refactor: add types for client VuePress plugin

Author: ulivz

packages/@vuepress/core/lib/app/app.js

@@ -7,7 +7,7 @@ import { siteData } from '@internal/siteData'
 import appEnhancers from '@internal/app-enhancers'
 import globalUIComponents from '@internal/global-ui'
 import ClientComputedMixin from '@transform/ClientComputedMixin'
-import Store from './plugins/Store'
+import VuePress from './plugins/VuePress'
 
 // built-in components
 import LoadableContent from './components/Content.vue'
@@ -32,7 +32,7 @@ if (module.hot) {
 Vue.config.productionTip = false
 
 Vue.use(Router)
-Vue.use(Store, '$vuepress')
+Vue.use(VuePress)
 // mixin for exposing $site and $page
 Vue.mixin(dataMixin(ClientComputedMixin, siteData))
 // component for rendering markdown content and setting title etc.

packages/@vuepress/core/lib/app/plugins/Store.d.ts

@@ -0,0 +1,15 @@
+import Vue from 'Vue'
+
+export declare class Store {
+  store: Vue;
+
+  $get(key: string): any;
+
+  $set(key: string, value: any): void;
+
+  $emit: typeof Vue.prototype.$emit;
+
+  $on: typeof Vue.prototype.$on;
+}
+
+

packages/@vuepress/core/lib/app/plugins/Store.js

@@ -1,6 +1,6 @@
 import Vue from 'vue'
 
-class Store {
+export default class Store {
   constructor () {
     this.store = new Vue({
       data: {
@@ -25,11 +25,3 @@ class Store {
     this.store.$on(...args)
   }
 }
-
-export default {
-  install (Vue, options = '$store') {
-    const store = new Store()
-    Vue[options] = store
-    Vue.prototype[options] = store
-  }
-}

packages/@vuepress/core/lib/app/plugins/VuePress.d.ts

@@ -0,0 +1,11 @@
+import { Store } from './Store';
+
+declare class VuePress extends Store {
+
+}
+
+declare module "vue/types/vue" {
+  interface Vue {
+    $vuepress: Store;
+  }
+}

packages/@vuepress/core/lib/app/plugins/VuePress.js

@@ -0,0 +1,13 @@
+import Store from './Store'
+
+class VuePress extends Store {
+
+}
+
+export default {
+  install (Vue) {
+    const store = new VuePress()
+    Vue.$vuepress = store
+    Vue.prototype.$vuepress = store
+  }
+}