[Improvement] Sku: add stepper-change event (#1349)

packages/sku/Sku.vue

@@ -77,6 +77,7 @@
           :disable-stepper-input="disableStepperInput"
           :hide-stock="hideStock"
           :custom-stepper-config="customStepperConfig"
+          @change="$emit('stepper-change', $event)"
         />
       </slot>
       <!-- sku-messages -->

packages/sku/components/SkuStepper.vue

@@ -121,6 +121,7 @@ export default create({
     onChange(currentValue) {
       const { handleStepperChange } = this.customStepperConfig;
       handleStepperChange && handleStepperChange(currentValue);
+      this.$emit('change', currentValue);
     }
   }
 });

packages/sku/en-US.md

@@ -108,6 +108,8 @@ Vue.use(Sku);
 |-----------|-----------|-----------|
 | add-cart | Triggered when click cart button | data: Object |
 | buy-clicked | Triggered when click buy button | data: Object |
+| stepper-change | Triggered when stepper value changed | value: number |
+
 
 ### Methods
 

packages/sku/zh-CN.md

@@ -109,6 +109,7 @@ Vue.use(Sku);
 |-----------|-----------|-----------|
 | add-cart | 点击添加购物车回调 | skuData: Object |
 | buy-clicked | 点击购买回调 | skuData: Object |
+| stepper-change | 购买数量变化时触发 | value: number |
 
 ### 方法