fix(Rate): allow-half display error (#2460)

* fix(Rate): allow-half display error

* perf(Rate): remove unreachable code

packages/rate/index.ts

@@ -12,7 +12,10 @@ VantComponent({
     readonly: Boolean,
     disabled: Boolean,
     allowHalf: Boolean,
-    size: null,
+    size: {
+      type: null,
+      observer: 'setSizeWithUnit'
+    },
     icon: {
       type: String,
       value: 'star'
@@ -49,7 +52,8 @@ VantComponent({
 
   data: {
     innerValue: 0,
-    gutterWithUnit: undefined
+    gutterWithUnit: undefined,
+    sizeWithUnit: null
   },
 
   watch: {
@@ -66,6 +70,11 @@ VantComponent({
         gutterWithUnit: addUnit(val)
       });
     },
+    setSizeWithUnit(size: string | number): void {
+      this.setData({
+        sizeWithUnit: addUnit(size)
+      });
+    },
 
     onSelect(event: Weapp.Event) {
       const { data } = this;

packages/rate/index.wxml

@@ -12,8 +12,8 @@
   >
     <van-icon
       name="{{ index + 1 <= innerValue ? icon : voidIcon }}"
-      size="{{ size }}"
       class="van-rate__icon"
+      style="font-size :{{ size? sizeWithUnit : ''}}"
       custom-class="icon-class"
       data-score="{{ index }}"
       color="{{ disabled ? disabledColor : index + 1 <= innerValue ? color : voidColor }}"
@@ -22,9 +22,9 @@
 
     <van-icon
       wx:if="{{ allowHalf }}"
-      size="{{ size }}"
       name="{{ index + 0.5 <= innerValue ? icon : voidIcon }}"
       class="{{ utils.bem('rate__icon', ['half']) }}"
+      style="font-size :{{ size? sizeWithUnit : ''}}"
       custom-class="icon-class"
       data-score="{{ index - 0.5 }}"
       color="{{ disabled ? disabledColor : index + 0.5 <= innerValue ? color : voidColor }}"