NoSuchSessionError with custom Firefox driver

[kjaouadi]

When creating my customDriver.js based on the Firefox driver defined in the selenium-cucumber-js repository mainly to set custom browser Options (headless, private, etc.) the app is throwing the following NoSuchSessionError:

NoSuchSessionError: Tried to run command without establishing a connection
         at Object.throwDecodedError (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/error.js:514:15)
         at parseHttpResponse (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/http.js:519:13)
         at /home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/http.js:441:30
         at processTicksAndRejections (internal/process/task_queues.js:93:5)
     From: Task: WebDriver.quit()
         at thenableWebDriverProxy.schedule (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/webdriver.js:807:17)
         at thenableWebDriverProxy.quit (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/webdriver.js:840:23)
         at /home/ubuntu/tools/jenkins.plugins.nodejs.tools.NodeJSInstallation/node13/lib/node_modules/selenium-cucumber-js/runtime/world.js:175:27
         at ManagedPromise.invokeCallback_ (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/promise.js:1376:14)
         at TaskQueue.execute_ (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/promise.js:3084:14)
         at TaskQueue.executeNext_ (/home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/promise.js:3067:27)
         at /home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/promise.js:2927:27
         at /home/ubuntu/workspace/b2b-portal_dev/node_modules/selenium-webdriver/lib/promise.js:668:7
         at processTicksAndRejections (internal/process/task_queues.js:93:5)

After troubleshooting, the error seems related to the closeBrowser() function where basically Firefox cannot be closed "twice". However, since browserName variable seems not being set for custom driver.

selenium-cucumber-js/runtime/world.js

Lines 171 to 178 in 23d40df

	function closeBrowser() {
	// firefox quits on driver.close on the last window
	return driver.close().then(function () {
	if (browserName !== 'firefox'){
	return driver.quit();
	}
	});
	}

@john-doherty would you consider instead of relying on the browserName variable set in getDriverInstance() function to query the browserName from the current driver session via the following snippet?

function closeBrowser() {
    driver.getCapabilities().then(function (caps) {
          browserName = caps.get("browserName");
      });
    // firefox quits on driver.close on the last window
    return driver.close().then(function () {
        if (browserName !== 'firefox'){
            return driver.quit();
        }
    });
}