From 0c1fe72dcf1d688fabf3b2b420dbe08da116a2ca Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Mon, 17 Feb 2020 11:02:15 -0500
Subject: [PATCH] build: make watch tree-shakable in lean build

---
 packages/runtime-core/src/componentProxy.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/runtime-core/src/componentProxy.ts b/packages/runtime-core/src/componentProxy.ts
index 5d8d4364..b2ff4baa 100644
--- a/packages/runtime-core/src/componentProxy.ts
+++ b/packages/runtime-core/src/componentProxy.ts
@@ -1,7 +1,7 @@
 import { ComponentInternalInstance, Data, Emit } from './component'
 import { nextTick, queueJob } from './scheduler'
 import { instanceWatch } from './apiWatch'
-import { EMPTY_OBJ, hasOwn, isGloballyWhitelisted } from '@vue/shared'
+import { EMPTY_OBJ, hasOwn, isGloballyWhitelisted, NOOP } from '@vue/shared'
 import {
   ExtractComputedReturns,
   ComponentOptionsBase,
@@ -63,7 +63,7 @@ const publicPropertiesMap: Record<
   $options: i => i.type,
   $forceUpdate: i => () => queueJob(i.update),
   $nextTick: () => nextTick,
-  $watch: i => instanceWatch.bind(i)
+  $watch: __FEATURE_OPTIONS__ ? i => instanceWatch.bind(i) : NOOP
 }
 
 const enum AccessTypes {