Refactor the internal Ember loader to use the standard Ember CLI loader

This PR refactors the internal Ember loader so that it uses the standard
Ember CLI loader instead for modules. This means that modules will be
defined in the main namespace, and importable from there, instead of in
a hidden namespace that only Ember can use.

Notes:

- Code is still loaded and built via `treeForVendor` and included as a
  vendor file. This needs to be the case for the time being for
  bootstrapping.
- Loader code is still included for Node support. If `define` and
  `require` are not already defined, then a backup shim is used instead.
- Modules are now exposed from Ember, but `ember-cli-babel` still
  transpiles them to global references. This unblocks us from being able
  to make all modules work normally, however.
- `require` shim module is no longer defined, we reference `define` and
  `require` as globals instead (which is more accurate). In the future
  we should update this to use Embroider's conventions.
- `__loader` is still exposed on the Ember object, referencing the same
  values as before.

.eslintrc.js

@@ -50,7 +50,7 @@ module.exports = {
         '@typescript-eslint/ban-types': 'off',
         '@typescript-eslint/no-empty-function': 'off',
         '@typescript-eslint/no-this-alias': 'off',
-        '@typescript-eslint/no-var-requires': 'warn',
+        '@typescript-eslint/no-var-requires': 'off',
 
         // TODO: Enable and fix these rules
         // Typescript provides better types with these rules enabled
@@ -81,6 +81,8 @@ module.exports = {
         Set: true,
         Symbol: true,
         WeakMap: true,
+        require: true,
+        define: true,
       },
 
       rules: {

broccoli/packages.js

@@ -5,7 +5,6 @@ const path = require('path');
 const Rollup = require('broccoli-rollup');
 const Funnel = require('broccoli-funnel');
 const MergeTrees = require('broccoli-merge-trees');
-const Babel = require('broccoli-babel-transpiler');
 const typescript = require('broccoli-typescript-compiler').default;
 const BroccoliDebug = require('broccoli-debug');
 const findLib = require('./find-lib');
@@ -18,7 +17,6 @@ const StringReplace = require('broccoli-string-replace');
 const GlimmerTemplatePrecompiler = require('./glimmer-template-compiler');
 const VERSION_PLACEHOLDER = /VERSION_STRING_PLACEHOLDER/g;
 const canaryFeatures = require('./canary-features');
-const injectNodeGlobals = require('./transforms/inject-node-globals');
 
 const debugTree = BroccoliDebug.buildDebugCallback('ember-source');
 
@@ -44,7 +42,7 @@ module.exports.jquery = function _jquery() {
   });
 };
 
-module.exports.internalLoader = function _internalLoader() {
+module.exports.loader = function _loader() {
   return new Funnel('packages/loader/lib', {
     files: ['index.js'],
     getDestinationPath() {
@@ -234,6 +232,7 @@ function glimmerTrees(entries) {
   let trees = [];
   let queue = Array.isArray(entries) ? entries.slice() : [entries];
   let name;
+
   while ((name = queue.pop()) !== undefined) {
     if (seen.has(name)) {
       continue;
@@ -255,14 +254,8 @@ function glimmerTrees(entries) {
       queue.push(...dependencies);
     }
   }
-  return new Babel(new MergeTrees(trees), {
-    sourceMaps: true,
-    plugins: [
-      // ensures `@glimmer/compiler` requiring `crypto` works properly
-      // in both browser and node-land
-      injectNodeGlobals,
-    ],
-  });
+
+  return new MergeTrees(trees);
 }
 
 module.exports.glimmerCompilerES = () => {

ember-cli-build.js

@@ -15,7 +15,7 @@ Error.stackTraceLimit = Infinity;
 const {
   routerES,
   jquery,
-  internalLoader,
+  loader,
   qunit,
   handlebarsES,
   rsvpES,
@@ -246,7 +246,14 @@ function templateCompilerBundle(emberPackages, transpileTree) {
 }
 
 function testHarness() {
-  return new MergeTrees([emptyTestem(), testPolyfills(), testIndexHTML(), qunit(), jquery()]);
+  return new MergeTrees([
+    emptyTestem(),
+    testPolyfills(),
+    testIndexHTML(),
+    loader(),
+    qunit(),
+    jquery(),
+  ]);
 }
 
 function emptyTestem() {
@@ -262,5 +269,5 @@ function templateCompilerDependencies() {
 }
 
 function emberHeaderFiles() {
-  return new MergeTrees([emberLicense(), internalLoader()]);
+  return new MergeTrees([emberLicense(), loader()]);
 }

lib/index.js

@@ -237,18 +237,11 @@ module.exports = {
     return new MergeTrees([
       concatBundle(emberFiles, {
         outputFile: 'ember.js',
-        footer: "require('ember');",
+        footer: "require('@ember/-internals/bootstrap');",
       }),
 
       concatBundle(emberTestingFiles, {
         outputFile: 'ember-testing.js',
-        footer: `
-          var testing = require('ember-testing');
-          Ember.Test = testing.Test;
-          Ember.Test.Adapter = testing.Adapter;
-          Ember.Test.QUnitAdapter = testing.QUnitAdapter;
-          Ember.setupForTesting = testing.setupForTesting;
-        `,
       }),
     ]);
   },

packages/@ember/-internals/bootstrap/index.js

@@ -0,0 +1,30 @@
+import { context } from '@ember/-internals/environment';
+
+(function () {
+  let Ember;
+
+  function defineEmber(key) {
+    Object.defineProperty(context.exports, key, {
+      enumerable: true,
+      configurable: true,
+      get() {
+        if (!Ember) {
+          Ember = require('ember').default;
+        }
+
+        return Ember;
+      },
+    });
+  }
+
+  // Bootstrap the global
+  defineEmber('Ember');
+  defineEmber('Em');
+
+  // Bootstrap Node module
+  // eslint-disable-next-line no-undef
+  if (typeof module === 'object' && typeof module.require === 'function') {
+    // eslint-disable-next-line no-undef
+    module.exports = Ember = require('ember').default;
+  }
+})();

packages/@ember/-internals/environment/lib/global.ts

@@ -1,4 +1,4 @@
-/* globals global, window, self, mainContext */
+/* globals global, window, self */
 declare const mainContext: object | undefined;
 
 // from lodash to catch fake globals

packages/ember-template-compiler/index.ts

@@ -1,24 +1,27 @@
-import { context, ENV } from '@ember/-internals/environment';
+import { ENV } from '@ember/-internals/environment';
 import { FEATURES } from '@ember/canary-features';
 import VERSION from 'ember/version';
 
-export const _Ember =
-  (typeof (context.imports as any).Ember === 'object' && (context.imports as any).Ember) || {};
+declare global {
+  interface NodeRequire {
+    has(name: string): boolean;
+  }
 
-// private API used by ember-cli-htmlbars to setup ENV and FEATURES
-if (!_Ember.ENV) {
-  _Ember.ENV = ENV;
-}
-if (!_Ember.FEATURES) {
-  _Ember.FEATURES = FEATURES;
-}
-if (!_Ember.VERSION) {
-  _Ember.VERSION = VERSION;
+  function define(path: string, deps: string[], module: () => void): void;
 }
 
-// used for adding Ember.Handlebars.compile for backwards compat
-import setupGlobal from './lib/compat';
-setupGlobal(_Ember);
+export let _Ember: unknown;
+
+try {
+  // tslint:disable-next-line: no-require-imports
+  _Ember = require('ember');
+} catch (e) {
+  _Ember = {
+    ENV,
+    FEATURES,
+    VERSION,
+  };
+}
 
 export { default as precompile } from './lib/system/precompile';
 export { default as compile } from './lib/system/compile';

packages/ember-template-compiler/lib/system/compile.ts

@@ -1,7 +1,6 @@
 /**
 @module ember
 */
-import require, { has } from 'require';
 import { EmberPrecompileOptions } from '../types';
 import precompile from './precompile';
 
@@ -23,7 +22,7 @@ export default function compile(
   templateString: string,
   options: Partial<EmberPrecompileOptions> = {}
 ): Factory {
-  if (!template && has('@ember/-internals/glimmer')) {
+  if (!template && require.has('@ember/-internals/glimmer')) {
     // tslint:disable-next-line:no-require-imports
     template = require('@ember/-internals/glimmer').template;
   }

packages/ember-template-compiler/lib/system/initializer.ts

@@ -1,11 +1,10 @@
-import require, { has } from 'require';
 import bootstrap from './bootstrap';
 
 // Globals mode template compiler
 if (
-  has('@ember/application') &&
-  has('@ember/-internals/browser-environment') &&
-  has('@ember/-internals/glimmer')
+  require.has('@ember/application') &&
+  require.has('@ember/-internals/browser-environment') &&
+  require.has('@ember/-internals/glimmer')
 ) {
   // tslint:disable:no-require-imports
   let emberEnv = require('@ember/-internals/browser-environment');

packages/ember/index.d.ts

@@ -0,0 +1,5 @@
+declare module 'ember' {
+  declare const Ember: any;
+
+  export default Ember;
+}

packages/ember/index.js

@@ -1,7 +1,4 @@
-import require, { has } from 'require';
-
-import { getENV, getLookup, setLookup, ENV, context } from '@ember/-internals/environment';
-import { IS_NODE, module } from 'node-module';
+import { getENV, getLookup, setLookup, ENV } from '@ember/-internals/environment';
 import * as utils from '@ember/-internals/utils';
 import { Registry, Container } from '@ember/-internals/container';
 import * as instrumentation from '@ember/instrumentation';
@@ -168,7 +165,7 @@ import {
 
 // ****@ember/-internals/environment****
 
-const Ember = (typeof context.imports.Ember === 'object' && context.imports.Ember) || {};
+const Ember = {};
 
 import { isIE } from '@ember/-internals/browser-environment';
 
@@ -782,13 +779,27 @@ runLoadHooks('Ember.Application', Application);
 Ember.DataAdapter = extensionSupport.DataAdapter;
 Ember.ContainerDebugAdapter = extensionSupport.ContainerDebugAdapter;
 
-if (has('ember-template-compiler')) {
-  require('ember-template-compiler');
+if (require.has('ember-template-compiler')) {
+  let templateCompiler = require('ember-template-compiler');
+
+  let EmberHandlebars = Ember.Handlebars;
+  if (!EmberHandlebars) {
+    Ember.Handlebars = EmberHandlebars = {};
+  }
+
+  let EmberHTMLBars = Ember.HTMLBars;
+  if (!EmberHTMLBars) {
+    Ember.HTMLBars = EmberHTMLBars = {};
+  }
+
+  EmberHTMLBars.precompile = EmberHandlebars.precompile = templateCompiler.precompile;
+  EmberHTMLBars.compile = EmberHandlebars.compile = templateCompiler.compile;
+  EmberHTMLBars.registerPlugin = templateCompiler.registerPlugin;
 }
 
 // do this to ensure that Ember.Test is defined properly on the global
 // if it is present.
-if (has('ember-testing')) {
+if (require.has('ember-testing')) {
   let testing = require('ember-testing');
 
   Ember.Test = testing.Test;
@@ -799,13 +810,13 @@ if (has('ember-testing')) {
 
 runLoadHooks('Ember');
 
-export default Ember;
+Ember.__loader = {
+  require,
+  define,
+  registry: require._eak_seen,
+};
 
-if (IS_NODE) {
-  module.exports = Ember;
-} else {
-  context.exports.Ember = context.exports.Em = Ember;
-}
+export default Ember;
 
 /**
  @module jquery

packages/ember/tests/reexports_test.js

@@ -1,5 +1,4 @@
 import Ember from '../index';
-import require from 'require';
 import {
   FEATURES,
   EMBER_GLIMMER_HELPER_MANAGER,

packages/internal-test-helpers/lib/confirm-export.js

@@ -1,5 +1,3 @@
-import require from 'require';
-
 function getDescriptor(obj, path) {
   let parts = path.split('.');
   let value = obj;

packages/internal-test-helpers/lib/ember-dev/setup-qunit.ts

@@ -1,3 +1,5 @@
+import Ember from 'ember';
+
 import { getDebugFunction, setDebugFunction } from '@ember/debug';
 import { DEBUG } from '@glimmer/env';