Import vue module from another vue module in typescript

Question

Could you please help importing a TypeScript2 Vuejs2 component from another TypeScript2 Vuejs2 component?

Target module (MyTable.vue)

<script lang="ts">
export default {}
</script>

Source module (App.vue)

<template>
  <div>
    <input v-model="msg">
    <p>prop: {{propMessage}}</p>
    <p>msg: {{msg}}</p>
    <p>helloMsg: {{helloMsg}}</p>
    <p>computed msg: {{computedMsg}}</p>
    <button @click="greet">Greet</button>
     <div class="container">
      <my-vuetable></my-vuetable>
    </div>
  </div>
</template>

<script lang="ts">
import Vue from 'vue'
import Component from 'vue-class-component'
import MyVuetable from './MyTable.vue'

@Component({
  props: {
    propMessage: String
  }
})
export default class App extends Vue {
  propMessage: string

  // inital data
  msg: number = 123

  // use prop values for initial data
  helloMsg: string = 'Hello, ' + this.propMessage

  // lifecycle hook
  mounted () {
    this.greet()
  }

  // computed
  get computedMsg () {
    return 'computed ' + this.msg
  }

  // method
  greet () {
    alert('greeting: ' + this.msg)
  }
}
</script>

I am using the latest TS/Webpack/vue-loader/vue-class-component versions.

Notice that similar JS (not TS) based code is working @ https://github.com/ratiw/vuetable-2-tutorial-bootstrap

All the code is @ https://github.com/borislitvak/vue-from-vue-question

Webpack result

App.vue.d.ts  211 bytes          [emitted]
Entrypoint main = build.js build.js.map
   [0] ./~/vue/dist/vue.runtime.esm.js 175 kB {0} [depth 1] [built]
       [exports: default]
       cjs require vue [3] ./~/ts-loader!./~/vue-loader/lib/selector.js?type=script&index=0!./App.vue 19:12-26
       cjs require vue [4] ./~/vue-class-component/dist/vue-class-component.common.js 12:26-40
       cjs require vue [8] ./example.ts 3:12-26
   [1] ./~/process/browser.js 5.3 kB {0} [depth 2] [built]
       cjs require process [0] ./~/vue/dist/vue.runtime.esm.js 1:0-37
       cjs require process [4] ./~/vue-class-component/dist/vue-class-component.common.js 1:0-37
   [2] ./App.vue 1.38 kB {0} [depth 1] [built]
       cjs require ./App.vue [8] ./example.ts 4:16-36
   [3] ./~/ts-loader!./~/vue-loader/lib/selector.js?type=script&index=0!./App.vue 2.09 kB {0} [depth 2] [built]
       cjs require !!ts-loader!./node_modules/vue-loader/lib/selector?type=script&index=0!./App.vue [2] ./App.vue 3:2-93
   [4] ./~/vue-class-component/dist/vue-class-component.common.js 4.02 kB {0} [depth 3] [built]
       cjs require vue-class-component [3] ./~/ts-loader!./~/vue-loader/lib/selector.js?type=script&index=0!./App.vue 20:28-58
   [5] ./~/vue-loader/lib/component-normalizer.js 1.12 kB {0} [depth 2] [built]
       cjs require !./node_modules/vue-loader/lib/component-normalizer [2] ./App.vue 1:16-78
   [6] ./~/vue-loader/lib/template-compiler.js?id=data-v-52143112!./~/vue-loader/lib/selector.js?type=template&index=0!./App.vue 1.12 kB {0} [depth 2] [built]
       cjs require !!./node_modules/vue-loader/lib/template-compiler?id=data-v-52143112!./node_modules/vue-loader/lib/selector?type=template&index=0!./App.vue [2] ./App.vue 5:2-152
   [7] (webpack)/buildin/global.js 509 bytes {0} [depth 2] [built]
       cjs require global [0] ./~/vue/dist/vue.runtime.esm.js 1:0-44
   [8] ./example.ts 300 bytes {0} [depth 0] [built]

ERROR in ....\App.vue.ts
(20,24): error TS2307: Cannot find module './MyTable.vue'.

I am new to client side development, please help!

Thank you,

Boris

Answer 1

The answer was given by https://github.com/ktsn and the original can be found @ https://github.com/vuejs/vue/issues/5298:

This is because you don't have declarations of .vue files, then the typescript compiler cannot load them. You need to declare general declaration of .vue file in your project or generating each .vue file declaration by using vuetype

I've double checked that the above works, followed the general declaration path. Note that most vue components don't come with t.ds definitions, thus you'll have to write them yourselves for TS to be able to compile the files.

Enjoy! Boris

Answer 2

use this

module: {
    rules: [
        {
            test: /\.ts?$/,
            loader: 'ts-loader',
            options: {
                appendTsSuffixTo: [/\.vue$/]
            }
        },
        {
            test: /\.vue$/,
            loader: 'vue-loader'
        }
    ]

Answer 3

If you put the following code into a 'custom.d.ts' file at the same folder structure to where your vue files are, it should work. Boris put it beautifully and basically webpack does not recognise .vue file definitions.

declare module '*.vue' {
    import Vue from 'vue';
   export default Vue;
 }

The problem has been explained in my blog post here: https://danpottsdoes.wordpress.com/2017/09/28/unit-testing-vue-class-components-using-typescript-chai-sinon-my-findings