Address review feedback.

lit · Oct 22, 2022 · 2bd819e · 2bd819e
1 parent 49090db
commit 2bd819e
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Showing 2 changed files with 9 additions and 4 deletions.
diff --git a/.changeset/blue-olives-fetch.md b/.changeset/blue-olives-fetch.md
@@ -0,0 +1,5 @@
+---
+'@lit/reactive-element': patch
+---
+
+Initializers added to subclasses are no longer improperly added to superclass.
diff --git a/packages/reactive-element/src/reactive-element.ts b/packages/reactive-element/src/reactive-element.ts
@@ -491,8 +491,7 @@ export abstract class ReactiveElement
    */
   static addInitializer(initializer: Initializer) {
     this.finalize();
-    this._initializers ??= [];
-    this._initializers!.push(initializer);
+    (this._initializers ??= []).push(initializer);
   }
 
   static _initializers?: Initializer[];
@@ -764,8 +763,9 @@ export abstract class ReactiveElement
     const superCtor = Object.getPrototypeOf(this) as typeof ReactiveElement;
     superCtor.finalize();
     // Create own set of initializers for this class if any exist on the
-    // superclass and copy them down.
-    if (superCtor._initializers) {
+    // superclass and copy them down. Note, for a small perf boost, avoid
+    // creating initializers unless needed.
+    if (superCtor._initializers !== undefined) {
       this._initializers = [...superCtor._initializers];
     }
     this.elementProperties = new Map(superCtor.elementProperties);