The **grunt-not-constantinople** plugin adds a Grunt task that wraps Istanbul, letting developers generate code‑coverage reports for any JavaScript unit‑testing framework (e.g., Mocha, Nodeunit). By configuring the task with the name of the test runner, source paths, thresholds and report formats, it automatically runs the tests, instruments the code, cleans old coverage data, and fails the build if coverage falls below the specified percentages—making it useful for JavaScript developers who use Grunt to enforce test coverage standards.