Fix addUnitPx can not convert rpx to px (#361)

packages/core/src/utils/format/unit.ts

@@ -1,5 +1,6 @@
 import * as _ from "lodash"
 import { CSSProperties } from "react"
+import { getSystemInfoSync } from "@tarojs/taro"
 
 export function addUnitPx(value?: string | number): string {
   return value === undefined ? "" : `${unitToPx(value)}px`
@@ -38,6 +39,12 @@ function getRootFontSize() {
   return rootFontSize
 }
 
+function convertRpx(value: string) {
+  value = value.replace(/rpx/g, "")
+  const pixelRatio = 750 / getSystemInfoSync().windowWidth
+  return +value / pixelRatio
+}
+
 function convertPx(value: string) {
   value = value.replace(/px/g, "")
   return +value
@@ -63,6 +70,9 @@ export function unitToPx(value: string | number): number {
     return value
   }
 
+  if (value.includes("rpx")) {
+    return convertRpx(value)
+  }
   if (value.includes("px")) {
     return convertPx(value)
   }