Test Runner & Configuration

/**
 * Configures and starts the QUnit test runner with Ember-specific setup
 * @param options - Configuration options for test runner behavior
 */
function start(options?: QUnitStartOptions): void;

interface QUnitStartOptions {
  /** If false, test container will not be setup based on URL params, defaults to true */
  setupTestContainer?: boolean;
  /** If false, tests will not be automatically started, defaults to true */
  startTests?: boolean;
  /** If false, default Ember.Test adapter will not be updated, defaults to true */
  setupTestAdapter?: boolean;
  /** If false, opts out of setting Ember.testing during tests, defaults to true */
  setupEmberTesting?: boolean;
  /** If false, test isolation validation will be disabled */
  setupTestIsolationValidation?: boolean;
  /** Max time in milliseconds allowed after test completion for async to settle, defaults to 50 */
  testIsolationValidationDelay?: number;
}

// tests/test-helper.js - Standard setup
import Application from '../app';
import config from '../config/environment';
import { setApplication } from '@ember/test-helpers';
import { start } from 'ember-qunit';

setApplication(Application.create(config.APP));

start();

// Custom configuration
start({
  setupTestContainer: true,
  startTests: true,
  setupTestAdapter: true,
  setupEmberTesting: true,
  setupTestIsolationValidation: true,
  testIsolationValidationDelay: 100
});

/**
 * Configures test container display based on URL parameters:
 * - ?nocontainer - hides the test container
 * - ?devmode or ?fullscreencontainer - makes container full screen
 */
function setupTestContainer(): void;

/**
 * Configures the custom QUnit adapter for Ember's async testing needs
 */
function setupTestAdapter(): void;

/**
 * Sets Ember.testing to true before each test and false after each test
 * This is critical for proper Ember test behavior
 */
function setupEmberTesting(): void;

/**
 * Creates a validation test to ensure Ember.onerror handler 
 * properly re-throws exceptions when Ember.testing is true
 */
function setupEmberOnerrorValidation(): void;

/**
 * Resets Ember.onerror after each test completion
 * Called automatically by start() to prevent error handlers from affecting other tests
 */
function setupResetOnerror(): void;

/**
 * Enables detection of tests that aren't properly isolated
 * (have pending timers, runloops, AJAX requests, or waiters)
 * @param delay - Maximum time in milliseconds to wait for settlement, defaults to 50
 */
function setupTestIsolationValidation(delay?: number): void;

/**
 * Calls QUnit.start() to begin test execution
 */
function startTests(): void;

/**
 * Custom QUnit adapter for Ember.js applications
 * Handles async test coordination between Ember and QUnit
 */
class QUnitAdapter extends EmberTestAdapter {
  /** Initialize adapter with QUnit reference and done callback tracking */
  init(): void;
  
  /** Handle start of async operation in tests */
  asyncStart(): void;
  
  /** Handle end of async operation in tests */
  asyncEnd(): void;
}

/**
 * Empty callback function used when no test is currently running
 */
function nonTestDoneCallback(): void;

// Manual adapter setup (normally done by start())
import { QUnitAdapter, setupTestAdapter } from 'ember-qunit';
import { setAdapter } from 'ember-testing/lib/test/adapter';

// Option 1: Use convenience function
setupTestAdapter();

// Option 2: Manual setup
setAdapter(QUnitAdapter.create());