Javascript Unit Testing Environment (JUTE) JUTE is a standalone HTTP server that serves your test files to a JUTE backend for testing. Three of the four backends (Selenium, Capture, and PhantomJS) serve files to a browser, the third backend (V8) will run your tests directly in V8. JUTE then collects and stores test output in JUnit XML format and code coverage information in 'lcov' format and generates pretty HTML to view your coverage results.