From caa9297da6ce828e62a17b07303cd761632a5074 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=89=A9=E6=95=A3=E6=80=A7=E7=99=BE=E4=B8=87=E7=94=9C?=
 =?UTF-8?q?=E9=9D=A2=E5=8C=85?= <himself65@outlook.com>
Date: Sun, 6 Oct 2019 03:48:05 +0800
Subject: [PATCH] refactor: move writable check out of computed setter (#112)

---
 packages/reactivity/src/computed.ts | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/packages/reactivity/src/computed.ts b/packages/reactivity/src/computed.ts
index 9ed42716..3bb3c3e2 100644
--- a/packages/reactivity/src/computed.ts
+++ b/packages/reactivity/src/computed.ts
@@ -28,7 +28,9 @@ export function computed<T>(
     ? (getterOrOptions as (() => T))
     : (getterOrOptions as WritableComputedOptions<T>).get
   const setter = isReadonly
-    ? null
+    ? () => {
+        // TODO warn attempting to mutate readonly computed value
+      }
     : (getterOrOptions as WritableComputedOptions<T>).set
 
   let dirty: boolean = true
@@ -57,12 +59,8 @@ export function computed<T>(
       trackChildRun(runner)
       return value
     },
-    set value(newValue) {
-      if (setter) {
-        setter(newValue)
-      } else {
-        // TODO warn attempting to mutate readonly computed value
-      }
+    set value(newValue: T) {
+      setter(newValue)
     }
   }
 }