Vue.js 一些 errors/warnings 很难调试

Question

当运行一个 Vue.js 应用程序时，我在控制台中收到一条警告，我无法确定它来自哪里（在源代码中），或者至少无法确定它来自哪个组件。

控制台输出如下：

    TypeError: Cannot read property 'length' of undefined
        at _c.attrs.rules (eval at ./node_modules/vue-loader/lib/template-compiler/index.js?{"id":"data-v-012a975a","hasScoped":true,"optionsId":"0","buble":{"transforms":{}}}!./node_modules/vue-loader/lib/selector.js?type=template&index=0!./src/components/Contact_Form.vue (0.js:300), <anonymous>:252:41)
        at VueComponent.validate (vuetify.js?dc48:8564)
        at VueComponent.mounted (vuetify.js?dc48:8535)
        at callHook (vue.runtime.esm.js?ff9b:2917)
        at insert (vue.runtime.esm.js?ff9b:4154)
        at Object.invoker [as insert] (vue.runtime.esm.js?ff9b:2019)
        at invokeInsertHook (vue.runtime.esm.js?ff9b:5956)
        at VueComponent.patch [as __patch__] (vue.runtime.esm.js?ff9b:6175)
        at VueComponent.Vue._update (vue.runtime.esm.js?ff9b:2666)
        at VueComponent.updateComponent (vue.runtime.esm.js?ff9b:2784)

        logError    @   vue.runtime.esm.js?ff9b:1737
        globalHandleError   @   vue.runtime.esm.js?ff9b:1728
        handleError @   vue.runtime.esm.js?ff9b:1717
        callHook    @   vue.runtime.esm.js?ff9b:2919
        insert  @   vue.runtime.esm.js?ff9b:4154
        invoker @   vue.runtime.esm.js?ff9b:2019
        invokeInsertHook    @   vue.runtime.esm.js?ff9b:5956
        patch   @   vue.runtime.esm.js?ff9b:6175
        Vue._update @   vue.runtime.esm.js?ff9b:2666
        updateComponent @   vue.runtime.esm.js?ff9b:2784
        get @   vue.runtime.esm.js?ff9b:3138
        run @   vue.runtime.esm.js?ff9b:3215
        flushSchedulerQueue @   vue.runtime.esm.js?ff9b:2977
        (anonymous) @   vue.runtime.esm.js?ff9b:1833
        flushCallbacks  @   vue.runtime.esm.js?ff9b:1754
        Promise.then (async)        
        microTimerFunc  @   vue.runtime.esm.js?ff9b:1802
        nextTick    @   vue.runtime.esm.js?ff9b:1846
        queueWatcher    @   vue.runtime.esm.js?ff9b:3064
        update  @   vue.runtime.esm.js?ff9b:3205
        notify  @   vue.runtime.esm.js?ff9b:693
        reactiveSetter  @   vue.runtime.esm.js?ff9b:1010
        (anonymous) @   vue-router.esm.js?fe87:2508
        (anonymous) @   vue-router.esm.js?fe87:2507
        updateRoute @   vue-router.esm.js?fe87:1997
        (anonymous) @   vue-router.esm.js?fe87:1875
        (anonymous) @   vue-router.esm.js?fe87:1984
        step    @   vue-router.esm.js?fe87:1714
        step    @   vue-router.esm.js?fe87:1721
        runQueue    @   vue-router.esm.js?fe87:1725
        (anonymous) @   vue-router.esm.js?fe87:1979
        step    @   vue-router.esm.js?fe87:1714
        (anonymous) @   vue-router.esm.js?fe87:1718
        (anonymous) @   vue-router.esm.js?fe87:1964
        (anonymous) @   vue-router.esm.js?fe87:1757
        (anonymous) @   vue-router.esm.js?fe87:1833
        Promise.then (async)        
        (anonymous) @   vue-router.esm.js?fe87:1780
        (anonymous) @   vue-router.esm.js?fe87:1801
        (anonymous) @   vue-router.esm.js?fe87:1801
        flatMapComponents   @   vue-router.esm.js?fe87:1800
        (anonymous) @   vue-router.esm.js?fe87:1736
        iterator    @   vue-router.esm.js?fe87:1943
        step    @   vue-router.esm.js?fe87:1717
        step    @   vue-router.esm.js?fe87:1721
        runQueue    @   vue-router.esm.js?fe87:1725
        confirmTransition   @   vue-router.esm.js?fe87:1972
        transitionTo    @   vue-router.esm.js?fe87:1874
        init    @   vue-router.esm.js?fe87:2494
        beforeCreate    @   vue-router.esm.js?fe87:540
        callHook    @   vue.runtime.esm.js?ff9b:2917
        Vue._init   @   vue.runtime.esm.js?ff9b:4622
        Vue @   vue.runtime.esm.js?ff9b:4725
        (anonymous) @   main.js?1c90:48
        ./src/main.js   @   app.js:1735
        __webpack_require__ @   app.js:708
        fn  @   app.js:113
        0   @   app.js:1813
        __webpack_require__ @   app.js:708
        (anonymous) @   app.js:806
        (anonymous) @   app.js:809

Answer 1

来自./src/components/Contact_Form.vue

看第二行

Vue.js 一些 errors/warnings 很难调试

Vue.js some errors/warnings are quite difficult to debug

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vuetify.js

vee-validate