Implementation:Nightwatchjs Nightwatch Extension Invocation Pattern

Knowledge Sources	Nightwatch Nightwatch Custom Commands
Domains	Testing, Extensibility
Last Updated	2026-02-12 00:00 GMT

Overview

Pattern for invoking custom commands and assertions in Nightwatch.js tests, demonstrating seamless integration with the built-in API.

Description

Custom commands are called via browser.commandName(args) for root-level commands, browser.namespace.commandName(args) for namespaced commands, and browser.assert.assertionName(args) for assertions. No import or setup is needed in test files; extensions are globally available once paths are configured.

Usage

Call custom commands and assertions in tests exactly like built-in commands. Ensure custom_commands_path and custom_assertions_path are configured in nightwatch.conf.js.

Code Reference

Source Location

• Repository: nightwatch
• File: test/apidemos/custom-commands/testNamespacedAliases.js (lines 1-17)
• File: test/apidemos/custom-commands/testUsingAutoInvokeCommand.js (lines 1-12)

Signature

// Custom command invocation
browser.strictClick(selector: string) -> browser

// Namespaced command invocation
browser.angular.getElementsInList(listName: string) -> Promise

// Custom assertion invocation
browser.assert.testCustomAssertion(selector, attribute, expected, msg?) -> browser
browser.verify.testCustomAssertion(selector, attribute, expected, msg?) -> browser

Import

// No import required - extensions are globally available

I/O Contract

Inputs

Name	Type	Required	Description
Command arguments	any	Varies	As defined by the custom command's command() method
Assertion arguments	any	Varies	As defined by the custom assertion's exports.assertion function

Outputs

Name	Type	Description
browser (chaining)	NightwatchAPI	Commands return browser for chaining
Assertion result	Pass/Fail	Logged to console and reporter

Usage Examples

Using Custom Commands and Assertions

describe('Test with custom extensions', function() {
  it('uses custom strictClick command', function(browser) {
    browser
      .navigateTo('https://example.com')
      .strictClick('#login-button')  // Custom command
      .setValue('#username', 'admin')
      .strictClick('#submit');       // Reuse custom command
  });

  it('uses custom assertion', function(browser) {
    browser
      .navigateTo('https://example.com')
      .assert.testCustomAssertion('#elem', 'data-role', 'admin')
      .verify.testCustomAssertion('#other', 'data-type', 'button');
  });

  it('uses namespaced command', function(browser) {
    browser
      .navigateTo('https://example.com/angular-app')
      .angular.getElementsInList('item in todoItems');
  });
});

Related Pages

Implements Principle

• Principle:Nightwatchjs_Nightwatch_Extension_Usage_In_Tests