Is there a way to detect if any test has failed from within test code?

describe('some tests', function () {
  /*
   * Run some tests...
   */
})

after(function () {
  failures = ? // <--- what goes here?
  console.log(failures + " tests failed!")
})

I'd use this to keep chromedriver's browser open if a test failed, and to report success or failure to sauce labs after tests run. I could see pulling saucelabs reporting out into a reporter using multiple reporters #930, but keeping chromedriver open makes most sense in test code, where we launch the browser.

Runner and Reporters have the info I'm looking for as stats but I'm not sure how to get to them from within a test file.