Demonstrate Node.js 25650 Bug

In Node.js 11.7.0, a bug was introduced that results in the following command:

npm t

Outputting an empty coverage report. In older versions of Node.js, a correct 100% coverage report is output.

The underlying cause appears to be that the registered exit handler in nyc no longer fires:

onExit(function () {
  _this.writeCoverageFile()
}, {alwaysLast: true})

☝ mocha has its own exit handler, one hunch is perhaps two exit handlers being run in conjunction no longer works.