[FEATURE modernized-built-in-components] Remaining implementation work

packages/@ember/-internals/glimmer/index.ts

@@ -366,9 +366,10 @@ export { templateFactory as template, templateCacheCounters } from '@glimmer/opc
 export { default as RootTemplate } from './lib/templates/root';
 export { default as Checkbox } from './lib/components/checkbox';
 export { default as TextField } from './lib/components/text-field';
-export { default as TextArea } from './lib/components/textarea';
-export { default as LinkComponent } from './lib/components/link-to';
+export { default as TextArea } from './lib/components/-textarea';
+export { default as LinkComponent } from './lib/components/-link-to';
 export { default as Input } from './lib/components/input';
+export { default as Textarea } from './lib/components/textarea';
 export { default as Component } from './lib/component';
 export { default as Helper, helper } from './lib/helper';
 export { SafeString, escapeExpression, htmlSafe, isHTMLSafe } from './lib/utils/string';

packages/@ember/-internals/glimmer/lib/component-managers/curly.ts

@@ -8,6 +8,7 @@ import { assign } from '@ember/polyfills';
 import { DEBUG } from '@glimmer/env';
 import {
   Bounds,
+  CapturedArguments,
   CompilableProgram,
   Destroyable,
   ElementOperations,
@@ -178,14 +179,19 @@ export default class CurlyComponentManager
 
   prepareArgs(ComponentClass: ComponentFactory, args: VMArguments): Option<PreparedArguments> {
     if (args.named.has('__ARGS__')) {
+      assert(
+        '[BUG] cannot pass both __ARGS__ and positional arguments',
+        args.positional.length === 0
+      );
+
       let { __ARGS__, ...rest } = args.named.capture();
 
+      // does this need to be untracked?
+      let __args__ = valueForRef(__ARGS__) as CapturedArguments;
+
       let prepared = {
-        positional: EMPTY_POSITIONAL_ARGS,
-        named: {
-          ...rest,
-          ...(valueForRef(__ARGS__) as { [key: string]: Reference }),
-        },
+        positional: __args__.positional,
+        named: { ...rest, ...__args__.named },
       };
 
       return prepared;

packages/@ember/-internals/glimmer/lib/component.ts

@@ -1,6 +1,6 @@
 import { get, PROPERTY_DID_CHANGE } from '@ember/-internals/metal';
 import { getOwner } from '@ember/-internals/owner';
-import { TargetActionSupport } from '@ember/-internals/runtime';
+import { CoreObject, TargetActionSupport } from '@ember/-internals/runtime';
 import {
   ActionSupport,
   ChildViewsSupport,
@@ -10,6 +10,7 @@ import {
   ViewMixin,
   ViewStateSupport,
 } from '@ember/-internals/views';
+import { EMBER_MODERNIZED_BUILT_IN_COMPONENTS } from '@ember/canary-features';
 import { assert, deprecate } from '@ember/debug';
 import { DEBUG } from '@glimmer/env';
 import { setInternalComponentManager } from '@glimmer/manager';
@@ -1065,4 +1066,65 @@ Component.reopenClass({
 
 setInternalComponentManager(CURLY_COMPONENT_MANAGER, Component);
 
+if (EMBER_MODERNIZED_BUILT_IN_COMPONENTS) {
+  Object.defineProperty(Component, '_wasReopened', {
+    configurable: true,
+    enumerable: false,
+    writable: true,
+    value: false,
+  });
+
+  Object.defineProperty(Component, 'reopen', {
+    configurable: true,
+    enumerable: false,
+    writable: true,
+    value: function reopen(this: typeof Component, ...args: unknown[]): unknown {
+      if (this === Component) {
+        deprecate(
+          'Reopening the Ember.Component super class itself is deprecated. ' +
+            'Consider alternatives such as installing event listeners on ' +
+            'the document or add the customizations to specific subclasses.',
+          false,
+          {
+            id: 'ember.component.reopen',
+            for: 'ember-source',
+            since: {},
+            until: '4.0.0',
+          }
+        );
+
+        Component._wasReopened = true;
+      }
+
+      return CoreObject.reopen.call(this, ...args);
+    },
+  });
+
+  Object.defineProperty(Component, 'reopenClass', {
+    configurable: true,
+    enumerable: false,
+    writable: true,
+    value: function reopenClass(this: typeof Component, ...args: unknown[]): unknown {
+      if (this === Component) {
+        deprecate(
+          'Reopening the Ember.Component super class itself is deprecated. ' +
+            'Consider alternatives such as installing event listeners on ' +
+            'the document or add the customizations to specific subclasses.',
+          false,
+          {
+            id: 'ember.component.reopen',
+            for: 'ember-source',
+            since: {},
+            until: '4.0.0',
+          }
+        );
+
+        Component._wasReopened = true;
+      }
+
+      return CoreObject.reopenClass.call(this, ...args);
+    },
+  });
+}
+
 export default Component;