uni-app在渲染wxs得时候包含function会导致报错

代码如下

<template>  
    <view>  
        <view>  
            <view>{{ tools.formatTest('123333') }}</view>  
        </view>  
    </view>  
</template>  
<script module="tools" lang="wxs">  
var formatTest = function (ops) {  
    if(!ops){  
        return 'aaaa';  
    }  
     return 'bbbbbb'  
}  

module.exports = {  
    formatTest:formatTest  
}  
</script>  

<script>  
export default {  
    data() {  
        return {};  
    },  
    methods: {}  
};  
</script>  

<style></style>  

报错情况为

文件查找失败：'./wxs.vue?vue&type=template&id=441bcb6e&scoped=true&filter-modules=%7B%22tools%22%3A%7B%22type%22%3A%22script%22%2C%22content%22%3A%22var%20formatTest%20%3D%20function%20(ops)%20%7B%5Cr%5Cn%20%20%20%20if(!ops)%7B%5Cr%5Cn%20%20%20%20%20%20%20%20return%20'aaaa'%3B%5Cr%5Cn%20%20%20%20%7D%5Cr%5Cn%5Ct%5Cr%5Cn%20%20%20%20%20return%20'bbbbbb'%5Cr%5Cn%7D%5Cr%5Cn%5Cr%5Cnmodule.exports%20%3D%20%7B%5Cr%5Cn%20%20%20%20formatTest%3AformatTest%5Cr%5Cn%7D%22%2C%22start%22%3A217%2C%22attrs%22%3A%7B%22module%22%3A%22tools%22%2C%22lang%22%3A%22wxs%22%7D%2C%22end%22%3A370%7D%7D&'