when:
        watchingVirtualFileSystem.updateRootUnderLock { root -> nonEmptySnapshotHierarchy }
        watchingVirtualFileSystem.afterBuildStarted(WatchMode.DISABLED, VfsLogging.NORMAL, WatchLogging.NORMAL, buildOperationRunner)
        then:
        0 * _

        watchingVirtualFileSystem.root == emptySnapshotHierarchy

        when:

    def buildOperationRunner = new TestBuildOperationRunner()

    def "invalidates the virtual file system before and after the build (watch mode: #watchMode.description)"() {
        when:
        watchingNotSupportedVfs.afterBuildStarted(watchMode, VfsLogging.NORMAL, WatchLogging.NORMAL, buildOperationRunner)
        then:
        watchingNotSupportedVfs.root == emptySnapshotHierarchy

        when:

     * is supported on the current operating system, it is enabled for the build, and has been successfully
     * started.
     */
    boolean afterBuildStarted(WatchMode watchingEnabled, VfsLogging vfsLogging, WatchLogging watchLogging, BuildOperationRunner buildOperationRunner);

    /**
     * Register a watchable hierarchy.
     *

    protected SnapshotHierarchy updateNotifyingListeners(UpdateFunction updateFunction) {
        return updateFunction.update(SnapshotHierarchy.NodeDiffListener.NOOP);
    }

    @Override
    public boolean afterBuildStarted(
        WatchMode watchMode,
        VfsLogging vfsLogging,
        WatchLogging watchLogging,
        BuildOperationRunner buildOperationRunner
    ) {
        if (watchMode == WatchMode.ENABLED) {

                watchRegistry.virtualFileSystemContentsChanged(removedSnapshots, addedSnapshots, newRoot)
            ));
        }
    }

    @Override
    public boolean afterBuildStarted(
        WatchMode watchMode,
        VfsLogging vfsLogging,
        WatchLogging watchLogging,
        BuildOperationRunner buildOperationRunner
    ) {