Vuex Store plugin to inject axios instance into actions for axios nuxt module: https://github.com/nuxt-community/modules/tree/master/modules/axios

axios-store-plugin.js

import Vuex from 'vuex';

// Copied from vuex/src/utils
function isPromise (val) {
  return val && typeof val.then === 'function'
}

// Based on registerAction  from vuex/src/store.js
function patchAction (store, type, handler, local) {
  const entry = store._actions[type] || (store._actions[type] = [])

  // TODO: should we check if last item contains a wrappedActionHandler ?
  if (entry.length > 0) entry.pop()

  entry.push(function wrappedActionHandler (payload, cb) {
    let res = handler({
      dispatch: local.dispatch,
      commit: local.commit,
      getters: local.getters,
      state: local.state,
      rootGetters: store.getters,
      rootState: store.state,
      $axios: store.$axios
    }, payload, cb)
    if (!isPromise(res)) {
      res = Promise.resolve(res)
    }
    if (store._devtoolHook) {
      return res.catch(err => {
        store._devtoolHook.emit('vuex:error', err)
        throw err
      })
    } else {
      return res
    }
  })
}

// Based on installModule from vuex/src/store.js
function patchModule (store, path, module, hot) {
  const namespace = store._modules.getNamespace(path)

  const local = module.context

  module.forEachAction((action, key) => {
    const namespacedType = namespace + key
    patchAction(store, namespacedType, action, local)
  })

  module.forEachChild((child, key) => {
    patchModule(store, path.concat(key), child, hot)
  })

}

export default function axiosStorePlugin() {
  return store => {
    // Patch all current modules to include $axios parameter in action handlers.
    patchModule(store, [], store._modules.root)

    // Patch registerModule to auto patch newly added dynamic modules
    const orig = Vuex.Store.prototype.registerModule;
    Vuex.Store.prototype.registerModule = function registerModule(path, rawModule) {
      orig.call(this, path, rawModule);
      patchModule(this, path, this._modules.get(path))
    };
  }
}

usage.js

import axiosStorePlugin from '~/axios/store-plugin';

export const state = () => ({
})

export const actions = {
  testAxios (ctx) {
    let $axios = ctx.$axios
  },

}
export const plugins = [
  axiosStorePlugin()
]