From fdb1296eb573f628739194b0f0e481c66177c581 Mon Sep 17 00:00:00 2001
From: Chris Garrett <cgarrett@linkedin.com>
Date: Tue, 13 Oct 2020 14:43:16 -0700
Subject: [PATCH] [BUGFIX] Asserts when users attempt to set a shadowed value
 with Ember.set

---
 .../-internals/metal/lib/property_set.ts      | 19 ++++++++++++++++++-
 .../@ember/-internals/metal/lib/tracked.ts    |  6 +++---
 .../metal/tests/tracked/set_test.js           | 16 ++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/packages/@ember/-internals/metal/lib/property_set.ts b/packages/@ember/-internals/metal/lib/property_set.ts
index aef085266ed..ee757f76a2f 100644
--- a/packages/@ember/-internals/metal/lib/property_set.ts
+++ b/packages/@ember/-internals/metal/lib/property_set.ts
@@ -1,4 +1,9 @@
-import { HAS_NATIVE_PROXY, setWithMandatorySetter, toString } from '@ember/-internals/utils';
+import {
+  HAS_NATIVE_PROXY,
+  lookupDescriptor,
+  setWithMandatorySetter,
+  toString,
+} from '@ember/-internals/utils';
 import { assert } from '@ember/debug';
 import EmberError from '@ember/error';
 import { DEBUG } from '@glimmer/env';
@@ -70,6 +75,18 @@ export function set(obj: object, keyName: string, value: any, tolerant?: boolean
   let descriptor = descriptorForProperty(obj, keyName);
 
   if (descriptor !== undefined) {
+    if (DEBUG) {
+      let instanceDesc = lookupDescriptor(obj, keyName);
+      let name = instanceDesc?.set?.toString();
+
+      assert(
+        `Attempted to set \`${toString(
+          obj
+        )}.${keyName}\` using Ember.set(), but the property was a computed or tracked property that was shadowed by another property declaration. This can happen if you defined a tracked or computed property on a parent class, and then redefined it on a subclass.`,
+        name && (name.indexOf('CPSETTER_FUNCTION') !== -1 || name.indexOf('TRACKED_SETTER') !== -1)
+      );
+    }
+
     descriptor.set(obj, keyName, value);
     return value;
   }
diff --git a/packages/@ember/-internals/metal/lib/tracked.ts b/packages/@ember/-internals/metal/lib/tracked.ts
index e7399ead097..a0b450647e4 100644
--- a/packages/@ember/-internals/metal/lib/tracked.ts
+++ b/packages/@ember/-internals/metal/lib/tracked.ts
@@ -168,7 +168,7 @@ function descriptorForField([target, key, desc]: [
     return value;
   }
 
-  function set(this: object, newValue: unknown): void {
+  function TRACKED_SETTER(this: object, newValue: unknown): void {
     setter(this, newValue);
     dirtyTagFor(this, SELF_TAG);
   }
@@ -179,10 +179,10 @@ function descriptorForField([target, key, desc]: [
     isTracked: true,
 
     get,
-    set,
+    set: TRACKED_SETTER,
   };
 
-  metaFor(target).writeDescriptors(key, new TrackedDescriptor(get, set));
+  metaFor(target).writeDescriptors(key, new TrackedDescriptor(get, TRACKED_SETTER));
 
   return newDesc;
 }
diff --git a/packages/@ember/-internals/metal/tests/tracked/set_test.js b/packages/@ember/-internals/metal/tests/tracked/set_test.js
index 5b9eaa9a84d..dde2fb3fdc7 100644
--- a/packages/@ember/-internals/metal/tests/tracked/set_test.js
+++ b/packages/@ember/-internals/metal/tests/tracked/set_test.js
@@ -31,5 +31,21 @@ moduleFor(
         assert.equal(get(newObj, key), obj[key], 'should set value');
       }
     }
+
+    ['@test set should throw an error when setting on shadowed properties'](assert) {
+      class Obj {
+        @tracked value = 'emberjs';
+
+        constructor() {
+          Object.defineProperty(this, 'value', { writable: true, value: 'emberjs' });
+        }
+      }
+
+      let newObj = new Obj();
+
+      assert.throws(() => {
+        set(newObj, 'value', 123);
+      }, /Attempted to set `\[object Object\].value` using Ember.set\(\), but the property was a computed or tracked property that was shadowed by another property declaration. This can happen if you defined a tracked or computed property on a parent class, and then redefined it on a subclass/);
+    }
   }
 );