Vue.js 不会告诉我错误的行号

Question

第 8 行和第 23 行没有调用length为什么 vue 不告诉我错误的行号？

    vue.runtime.esm.js?2b0e:619 [Vue warn]: Error in render: "TypeError: Cannot read property 'length' of undefined"

found in

---> <IsoDeals> at src/views/iso/Deals.vue
       <VContent>
         <VApp>
           <App> at src/App.vue
             <Root>

vue.runtime.esm.js?2b0e:1888 TypeError: Cannot read property 'length' of undefined
    at Proxy.render (eval at ./node_modules/cache-loader/dist/cjs.js?{"cacheDirectory":"node_modules/.cache/vue-loader","cacheIdentifier":"1c8c67b2-vue-loader-template"}!./node_modules/vue-loader/lib/loaders/templateLoader.js?!./node_modules/vuetify-loader/lib/loader.js?!./node_modules/cache-loader/dist/cjs.js?!./node_modules/vue-loader/lib/index.js?!./src/views/iso/Deals.vue?vue&type=template&id=13ff2f9a&scoped=true& (8.js:23), <anonymous>:235:70)
    at VueComponent.Vue._render (vue.runtime.esm.js?2b0e:3548)
    at VueComponent.updateComponent (vue.runtime.esm.js?2b0e:4066)
    at Watcher.get (vue.runtime.esm.js?2b0e:4479)
    at new Watcher (vue.runtime.esm.js?2b0e:4468)
    at mountComponent (vue.runtime.esm.js?2b0e:4073)
    at VueComponent.Vue.$mount (vue.runtime.esm.js?2b0e:8415)
    at init (vue.runtime.esm.js?2b0e:3118)
    at merged (vue.runtime.esm.js?2b0e:3301)
    at createComponent (vue.runtime.esm.js?2b0e:5978)

我发现这是出错的代码。第 16 - 26 行。leads.length在第 24 行被调用。那么为什么 vue 不告诉我这些行号？

          <v-data-table
            :headers="leadHeaders"
            :items="leads"
            :items-per-page-options="[
              10,
              20,
              { text: '$vuetify.dataIterator.rowsPerPageAll', value: -1 }
            ]"
            :hide-default-footer="leads.length < 10"
            class="elevation-1"
          >

Answer 1

为什么 vue 不告诉我错误的行号？

因为它不受支持，至少在版本 2 中。请密切关注版本 3；在计算源地图的方式上有一些改进。