fix(mp-weixin): event key (#4015)

packages/uni-mp-compiler/src/transforms/vFor.ts

@@ -63,6 +63,7 @@ export type VForOptions = Omit<ForParseResult, 'tagType'> & {
   indexCode: string
   indexExpr: Identifier | Pattern | RestElement
   indexAlias: string
+  node: ElementNode
 }
 
 export type ForElementNode = ElementNode & {
@@ -165,6 +166,7 @@ export const transformFor = createStructuralDirectiveTransform(
       indexCode,
       indexExpr,
       indexAlias,
+      node,
     }
 
     const vForScope = context.addVForScope({
@@ -237,7 +239,7 @@ function parseAlias(
   return fallback
 }
 
-function parseVForScope(currentScope: CodegenScope) {
+export function parseVForScope(currentScope: CodegenScope) {
   while (currentScope) {
     if (isVForScope(currentScope) && !isScopedSlotVFor(currentScope)) {
       return currentScope

packages/uni-mp-compiler/src/transforms/vOn.ts

@@ -23,6 +23,7 @@ import { V_ON } from '../runtimeHelpers'
 import { TransformContext } from '../transform'
 import { DirectiveTransformResult } from './transformElement'
 import { isBuiltInIdentifier, processExpression } from './transformExpression'
+import { parseVForScope } from './vFor'
 
 const fnExpRE =
   /^\s*([\w$_]+|(async\s*)?\([^)]*?\))\s*=>|^\s*(async\s+)?function(?:\s+[\w$]+)?\s*\(/
@@ -212,7 +213,13 @@ export function wrapperVOn(
   }
   const keys: string[] = []
   if (context.miniProgram.event?.key && context.inVFor) {
-    const keyProp = findProp(node, 'key')
+    let keyProp = findProp(node, 'key')
+    if (!keyProp) {
+      const vForScope = parseVForScope(context.currentScope)
+      if (vForScope) {
+        keyProp = findProp(vForScope.node, 'key')
+      }
+    }
     // 对 for 中的所有事件增加 key 标记，避免微信小程序不更新事件对象
     if (keyProp && isDirectiveNode(keyProp) && keyProp.exp) {
       const keyCode = genExpr(keyProp.exp)

packages/uni-mp-weixin/__tests__/vOn.spec.ts

@@ -23,6 +23,13 @@ describe('mp-weixin: transform v-on', () => {
       `<view wx:for="{{a}}" wx:for-item="item" wx:key="b" bindtap="{{item.c}}">{{item.a}}</view>`,
       `(_ctx, _cache) => {
   return { a: _f(_ctx.arr, (item, k0, i0) => { return { a: _t(item.text), b: item._id, c: _o($event => _ctx.show(item), item._id) }; }) }
+}`
+    )
+    assert(
+      `<view v-for="(item, index) in list" :key="item.id"><view @click="handleClickItem(item, index)"></view></view>`,
+      `<view wx:for="{{a}}" wx:for-item="item" wx:key="b"><view bindtap="{{item.a}}"></view></view>`,
+      `(_ctx, _cache) => {
+  return { a: _f(_ctx.list, (item, index, i0) => { return { a: _o($event => _ctx.handleClickItem(item, index), item.id), b: item.id }; }) }
 }`
     )
     assert(