[BUGFIX release] Restore previous hash behavior

Restores the previous hash behavior where `hash` will lazily update in
templates, but eagerly evaluate and create a POJO in JS. Also preserves
the deprecation on setting on the hash.

package.json

@@ -50,7 +50,7 @@
     "@babel/helper-module-imports": "^7.8.3",
     "@babel/plugin-transform-block-scoping": "^7.8.3",
     "@ember/edition-utils": "^1.2.0",
-    "@glimmer/vm-babel-plugins": "0.79.4",
+    "@glimmer/vm-babel-plugins": "0.80.0",
     "babel-plugin-debug-macros": "^0.3.3",
     "babel-plugin-filter-imports": "^4.0.0",
     "broccoli-concat": "^4.2.4",
@@ -75,19 +75,19 @@
   },
   "devDependencies": {
     "@babel/preset-env": "^7.9.5",
-    "@glimmer/compiler": "0.79.4",
-    "@glimmer/destroyable": "0.79.4",
+    "@glimmer/compiler": "0.80.0",
+    "@glimmer/destroyable": "0.80.0",
     "@glimmer/env": "^0.1.7",
-    "@glimmer/global-context": "0.79.4",
-    "@glimmer/interfaces": "0.79.4",
-    "@glimmer/manager": "0.79.4",
-    "@glimmer/node": "0.79.4",
-    "@glimmer/opcode-compiler": "0.79.4",
+    "@glimmer/global-context": "0.80.0",
+    "@glimmer/interfaces": "0.80.0",
+    "@glimmer/manager": "0.80.0",
+    "@glimmer/node": "0.80.0",
+    "@glimmer/opcode-compiler": "0.80.0",
     "@glimmer/owner": "0.80.0",
-    "@glimmer/program": "0.79.4",
-    "@glimmer/reference": "0.79.4",
-    "@glimmer/runtime": "0.79.4",
-    "@glimmer/validator": "0.79.4",
+    "@glimmer/program": "0.80.0",
+    "@glimmer/reference": "0.80.0",
+    "@glimmer/runtime": "0.80.0",
+    "@glimmer/validator": "0.80.0",
     "@simple-dom/document": "^1.4.0",
     "@types/qunit": "^2.11.1",
     "@types/rsvp": "^4.0.3",

packages/@ember/-internals/glimmer/tests/integration/helpers/hash-test.js

@@ -255,7 +255,10 @@ moduleFor(
 
       runTask(() => {
         set(this.context, 'firstName', 'Godfrey');
+      });
 
+      // needs to be separate task because of the way classic components update args
+      runTask(() => {
         expectDeprecation(() => {
           set(instance.hash, 'lastName', 'Chan');
         }, /You set the '.*' property on a {{hash}} object/);

packages/@ember/-internals/metal/lib/chain-tags.ts

@@ -1,7 +1,6 @@
 import { Meta, meta as metaFor, peekMeta } from '@ember/-internals/meta';
 import { isObject } from '@ember/-internals/utils';
 import { assert, deprecate } from '@ember/debug';
-import { isHashProxy } from '@glimmer/runtime';
 import { _WeakSet } from '@glimmer/util';
 import {
   combine,
@@ -17,7 +16,7 @@ import { tagForProperty } from './tags';
 
 export const CHAIN_PASS_THROUGH = new _WeakSet();
 
-export function finishLazyChains(meta: Meta, key: string, value: unknown): void {
+export function finishLazyChains(meta: Meta, key: string, value: any) {
   let lazyTags = meta.readableLazyChainsFor(key);
 
   if (lazyTags === undefined) {
@@ -174,6 +173,20 @@ function getChainTags(
 
     chainTags.push(propertyTag);
 
+    // If we're at the end of the path, processing the last segment, and it's
+    // not an alias, we should _not_ get the last value, since we already have
+    // its tag. There's no reason to access it and do more work.
+    if (segmentEnd === pathLength) {
+      // If the key was an alias, we should always get the next value in order to
+      // bootstrap the alias. This is because aliases, unlike other CPs, should
+      // always be in sync with the aliased value.
+      if (CHAIN_PASS_THROUGH.has(descriptor)) {
+        // tslint:disable-next-line: no-unused-expression
+        current[segment];
+      }
+      break;
+    }
+
     if (descriptor === undefined) {
       // If the descriptor is undefined, then its a normal property, so we should
       // lookup the value to chain off of like normal.
@@ -210,16 +223,8 @@ function getChainTags(
       }
     }
 
-    if (segmentEnd === pathLength || !isObject(current)) {
+    if (!isObject(current)) {
       // we've hit the end of the chain for now, break out
-
-      // If the last value is a HashProxy, then entangle all of its tags
-      if (isHashProxy(current)) {
-        for (let key in current) {
-          chainTags.push(tagForProperty(current, key));
-        }
-      }
-
       break;
     }