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

        watchingVirtualFileSystem.root == emptySnapshotHierarchy

        when:

        _ * startParameter.isVfsVerboseLogging() >> (vfsLogging == VfsLogging.VERBOSE)

        when:
        runner.run(buildAction, buildController)

        then:
        1 * watchingHandler.afterBuildStarted(watchMode, vfsLogging, watchLogging, buildOperationRunner) >> actuallyEnabled

        then:

    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) {

                    break;
            }
        }

        LOGGER.debug("Watching the file system computed to be {}", watchFileSystemMode.getDescription());
        boolean actuallyWatching = virtualFileSystem.afterBuildStarted(
            watchFileSystemMode,
            verboseVfsLogging,
            debugWatchLogging,
            buildOperationRunner
        );

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

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