Implementation:Nightwatchjs Nightwatch Session Cleanup API

Knowledge Sources	Nightwatch Nightwatch Programmatic API
Domains	Testing, API, Resource_Management
Last Updated	2026-02-12 00:00 GMT

Overview

Concrete API for terminating browser sessions and cleaning up Nightwatch client resources via browser.end(), browser.quit(), and client.cleanup().

Description

browser.end() ends the Nightwatch session and closes the browser. browser.quit() is an alias that terminates the WebDriver session. client.cleanup() waits for the command queue to complete, empties and resets the queue, removes all listeners, and resets the logger. For complete cleanup, call browser.end() followed by client.cleanup().

Usage

Call browser.end() to close the browser, then client.cleanup() to release internal resources. Essential in programmatic usage.

Code Reference

Source Location

• Repository: nightwatch
• File: lib/index.js (lines 174-180)
• File: api/index.js (line 13)

Signature

// Browser session termination
browser.end() -> Promise<void>    // End session and close browser
browser.quit() -> Promise<void>   // Alias: terminate WebDriver session

// Client resource cleanup
client.cleanup() -> Promise<void>
// Internally:
//   await client.queue.waitForCompletion()
//   client.queue.empty()
//   client.queue.reset()
//   client.queue.removeAllListeners()
//   Logger.reset()

Import

// Methods available on browser and client objects
// No separate import needed

I/O Contract

Inputs

Name	Type	Required	Description
Active browser session	NightwatchAPI	Yes	Browser instance from launchBrowser()
Active client	ClientWrapper	Yes	Client from createClient()

Outputs

Name	Type	Description
Session closed	void	WebDriver session terminated, browser process ended
Queue cleared	void	Command queue emptied, listeners removed
Logger reset	void	Internal logger state cleared

Usage Examples

Complete Cleanup

const Nightwatch = require('nightwatch');

(async function() {
  const client = Nightwatch.createClient({
    browserName: 'chrome',
    headless: true
  });

  const browser = await client.launchBrowser();

  try {
    await browser.navigateTo('https://example.com');
    await browser.assert.titleContains('Example');
  } finally {
    // Always cleanup, even on error
    await browser.end();
    await client.cleanup();
  }
})();

Cleanup in Test Hooks

describe('Programmatic test', function() {
  let client, browser;

  before(async function() {
    client = Nightwatch.createClient({ browserName: 'chrome' });
    browser = await client.launchBrowser();
  });

  after(async function() {
    await browser.end();
    await client.cleanup();
  });

  it('runs a test', async function() {
    await browser.navigateTo('https://example.com');
  });
});

Related Pages

Implements Principle

• Principle:Nightwatchjs_Nightwatch_Session_Cleanup

Requires Environment

• Environment:Nightwatchjs_Nightwatch_Selenium_WebDriver_4