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Testing Promise Detection Implementation in video.js

This test suite validates Promise utility functions in Video.js, focusing on Promise detection and verification capabilities. The tests ensure proper identification of both native Promises and Promise-like objects with thenable interfaces.

Test Coverage Overview

The test suite provides comprehensive coverage of Promise utility functions in Video.js.

Key areas tested include:

Native Promise detection and validation
Promise-like object identification
Thenable interface verification

The tests specifically cover edge cases around object structure and Promise compatibility.

Implementation Analysis

The testing approach utilizes QUnit’s module and test structure to isolate Promise utility validations. The implementation leverages QUnit’s assertion patterns to verify Promise detection logic, with specific focus on the isPromise utility function. Tests are structured to validate both positive and negative cases using window.Promise and custom objects.

Technical Details

Testing infrastructure includes:

QUnit as the primary testing framework
ESLint configuration for QUnit environment
Global window object import for native Promise access
Custom promise utility module imports

Best Practices Demonstrated

The test suite exemplifies strong testing practices through clear separation of concerns and thorough validation scenarios. Notable practices include:

Isolated test cases for specific functionality
Explicit assertion messages
Comprehensive positive and negative test cases
Clean and maintainable test structure

videojs/videoJs

test/unit/utils/promise.test.js

            
/* eslint-env qunit */
import window from 'global/window';
import * as promise from '../../../src/js/utils/promise';

QUnit.module('utils/promise');

QUnit.test('can correctly identify a native Promise (if supported)', function(assert) {
  assert.ok(promise.isPromise(new window.Promise((resolve) => resolve())), 'a native Promise was recognized');
});

QUnit.test('can identify a Promise-like object', function(assert) {
  assert.notOk(promise.isPromise({}), 'an object without a `then` method is not Promise-like');
  assert.ok(promise.isPromise({then: () => {}}), 'an object with a `then` method is Promise-like');
});