In order to mock a Vuex store with Jest, you essentially have to build a whole Vuex store that replicates what your existing Vuex store does. Below are how you mock each of the different types of functions in a Vuex store.

Actions

import Vuex from "vuex";
import { shallowMount, createLocalVue } from '@vue/test-utils'

const actions = {
	myAction: jest.fn()
};

const store = new Vuex.Store({
	actions
});

const localVue = createLocalVue();
localVue.use(Vuex);

const wrapper = shallowMount(MyComponenet, { store, localVue });

Getters

import Vuex from "vuex";
import { shallowMount, createLocalVue } from '@vue/test-utils'

const getters = {
	myData: () => [2, 4, 5, 6]
};

const store = new Vuex.Store({
	getters
});

const localVue = createLocalVue();
localVue.use(Vuex);

const wrapper = shallowMount(MyComponent, { store, localVue });