npm install svn-get-revision
svn-get-revision c:\location\of\your\working_copy > svn_latest_revision.txt
Now you have a txt file containing your latest revision. This can be ran at build time to get you the latest version information to be used in something like a package.json file to seed the version in your app. My use case was the fact that we still use SVN at work and I needed it to play nice with CI.