declare module 'vue' { import { CompatVue } from '@vue/runtime-dom' const Vue: CompatVue export default Vue export * from '@vue/runtime-dom' } // https://next.vuex.vuejs.org/guide/migrating-to-4-0-from-3-x.html#typescript-support import { ComponentCustomProperties } from 'vue' import { Store } from 'vuex' declare module '@vue/runtime-core' { // Declare your own store states. interface State { count: number } interface ComponentCustomProperties { $store: Store } }