Karma/Electron 9 hanging issue

This repo reproduces an issue that occurs with Karma and Electron 9 when running Jasmine tests using client.useIframe = false. To see the issue, first install dependencies using npm run install, then run npm run test-no-iframe. The single test should run successfully, but hang after completion.

This issue doesn't happen when IFrames are enabled. Run npm run test-iframe and you should see the tests run successfully and Karma exit properly with status 0.

Note

This appears to be an issue with Electron 9 only. Electron 8 works as expected.

Why does this matter?

IFrame's don't work with Electron's nodeIntegration: true option, so new browser windows must be used instead.