vuex/dist/vuex.esm.browser.js

/**
 * vuex v4.0.0-alpha.1
 * (c) 2020 Evan You
 * @license MIT
 */
import { inject, watch, computed, reactive } from 'vue';

const storeKey = 'store';

function useStore (key = null) {
  return inject(key !== null ? key : storeKey)
}

function applyMixin (app, store, injectKey) {
  app.provide(injectKey || storeKey, store);

  // TODO: Refactor this to use `provide/inject`. It's currently
  // not possible because Vue 3 doesn't work with `$` prefixed
  // `provide/inject` at the moment.
  app.mixin({
    beforeCreate () {
      if (!this.parent) {
        this.$store = typeof store === 'function' ? store() : store;
      } else {
        this.$store = this.parent.$options.$store;
      }
    }
  });
}

const target = typeof window !== 'undefined'
  ? window
  : typeof global !== 'undefined'
    ? global
    : {};
const devtoolHook = target.__VUE_DEVTOOLS_GLOBAL_HOOK__;

function devtoolPlugin (store) {
  if (!devtoolHook) return

  store._devtoolHook = devtoolHook;

  devtoolHook.emit('vuex:init', store);

  devtoolHook.on('vuex:travel-to-state', targetState => {
    store.replaceState(targetState);
  });

  store.subscribe((mutation, state) => {
    devtoolHook.emit('vuex:mutation', mutation, state);
  });
}

/**
 * Get the first item that pass the test
 * by second argument function
 *
 * @param {Array} list
 * @param {Function} f
 * @return {*}
 */

/**
 * forEach for object
 */
function forEachValue (obj, fn) {
  Object.keys(obj).forEach(key => fn(obj[key], key));
}

function isObject (obj) {
  return obj !== null && typeof obj === 'object'
}

function isPromise (val) {
  return val && typeof val.then === 'function'
}

function assert (condition, msg) {
  if (!condition) throw new Error(`[vuex] ${msg}`)
}

function partial (fn, arg) {
  return function () {
    return fn(arg)
  }
}

// Base data struct for store's module, package with some attribute and method
class Module {
  constructor (rawModule, runtime) {
    this.runtime = runtime;
    // Store some children item
    this._children = Object.create(null);
    // Store the origin module object which passed by programmer
    this._rawModule = rawModule;
    const rawState = rawModule.state;

    // Store the origin module's state
    this.state = (typeof rawState === 'function' ? rawState() : rawState) || {};
  }

  get namespaced () {
    return !!this._rawModule.namespaced
  }

  addChild (key, module) {
    this._children[key] = module;
  }

  removeChild (key) {
    delete this._children[key];
  }

  getChild (key) {
    return this._children[key]
  }

  update (rawModule) {
    this._rawModule.namespaced = rawModule.namespaced;
    if (rawModule.actions) {
      this._rawModule.actions = rawModule.actions;
    }
    if (rawModule.mutations) {
      this._rawModule.mutations = rawModule.mutations;
    }
    if (rawModule.getters) {
      this._rawModule.getters = rawModule.getters;
    }
  }

  forEachChild (fn) {
    forEachValue(this._children, fn);
  }

  forEachGetter (fn) {
    if (this._rawModule.getters) {
      forEachValue(this._rawModule.getters, fn);
    }
  }

  forEachAction (fn) {
    if (this._rawModule.actions) {
      forEachValue(this._rawModule.actions, fn);
    }
  }

  forEachMutation (fn) {
    if (this._rawModule.mutations) {
      forEachValue(this._rawModule.mutations, fn);
    }
  }
}

class ModuleCollection {
  constructor (rawRootModule) {
    // register root module (Vuex.Store options)
    this.register([], rawRootModule, false);
  }

  get (path) {
    return path.reduce((module, key) => {
      return module.getChild(key)
    }, this.root)
  }

  getNamespace (path) {
    let module = this.root;
    return path.reduce((namespace, key) => {
      module = module.getChild(key);
      return namespace + (module.namespaced ? key + '/' : '')
    }, '')
  }

  update (rawRootModule) {
    update([], this.root, rawRootModule);
  }

  register (path, rawModule, runtime = true) {
    {
      assertRawModule(path, rawModule);
    }

    const newModule = new Module(rawModule, runtime);
    if (path.length === 0) {
      this.root = newModule;
    } else {
      const parent = this.get(path.slice(0, -1));
      parent.addChild(path[path.length - 1], newModule);
    }

    // register nested modules
    if (rawModule.modules) {
      forEachValue(rawModule.modules, (rawChildModule, key) => {
        this.register(path.concat(key), rawChildModule, runtime);
      });
    }
  }

  unregister (path) {
    const parent = this.get(path.slice(0, -1));
    const key = path[path.length - 1];
    if (!parent.getChild(key).runtime) return

    parent.removeChild(key);
  }
}

function update (path, targetModule, newModule) {
  {
    assertRawModule(path, newModule);
  }

  // update target module
  targetModule.update(newModule);

  // update nested modules
  if (newModule.modules) {
    for (const key in newModule.modules) {
      if (!targetModule.getChild(key)) {
        {
          console.warn(
            `[vuex] trying to add a new module '${key}' on hot reloading, ` +
            'manual reload is needed'
          );
        }
        return
      }
      update(
        path.concat(key),
        targetModule.getChild(key),
        newModule.modules[key]
      );
    }
  }
}

const functionAssert = {
  assert: value => typeof value === 'function',
  expected: 'function'
};

const objectAssert = {
  assert: value => typeof value === 'function' ||
    (typeof value === 'object' && typeof value.handler === 'function'),
  expected: 'function or object with "handler" function'
};

const assertTypes = {
  getters: functionAssert,
  mutations: functionAssert,
  actions: objectAssert
};

function assertRawModule (path, rawModule) {
  Object.keys(assertTypes).forEach(key => {
    if (!rawModule[key]) return

    const assertOptions = assertTypes[key];

    forEachValue(rawModule[key], (value, type) => {
      assert(
        assertOptions.assert(value),
        makeAssertionMessage(path, key, type, value, assertOptions.expected)
      );
    });
  });
}

function makeAssertionMessage (path, key, type, value, expected) {
  let buf = `${key} should be ${expected} but "${key}.${type}"`;
  if (path.length > 0) {
    buf += ` in module "${path.join('.')}"`;
  }
  buf += ` is ${JSON.stringify(value)}.`;
  return buf
}

// let Vue // bind on install

function createStore (options) {
  return new Store(options)
}

class Store {
  constructor (options = {}) {
    // TODO: Bring back this one if needed.
    //
    // Auto install if it is not done yet and `window` has `Vue`.
    // To allow users to avoid auto-installation in some cases,
    // this code should be placed here. See #731
    // if (!Vue && typeof window !== 'undefined' && window.Vue) {
    //   install(window.Vue)
    // }

    {
      // TODO: Maybe we can remove this depending on the new implementation.
      // assert(Vue, `must call Vue.use(Vuex) before creating a store instance.`)
      assert(typeof Promise !== 'undefined', `vuex requires a Promise polyfill in this browser.`);
      assert(this instanceof Store, `store must be called with the new operator.`);
    }

    const {
      plugins = [],
      strict = false
    } = options;

    // store internal state
    this._committing = false;
    this._actions = Object.create(null);
    this._actionSubscribers = [];
    this._mutations = Object.create(null);
    this._wrappedGetters = Object.create(null);
    this._modules = new ModuleCollection(options);
    this._modulesNamespaceMap = Object.create(null);
    this._subscribers = [];
    this._makeLocalGettersCache = Object.create(null);

    // bind commit and dispatch to self
    const store = this;
    const { dispatch, commit } = this;
    this.dispatch = function boundDispatch (type, payload) {
      return dispatch.call(store, type, payload)
    };
    this.commit = function boundCommit (type, payload, options) {
      return commit.call(store, type, payload, options)
    };

    // strict mode
    this.strict = strict;

    const state = this._modules.root.state;

    // init root module.
    // this also recursively registers all sub-modules
    // and collects all module getters inside this._wrappedGetters
    installModule(this, state, [], this._modules.root);

    // initialize the store vm, which is responsible for the reactivity
    // (also registers _wrappedGetters as computed properties)
    resetStoreVM(this, state);

    // apply plugins
    plugins.forEach(plugin => plugin(this));

    const useDevtools = options.devtools !== undefined ? options.devtools : /* Vue.config.devtools */ true;
    if (useDevtools) {
      devtoolPlugin(this);
    }
  }

  install (app, injectKey) {
    // TODO: Removing double install check for now. Maybe we can bring this
    // feature back again if needed.
    //
    // if (Vue && _Vue === Vue) {
    //   if ("development" !== 'production') {
    //     console.error(
    //       '[vuex] already installed. Vue.use(Vuex) should be called only once.'
    //     )
    //   }
    //   return
    // }
    // Vue = _Vue

    applyMixin(app, this, injectKey);
  }

  get state () {
    return this._vm._data.$$state
  }

  set state (v) {
    {
      assert(false, `use store.replaceState() to explicit replace store state.`);
    }
  }

  commit (_type, _payload, _options) {
    // check object-style commit
    const {
      type,
      payload,
      options
    } = unifyObjectStyle(_type, _payload, _options);

    const mutation = { type, payload };
    const entry = this._mutations[type];
    if (!entry) {
      {
        console.error(`[vuex] unknown mutation type: ${type}`);
      }
      return
    }
    this._withCommit(() => {
      entry.forEach(function commitIterator (handler) {
        handler(payload);
      });
    });

    this._subscribers
      .slice() // shallow copy to prevent iterator invalidation if subscriber synchronously calls unsubscribe
      .forEach(sub => sub(mutation, this.state));

    if (
      options && options.silent
    ) {
      console.warn(
        `[vuex] mutation type: ${type}. Silent option has been removed. ` +
        'Use the filter functionality in the vue-devtools'
      );
    }
  }

  dispatch (_type, _payload) {
    // check object-style dispatch
    const {
      type,
      payload
    } = unifyObjectStyle(_type, _payload);

    const action = { type, payload };
    const entry = this._actions[type];
    if (!entry) {
      {
        console.error(`[vuex] unknown action type: ${type}`);
      }
      return
    }

    try {
      this._actionSubscribers
        .slice() // shallow copy to prevent iterator invalidation if subscriber synchronously calls unsubscribe
        .filter(sub => sub.before)
        .forEach(sub => sub.before(action, this.state));
    } catch (e) {
      {
        console.warn(`[vuex] error in before action subscribers: `);
        console.error(e);
      }
    }

    const result = entry.length > 1
      ? Promise.all(entry.map(handler => handler(payload)))
      : entry[0](payload);

    return result.then(res => {
      try {
        this._actionSubscribers
          .filter(sub => sub.after)
          .forEach(sub => sub.after(action, this.state));
      } catch (e) {
        {
          console.warn(`[vuex] error in after action subscribers: `);
          console.error(e);
        }
      }
      return res
    })
  }

  subscribe (fn) {
    return genericSubscribe(fn, this._subscribers)
  }

  subscribeAction (fn) {
    const subs = typeof fn === 'function' ? { before: fn } : fn;
    return genericSubscribe(subs, this._actionSubscribers)
  }

  watch (getter, cb, options) {
    {
      assert(typeof getter === 'function', `store.watch only accepts a function.`);
    }
    return watch(() => getter(this.state, this.getters), cb, Object.assign({}, options))
  }

  replaceState (state) {
    this._withCommit(() => {
      this._vm._data.$$state = state;
    });
  }

  registerModule (path, rawModule, options = {}) {
    if (typeof path === 'string') path = [path];

    {
      assert(Array.isArray(path), `module path must be a string or an Array.`);
      assert(path.length > 0, 'cannot register the root module by using registerModule.');
    }

    this._modules.register(path, rawModule);
    installModule(this, this.state, path, this._modules.get(path), options.preserveState);
    // reset store to update getters...
    resetStoreVM(this, this.state);
  }

  unregisterModule (path) {
    if (typeof path === 'string') path = [path];

    {
      assert(Array.isArray(path), `module path must be a string or an Array.`);
    }

    this._modules.unregister(path);
    this._withCommit(() => {
      const parentState = getNestedState(this.state, path.slice(0, -1));
      delete parentState[path[path.length - 1]];
    });
    resetStore(this);
  }

  hotUpdate (newOptions) {
    this._modules.update(newOptions);
    resetStore(this, true);
  }

  _withCommit (fn) {
    const committing = this._committing;
    this._committing = true;
    fn();
    this._committing = committing;
  }
}

function genericSubscribe (fn, subs) {
  if (subs.indexOf(fn) < 0) {
    subs.push(fn);
  }
  return () => {
    const i = subs.indexOf(fn);
    if (i > -1) {
      subs.splice(i, 1);
    }
  }
}

function resetStore (store, hot) {
  store._actions = Object.create(null);
  store._mutations = Object.create(null);
  store._wrappedGetters = Object.create(null);
  store._modulesNamespaceMap = Object.create(null);
  const state = store.state;
  // init all modules
  installModule(store, state, [], store._modules.root, true);
  // reset vm
  resetStoreVM(store, state, hot);
}

function resetStoreVM (store, state, hot) {
  const oldVm = store._vm;

  // bind store public getters
  store.getters = {};
  // reset local getters cache
  store._makeLocalGettersCache = Object.create(null);
  const wrappedGetters = store._wrappedGetters;
  const computedObj = {};
  forEachValue(wrappedGetters, (fn, key) => {
    // TODO: Refactor following code and comment. We can simplify many things
    // using computed function.
    //
    // use computed to leverage its lazy-caching mechanism
    // direct inline function use will lead to closure preserving oldVm.
    // using partial to return function with only arguments preserved in closure environment.
    computedObj[key] = partial(fn, store);
    Object.defineProperty(store.getters, key, {
      get: () => computed(() => computedObj[key]()).value,
      enumerable: true // for local getters
    });
  });

  // TODO: Bring back this if it's still needed.
  //
  // use a Vue instance to store the state tree
  // suppress warnings just in case the user has added
  // some funky global mixins
  // const silent = Vue.config.silent
  // Vue.config.silent = true

  // TODO: Refactor the code and remove this comment.
  //
  // New impl with reactive. Defining redundunt keys to make it as close as
  // the old impl api.
  store._vm = reactive({
    _data: {
      $$state: state
    }
  });

  // TODO: Bring back maybe?
  //
  // Vue.config.silent = silent

  // enable strict mode for new vm
  if (store.strict) {
    enableStrictMode(store);
  }

  if (oldVm) {
    if (hot) {
      // dispatch changes in all subscribed watchers
      // to force getter re-evaluation for hot reloading.
      store._withCommit(() => {
        oldVm._data.$$state = null;
      });
    }
    // TODO: I think we don't need this anymore since we're not using vm?
    // Vue.nextTick(() => oldVm.$destroy())
  }
}

function installModule (store, rootState, path, module, hot) {
  const isRoot = !path.length;
  const namespace = store._modules.getNamespace(path);

  // register in namespace map
  if (module.namespaced) {
    if (store._modulesNamespaceMap[namespace] && "development" !== 'production') {
      console.error(`[vuex] duplicate namespace ${namespace} for the namespaced module ${path.join('/')}`);
    }
    store._modulesNamespaceMap[namespace] = module;
  }

  // set state
  if (!isRoot && !hot) {
    const parentState = getNestedState(rootState, path.slice(0, -1));
    const moduleName = path[path.length - 1];
    store._withCommit(() => {
      {
        if (moduleName in parentState) {
          console.warn(
            `[vuex] state field "${moduleName}" was overridden by a module with the same name at "${path.join('.')}"`
          );
        }
      }
      parentState[moduleName] = module.state;
    });
  }

  const local = module.context = makeLocalContext(store, namespace, path);

  module.forEachMutation((mutation, key) => {
    const namespacedType = namespace + key;
    registerMutation(store, namespacedType, mutation, local);
  });

  module.forEachAction((action, key) => {
    const type = action.root ? key : namespace + key;
    const handler = action.handler || action;
    registerAction(store, type, handler, local);
  });

  module.forEachGetter((getter, key) => {
    const namespacedType = namespace + key;
    registerGetter(store, namespacedType, getter, local);
  });

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

/**
 * make localized dispatch, commit, getters and state
 * if there is no namespace, just use root ones
 */
function makeLocalContext (store, namespace, path) {
  const noNamespace = namespace === '';

  const local = {
    dispatch: noNamespace ? store.dispatch : (_type, _payload, _options) => {
      const args = unifyObjectStyle(_type, _payload, _options);
      const { payload, options } = args;
      let { type } = args;

      if (!options || !options.root) {
        type = namespace + type;
        if (!store._actions[type]) {
          console.error(`[vuex] unknown local action type: ${args.type}, global type: ${type}`);
          return
        }
      }

      return store.dispatch(type, payload)
    },

    commit: noNamespace ? store.commit : (_type, _payload, _options) => {
      const args = unifyObjectStyle(_type, _payload, _options);
      const { payload, options } = args;
      let { type } = args;

      if (!options || !options.root) {
        type = namespace + type;
        if (!store._mutations[type]) {
          console.error(`[vuex] unknown local mutation type: ${args.type}, global type: ${type}`);
          return
        }
      }

      store.commit(type, payload, options);
    }
  };

  // getters and state object must be gotten lazily
  // because they will be changed by vm update
  Object.defineProperties(local, {
    getters: {
      get: noNamespace
        ? () => store.getters
        : () => makeLocalGetters(store, namespace)
    },
    state: {
      get: () => getNestedState(store.state, path)
    }
  });

  return local
}

function makeLocalGetters (store, namespace) {
  if (!store._makeLocalGettersCache[namespace]) {
    const gettersProxy = {};
    const splitPos = namespace.length;
    Object.keys(store.getters).forEach(type => {
      // skip if the target getter is not match this namespace
      if (type.slice(0, splitPos) !== namespace) return

      // extract local getter type
      const localType = type.slice(splitPos);

      // Add a port to the getters proxy.
      // Define as getter property because
      // we do not want to evaluate the getters in this time.
      Object.defineProperty(gettersProxy, localType, {
        get: () => store.getters[type],
        enumerable: true
      });
    });
    store._makeLocalGettersCache[namespace] = gettersProxy;
  }

  return store._makeLocalGettersCache[namespace]
}

function registerMutation (store, type, handler, local) {
  const entry = store._mutations[type] || (store._mutations[type] = []);
  entry.push(function wrappedMutationHandler (payload) {
    handler.call(store, local.state, payload);
  });
}

function registerAction (store, type, handler, local) {
  const entry = store._actions[type] || (store._actions[type] = []);
  entry.push(function wrappedActionHandler (payload) {
    let res = handler.call(store, {
      dispatch: local.dispatch,
      commit: local.commit,
      getters: local.getters,
      state: local.state,
      rootGetters: store.getters,
      rootState: store.state
    }, payload);
    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
    }
  });
}

function registerGetter (store, type, rawGetter, local) {
  if (store._wrappedGetters[type]) {
    {
      console.error(`[vuex] duplicate getter key: ${type}`);
    }
    return
  }
  store._wrappedGetters[type] = function wrappedGetter (store) {
    return rawGetter(
      local.state, // local state
      local.getters, // local getters
      store.state, // root state
      store.getters // root getters
    )
  };
}

function enableStrictMode (store) {
  watch(() => store._vm._data.$$state, () => {
    {
      assert(store._committing, `do not mutate vuex store state outside mutation handlers.`);
    }
  }, { deep: true, flush: 'sync' });
}

function getNestedState (state, path) {
  return path.reduce((state, key) => state[key], state)
}

function unifyObjectStyle (type, payload, options) {
  if (isObject(type) && type.type) {
    options = payload;
    payload = type;
    type = type.type;
  }

  {
    assert(typeof type === 'string', `expects string as the type, but found ${typeof type}.`);
  }

  return { type, payload, options }
}

/**
 * Reduce the code which written in Vue.js for getting the state.
 * @param {String} [namespace] - Module's namespace
 * @param {Object|Array} states # Object's item can be a function which accept state and getters for param, you can do something for state and getters in it.
 * @param {Object}
 */
const mapState = normalizeNamespace((namespace, states) => {
  const res = {};
  if (!isValidMap(states)) {
    console.error('[vuex] mapState: mapper parameter must be either an Array or an Object');
  }
  normalizeMap(states).forEach(({ key, val }) => {
    res[key] = function mappedState () {
      let state = this.$store.state;
      let getters = this.$store.getters;
      if (namespace) {
        const module = getModuleByNamespace(this.$store, 'mapState', namespace);
        if (!module) {
          return
        }
        state = module.context.state;
        getters = module.context.getters;
      }
      return typeof val === 'function'
        ? val.call(this, state, getters)
        : state[val]
    };
    // mark vuex getter for devtools
    res[key].vuex = true;
  });
  return res
});

/**
 * Reduce the code which written in Vue.js for committing the mutation
 * @param {String} [namespace] - Module's namespace
 * @param {Object|Array} mutations # Object's item can be a function which accept `commit` function as the first param, it can accept anthor params. You can commit mutation and do any other things in this function. specially, You need to pass anthor params from the mapped function.
 * @return {Object}
 */
const mapMutations = normalizeNamespace((namespace, mutations) => {
  const res = {};
  if (!isValidMap(mutations)) {
    console.error('[vuex] mapMutations: mapper parameter must be either an Array or an Object');
  }
  normalizeMap(mutations).forEach(({ key, val }) => {
    res[key] = function mappedMutation (...args) {
      // Get the commit method from store
      let commit = this.$store.commit;
      if (namespace) {
        const module = getModuleByNamespace(this.$store, 'mapMutations', namespace);
        if (!module) {
          return
        }
        commit = module.context.commit;
      }
      return typeof val === 'function'
        ? val.apply(this, [commit].concat(args))
        : commit.apply(this.$store, [val].concat(args))
    };
  });
  return res
});

/**
 * Reduce the code which written in Vue.js for getting the getters
 * @param {String} [namespace] - Module's namespace
 * @param {Object|Array} getters
 * @return {Object}
 */
const mapGetters = normalizeNamespace((namespace, getters) => {
  const res = {};
  if (!isValidMap(getters)) {
    console.error('[vuex] mapGetters: mapper parameter must be either an Array or an Object');
  }
  normalizeMap(getters).forEach(({ key, val }) => {
    // The namespace has been mutated by normalizeNamespace
    val = namespace + val;
    res[key] = function mappedGetter () {
      if (namespace && !getModuleByNamespace(this.$store, 'mapGetters', namespace)) {
        return
      }
      if (!(val in this.$store.getters)) {
        console.error(`[vuex] unknown getter: ${val}`);
        return
      }
      return this.$store.getters[val]
    };
    // mark vuex getter for devtools
    res[key].vuex = true;
  });
  return res
});

/**
 * Reduce the code which written in Vue.js for dispatch the action
 * @param {String} [namespace] - Module's namespace
 * @param {Object|Array} actions # Object's item can be a function which accept `dispatch` function as the first param, it can accept anthor params. You can dispatch action and do any other things in this function. specially, You need to pass anthor params from the mapped function.
 * @return {Object}
 */
const mapActions = normalizeNamespace((namespace, actions) => {
  const res = {};
  if (!isValidMap(actions)) {
    console.error('[vuex] mapActions: mapper parameter must be either an Array or an Object');
  }
  normalizeMap(actions).forEach(({ key, val }) => {
    res[key] = function mappedAction (...args) {
      // get dispatch function from store
      let dispatch = this.$store.dispatch;
      if (namespace) {
        const module = getModuleByNamespace(this.$store, 'mapActions', namespace);
        if (!module) {
          return
        }
        dispatch = module.context.dispatch;
      }
      return typeof val === 'function'
        ? val.apply(this, [dispatch].concat(args))
        : dispatch.apply(this.$store, [val].concat(args))
    };
  });
  return res
});

/**
 * Rebinding namespace param for mapXXX function in special scoped, and return them by simple object
 * @param {String} namespace
 * @return {Object}
 */
const createNamespacedHelpers = (namespace) => ({
  mapState: mapState.bind(null, namespace),
  mapGetters: mapGetters.bind(null, namespace),
  mapMutations: mapMutations.bind(null, namespace),
  mapActions: mapActions.bind(null, namespace)
});

/**
 * Normalize the map
 * normalizeMap([1, 2, 3]) => [ { key: 1, val: 1 }, { key: 2, val: 2 }, { key: 3, val: 3 } ]
 * normalizeMap({a: 1, b: 2, c: 3}) => [ { key: 'a', val: 1 }, { key: 'b', val: 2 }, { key: 'c', val: 3 } ]
 * @param {Array|Object} map
 * @return {Object}
 */
function normalizeMap (map) {
  if (!isValidMap(map)) {
    return []
  }
  return Array.isArray(map)
    ? map.map(key => ({ key, val: key }))
    : Object.keys(map).map(key => ({ key, val: map[key] }))
}

/**
 * Validate whether given map is valid or not
 * @param {*} map
 * @return {Boolean}
 */
function isValidMap (map) {
  return Array.isArray(map) || isObject(map)
}

/**
 * Return a function expect two param contains namespace and map. it will normalize the namespace and then the param's function will handle the new namespace and the map.
 * @param {Function} fn
 * @return {Function}
 */
function normalizeNamespace (fn) {
  return (namespace, map) => {
    if (typeof namespace !== 'string') {
      map = namespace;
      namespace = '';
    } else if (namespace.charAt(namespace.length - 1) !== '/') {
      namespace += '/';
    }
    return fn(namespace, map)
  }
}

/**
 * Search a special module from store by namespace. if module not exist, print error message.
 * @param {Object} store
 * @param {String} helper
 * @param {String} namespace
 * @return {Object}
 */
function getModuleByNamespace (store, helper, namespace) {
  const module = store._modulesNamespaceMap[namespace];
  if (!module) {
    console.error(`[vuex] module namespace not found in ${helper}(): ${namespace}`);
  }
  return module
}

var index_esm = {
  version: '4.0.0-alpha.1',
  createStore,
  Store,
  useStore,
  mapState,
  mapMutations,
  mapGetters,
  mapActions,
  createNamespacedHelpers
};

export default index_esm;
export { createStore, Store, useStore, mapState, mapMutations, mapGetters, mapActions, createNamespacedHelpers };