From da498d7aa5f64ee4f1bb14a2191a295e85f6b19d Mon Sep 17 00:00:00 2001
From: Scott Newcomer <snewcomer24@gmail.com>
Date: Tue, 9 Jun 2020 22:06:47 -0500
Subject: [PATCH] [Chore]: Add integration test for accessing a property during
 init

---
 .../integration/components/tracked-test.js    | 52 ++++++++++++++++++-
 .../runtime/lib/system/core_object.js         |  2 +
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/packages/@ember/-internals/glimmer/tests/integration/components/tracked-test.js b/packages/@ember/-internals/glimmer/tests/integration/components/tracked-test.js
index 10a5f5b9c97..a6342af3e9c 100644
--- a/packages/@ember/-internals/glimmer/tests/integration/components/tracked-test.js
+++ b/packages/@ember/-internals/glimmer/tests/integration/components/tracked-test.js
@@ -1,6 +1,12 @@
 import { Object as EmberObject, A, ArrayProxy, PromiseProxyMixin } from '@ember/-internals/runtime';
 import { EMBER_CUSTOM_COMPONENT_ARG_PROXY } from '@ember/canary-features';
-import { computed, get, tracked, nativeDescDecorator as descriptor } from '@ember/-internals/metal';
+import {
+  computed,
+  get,
+  set,
+  tracked,
+  nativeDescDecorator as descriptor,
+} from '@ember/-internals/metal';
 import { Promise } from 'rsvp';
 import { moduleFor, RenderingTestCase, strip, runTask } from 'internal-test-helpers';
 import GlimmerishComponent from '../../utils/glimmerish-component';
@@ -493,6 +499,50 @@ moduleFor(
       // check to make sure we can still mutate the person
       person.first = 'max';
     }
+
+    '@test works when EmberObject created during render'() {
+      this.registerComponent('test', {
+        ComponentClass: class extends GlimmerishComponent {},
+        template: '{{@data.length}}',
+      });
+
+      let RecordMeta = new WeakMap();
+      function getRecordMeta(record) {
+        let meta = RecordMeta.get(record);
+        if (meta === undefined) {
+          meta = Object.create(null);
+          RecordMeta.set(record, meta);
+        }
+
+        return meta;
+      }
+
+      // does not reproduce with native JS class only
+      class Person extends EmberObject {
+        get name() {
+          let meta = getRecordMeta(this);
+          let name = get(meta, 'name');
+          return name;
+        }
+        set name(v) {
+          let meta = getRecordMeta(this);
+          set(meta, 'name', v);
+        }
+      }
+
+      class List {
+        get records() {
+          let p = Person.create({ name: 'ye-haw' });
+          return [p];
+        }
+      }
+
+      this.render('<Test @data={{this.data.records}} />', {
+        data: new List(),
+      });
+
+      this.assertText('1');
+    }
   }
 );
 
diff --git a/packages/@ember/-internals/runtime/lib/system/core_object.js b/packages/@ember/-internals/runtime/lib/system/core_object.js
index 186a52c6f8f..884ca8feaca 100644
--- a/packages/@ember/-internals/runtime/lib/system/core_object.js
+++ b/packages/@ember/-internals/runtime/lib/system/core_object.js
@@ -105,6 +105,7 @@ function initialize(obj, properties) {
         let baseValue = obj[keyName];
 
         if (hasConcatenatedProps && concatenatedProperties.indexOf(keyName) > -1) {
+          let baseValue = obj[keyName];
           if (baseValue) {
             value = makeArray(baseValue).concat(value);
           } else {
@@ -113,6 +114,7 @@ function initialize(obj, properties) {
         }
 
         if (hasMergedProps && mergedProperties.indexOf(keyName) > -1) {
+          let baseValue = obj[keyName];
           value = assign({}, baseValue, value);
         }
       }