For those developing Electron apps, how do you handle cross-platform testing?

I'm currently developing an Electron app, which is only available for macOS at the moment because that's the platform I use and can test production builds on.

After launching this week on Product Hunt, I received feedback from a user who wished it was available for Windows. I'd like to expand support to Windows, but not really sure about the best approach to test and verify that it all works.

For those of you working on Electron apps, how do you handle cross-platform testing to ensure everything works smoothly?