修改价格并记录

src/tool/index.js

@@ -39,5 +39,14 @@ export default {
     var cval = this.getCookie(name);
     if (cval != null)
       document.cookie = name + "=" + cval + ";expires=" + exp.toGMTString();
-  }
+  },
+  /**
+   *
+   * @param arr
+   */
+  isPurchasesValid : function (arr) {
+    return arr.every((item, index, array) =>
+       index === 0 ? true : item.purchases > array[index - 1].purchases
+    );
+  },
 }