Running tests:

yarn test

Testing a specific browser:

yarn test --browsers FirefoxNightly

In test watch mode:

npx karma start --browsers FirefoxNightly

The version of karma-firefox-launcher used here should work under WSL but for Chrome you'll want to use something like:

CHROME_BIN=/mnt/c/Program\ Files\ \(x86\)/Google/Chrome/Application/chrome.exe npx karma start --browsers Chrome

That will complain about not being able to write to the temp directory but otherwise should be fine.