- Testing your Electron apps with ChromeDriver
- Write Automated Tests for Electron With Spectron, Mocha, and Chai (alternate link)
- Instrumenting Electron Apps for Security Testing
- Spectron questions on Stack Overflow
You can also test Electron applications with Selenium (the Applitools service that blog post is pimping looks pretty cool as well and they have a free trial and an open-source project licensing program). Here's more on Selenium and WebDriver from the Electron site.