneously in a watched directory, then remove them, and ensure we've got the right events.

After that and the minor comments it should be good to go.

Alright, I think this is mostly it.

I also wrote a short description of the test scripts in the readme.

I think I went through all your PR comments, also cleaned up some comments in code to remove stuff that was made irrelevant by being different from initial fsnotify code.

Let me know if I've missed something.

Seems good; thanks!