Just run npm test and you will see PureScript code run inside Karma.

A simple karma configuration:

module.exports = config => { config.set({ autoWatch: true, browsers: ["Chrome"], files: [ "karma/index.js", ], reporters: ["spec"], singleRun: false }) }

Then just compile your tests to karma/index.js with

pulp browserify --main 'Test.Main' -I test --to karma/index.js

and run the tests with

karma start --single-run

Check the packcage.json to see how to automate that with npm scripts.