For Polymer, you usually use web-component-tester (WCT) to test your components, and the web-component-tester-istanbul plugin to cover the code. You configured wct.conf.json in the root of your project like this:
{ "suites": [ "test/components/my-view1/my-view1.html" ], "plugins": { "istanbul": { "dir": "./build/coverage", "reporters": [ "text-summary", "lcov" ], "include": [ "*.js", "*.html" ], "exclude": [] } } }
And then run wct , which will output something like this:
Unfortunately, a recent WCT update made the coverage plugin incompatible , so the plugin is never called, so coverage is always displayed as 100% (0/0) (no lines are visible, no lines are visible).