Welcome! Please use this template for reporting bugs or requesting features. For questions about using Workbox, the best place to ask is Stack Overflow, tagged with [workbox]: https://stackoverflow.com/questions/ask?tags=workbox

Library Affected:
workbox-webpack-plugin

Browser & Platform:
any browser, Windows OS build systems

Issue or Feature Request Description:
The path injected to the precache manifest uses windows file separators (), and the manifestTransforms option I would like to use to fix it thows this warning:

WARNING in You're using the following Workbox configuration options: [manifestTransforms]. This will not have any effect, as it will only modify files that are matched via 'globPatterns'. You can remove them from your config, and learn more at https://goo.gl/EQ4Rhm