def "watchers are stopped when removing the last watched snapshot"() {
        def rootDir = file("root").createDir()
        ["first", "second", "third"].collect { rootDir.createFile(it) }
        def rootDirSnapshot = snapshotDirectory(rootDir)

        when:
        registerWatchableHierarchies([rootDir])
        addSnapshot(rootDirSnapshot)
        then:
        1 * watcher.startWatching({ equalIgnoringOrder(it, [rootDir]) })