vuex: Vuex/Typescript mappers issue: property does not exist on type 'CombinedVueInstance'

Version

3.0.1

Reproduction link

https://github.com/mzymta/vuex-mappers-issue

Steps to reproduce

Add mapped methods using mapMutations, mapActions, create another component method that uses any of the mapped methods. Build fails with error:

Error: Property NAME_OF_MAPPED_METHOD does not exist on type ‘CombinedVueInstance<Vue, …>’

The below code works fine if there is no methodThatUsesActionOrMutation() method. With methodThatUsesActionOrMutation() method build fails with error:

TS2339: Property ‘pushStringArray’ does not exist on type ‘CombinedVueInstance<Vue, {}, { methodThatUsesActionOrMutation(): void; }, { newStr: any; getLongS…’.

import Vue from 'vue';
import {mapActions, mapGetters, mapMutations} from 'vuex'

export default Vue.extend({
  computed: {
    ...mapGetters({
      getStringsArray: 'getStringsArray'
    }),
    newStr: {
      get(): string {
        return this.$store.state.newStr;
      },
      set(value: string) {
        this.$store.commit('setNewStr', value);
      }
    }
  },
  methods: {
    ...mapMutations({
      pushStringArray: 'pushStringArray'
    }),
    ...mapActions({
      pushStringArrayAsync: 'pushStringArrayAsync'
    }),
    methodThatUsesActionOrMutation() {
      // HERE COMES THE ERROR
      this.pushStringArray();
      console.log('done');
    }
  }
}

What is expected?

mapped method pushStringArray() can be used in other component methods - build doesn’t fail

What is actually happening?

Build fails with error: TS2339: Property ‘pushStringArray’ does not exist on type ‘CombinedVueInstance<Vue, {}, { methodThatUsesActionOrMutation(): void; }, { newStr: any; }, Reado…’.