Vue + Typescript – Import errors with class based decorators

I’m trying to set up Vue 3 with TypeScript and class-based components. However, I keep getting on error on importing the Component decorator the Vue constructor:

This expression is not callable. Type 'typeof
import("/Users/*folder*/node_modules/vue-class-component/dist/vue-class-component")'
has no call signatures. Vetur(2349)

mycode.vue:

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

@Component // 1st Error '@Component'
export default class ProdItem extends Vue { // 2nd error 'Vue'
  
}
</script>

Answer

You might be trying to use the example from the official vue-class-component docs, but that’s currently for the 7x version, which can only be used with Vue 2.

Vue 3 requires vue-class-component 8x, which is not yet documented, but you can refer to vue-class-component Issue #406 that describes the changes. The notices relevant to your question:

• @Component will be renamed to @Options.
• @Options is optional if you don’t declare any options with it.
• Vue constructor is provided from vue-class-component package.

Since your component has no options, you could just omit the @Options decorator from your component:

// BEFORE:
import Component from 'vue-class-component'
@Component
class {}

// AFTER:
/* no options used, so no @Options decorator needed */
class {}

Also, Vue 3 no longer exports the Vue constructor, but vue-class-component does, so your component would have to extend that instead:

// BEFORE:
import Vue from 'vue'

// AFTER:
import { Vue } from 'vue-class-component'

For reference, you can use Vue CLI to generate a Vue 3 + TypeScript project to play with a working example that uses the latest vue-class-component as described above.