perf(reactivity): only call Set.add if doesn't already have value (#3307)

2021-02-26 03:57:35 +08:00 · 2021-02-26 03:57:35 +08:00 · 9cd988342c
commit 9cd988342c
parent 5ad4036e29
1 changed files with 1 additions and 1 deletions
--- a/packages/reactivity/src/collectionHandlers.ts
+++ b/packages/reactivity/src/collectionHandlers.ts
@ -76,8 +76,8 @@ function add(this: SetTypes, value: unknown) {
  const target = toRaw(this)
  const proto = getProto(target)
  const hadKey = proto.has.call(target, value)
-  target.add(value)
  if (!hadKey) {
+    target.add(value)
    trigger(target, TriggerOpTypes.ADD, value, value)
  }
  return this