From d179918001e7bf88b0701ab73f982ca1e7626781 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Thu, 17 Oct 2019 22:29:51 -0400
Subject: [PATCH] perf: further tweak accessCache

---
 packages/runtime-core/src/component.ts      | 2 +-
 packages/runtime-core/src/componentProxy.ts | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/packages/runtime-core/src/component.ts b/packages/runtime-core/src/component.ts
index 9b1fe8a8..5e8539b8 100644
--- a/packages/runtime-core/src/component.ts
+++ b/packages/runtime-core/src/component.ts
@@ -258,7 +258,7 @@ export function setupStatefulComponent(
     }
   }
   // 0. create render proxy property access cache
-  instance.accessCache = Object.create(null)
+  instance.accessCache = {}
   // 1. create render proxy
   instance.renderProxy = new Proxy(instance, PublicInstanceProxyHandlers)
   // 2. create props proxy
diff --git a/packages/runtime-core/src/componentProxy.ts b/packages/runtime-core/src/componentProxy.ts
index bc1a1f54..87fa22ec 100644
--- a/packages/runtime-core/src/componentProxy.ts
+++ b/packages/runtime-core/src/componentProxy.ts
@@ -56,7 +56,7 @@ const enum AccessTypes {
 
 export const PublicInstanceProxyHandlers: ProxyHandler<any> = {
   get(target: ComponentInternalInstance, key: string) {
-    const { renderContext, data, props, propsProxy, accessCache } = target
+    const { renderContext, data, props, propsProxy, accessCache, type } = target
     // This getter gets called for every property access on the render context
     // during render and is a major hotspot. The most expensive part of this
     // is the multiple hasOwn() calls. It's much faster to do a simple property
@@ -79,7 +79,10 @@ export const PublicInstanceProxyHandlers: ProxyHandler<any> = {
       accessCache[key] = AccessTypes.CONTEXT
       return renderContext[key]
     } else if (hasOwn(props, key)) {
-      accessCache[key] = AccessTypes.PROPS
+      // only cache props access if component has declared (thus stable) props
+      if (type.props != null) {
+        accessCache[key] = AccessTypes.PROPS
+      }
       // return the value from propsProxy for ref unwrapping and readonly
       return propsProxy![key]
     } else if (key === '$el') {