WIP: Convert to TypeScript

.ember-cli

@@ -11,5 +11,5 @@
   Setting `isTypeScriptProject` to true will force the blueprint generators to generate TypeScript
   rather than JavaScript by default, when a TypeScript version of a given blueprint is available.
   */
-  "isTypeScriptProject": false
+  "isTypeScriptProject": true
 }

.eslintignore

@@ -15,6 +15,8 @@
 !.*
 .*/
 .eslintcache
+/.yalc*
+/yalc.lock
 
 # ember-try
 /.node_modules.ember-try/

.eslintrc.js

@@ -1,5 +1,28 @@
 'use strict';
 
+const sharedTSOptions = {
+  extends: [
+    'eslint:recommended',
+    'plugin:@typescript-eslint/recommended',
+    'plugin:@typescript-eslint/recommended-requiring-type-checking',
+    'plugin:@typescript-eslint/strict',
+  ],
+  parser: '@typescript-eslint/parser',
+  plugins: ['@typescript-eslint'],
+  rules: {
+    '@typescript-eslint/array-type': ['error', { default: 'array-simple' }],
+    '@typescript-eslint/consistent-type-exports': 'error',
+    '@typescript-eslint/consistent-type-imports': 'error',
+    '@typescript-eslint/explicit-function-return-type': 'error',
+    '@typescript-eslint/method-signature-style': 'error',
+    '@typescript-eslint/no-confusing-void-expression': 'error',
+    '@typescript-eslint/no-redundant-type-constituents': 'error',
+    '@typescript-eslint/prefer-enum-initializers': 'error',
+    '@typescript-eslint/prefer-readonly': 'error',
+    '@typescript-eslint/promise-function-async': 'error',
+  },
+};
+
 module.exports = {
   root: true,
   extends: ['eslint:recommended', 'plugin:prettier/recommended'],
@@ -45,6 +68,30 @@ module.exports = {
       extends: ['plugin:node/recommended'],
     },
 
+    // ts files
+    {
+      files: ['**/*.ts'],
+      parserOptions: {
+        tsconfigRootDir: __dirname,
+        project: ['./tsconfig.json'],
+      },
+      ...sharedTSOptions,
+    },
+
+    // ts-tests files
+    {
+      files: ['type-tests/**/*.ts'],
+      parserOptions: {
+        tsconfigRootDir: __dirname,
+        project: ['./type-tests/tsconfig.json'],
+      },
+      ...sharedTSOptions,
+      rules: {
+        '@typescript-eslint/no-empty-function': 'off',
+        '@typescript-eslint/no-unused-vars': 'off',
+      },
+    },
+
     // test files
     {
       files: ['tests/**/*.js'],

.gitignore

@@ -20,6 +20,9 @@
 /npm-debug.log*
 /testem.log
 /yarn-error.log
+/.yalc*
+/yalc.lock
+/.vscode*
 
 # ember-try
 /.node_modules.ember-try/

.prettierignore

@@ -15,6 +15,8 @@
 !.*
 .eslintcache
 .lint-todo/
+/.yalc*
+/yalc.lock
 
 # ember-try
 /.node_modules.ember-try/

addon-test-support/adapter.ts

@@ -0,0 +1,106 @@
+import { assert } from '@ember/debug';
+import type EmberTestAdapter from '@ember/test/adapter';
+import hasEmberVersion from '@ember/test-helpers/has-ember-version';
+import Ember from 'ember';
+
+import * as QUnit from 'qunit';
+
+import { isRecord, isTest } from './types/util';
+
+function unhandledRejectionAssertion(current: unknown, error: unknown): void {
+  let message: string;
+  let source: string | undefined;
+
+  if (
+    isRecord(error) &&
+    'message' in error &&
+    typeof error['message'] === 'string'
+  ) {
+    message = error['message'];
+    source = typeof error['stack'] === 'string' ? error['stack'] : undefined;
+  } else if (typeof error === 'string') {
+    message = error;
+    source = 'unknown source';
+  } else {
+    message = 'unhandledRejection occurred, but it had no message';
+    source = 'unknown source';
+  }
+
+  assert(
+    'expected current test to have an assert',
+    isTest(current) && 'assert' in current
+  );
+  current.assert.pushResult({
+    result: false,
+    actual: false,
+    expected: true,
+    message: message,
+    source,
+  });
+}
+
+export function nonTestDoneCallback(): void {
+  // no-op
+}
+
+interface QUnitAdapter extends EmberTestAdapter {
+  doneCallbacks: Array<{ test: unknown; done: () => void }>;
+  qunit: QUnit;
+}
+
+// @ts-expect-error `extend` does not exist on Adapter
+// eslint-disable-next-line @typescript-eslint/no-unsafe-call
+let Adapter = Ember.Test.Adapter.extend({
+  init(this: QUnitAdapter) {
+    this.doneCallbacks = [];
+    this.qunit ??= QUnit;
+  },
+
+  asyncStart(this: QUnitAdapter) {
+    const currentTest: unknown = this.qunit.config.current;
+    const done =
+      isTest(currentTest) && 'assert' in currentTest
+        ? currentTest.assert.async()
+        : nonTestDoneCallback;
+    this.doneCallbacks.push({ test: currentTest, done });
+  },
+
+  asyncEnd(this: QUnitAdapter) {
+    const currentCallback = this.doneCallbacks.pop();
+
+    if (!currentCallback) {
+      throw new Error(
+        'Adapter asyncEnd called when no async was expected. Please create an issue in ember-qunit.'
+      );
+    }
+
+    const { test, done } = currentCallback;
+
+    // In future, we should explore fixing this at a different level, specifically
+    // addressing the pairing of asyncStart/asyncEnd behavior in a more consistent way.
+    if (test === this.qunit.config.current) {
+      done();
+    }
+  },
+
+  // clobber default implementation of `exception` will be added back for Ember
+  // < 2.17 just below...
+  exception: null,
+}) as QUnitAdapter;
+
+// Ember 2.17 and higher do not require the test adapter to have an `exception`
+// method When `exception` is not present, the unhandled rejection is
+// automatically re-thrown and will therefore hit QUnit's own global error
+// handler (therefore appropriately causing test failure)
+if (!hasEmberVersion(2, 17)) {
+  // @ts-expect-error `extend` does not exist on Adapter
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-call
+  Adapter = Adapter.extend({
+    exception(error: unknown) {
+      const currentTest: unknown = QUnit.config.current;
+      unhandledRejectionAssertion(currentTest, error);
+    },
+  }) as QUnitAdapter;
+}
+
+export default Adapter;