fix #1077: async function support for additionalPages plugin

packages/@vuepress/core/lib/plugin-api/override/AdditionalPagesOption.js

@@ -0,0 +1,19 @@
+'use strict'
+
+const AsyncOption = require('../abstract/AsyncOption')
+
+/**
+ * additionalPages option.
+ */
+
+module.exports = class AdditionalPagesOption extends AsyncOption {
+  async apply (ctx) {
+    await super.asyncApply()
+
+    await Promise.all(
+      this.appliedValues.map(async (options) => {
+        await ctx.addPage(options)
+      })
+    )
+  }
+}

packages/@vuepress/core/lib/plugin-api/override/instantiateOption.js

@@ -3,6 +3,7 @@ const ClientDynamicModulesOption = require('./ClientDynamicModulesOption')
 const GlobalUIComponentsOption = require('./GlobalUIComponentsOption')
 const DefineOption = require('./DefineOption')
 const AliasOption = require('./AliasOption')
+const AdditionalPagesOption = require('./AdditionalPagesOption')
 const Option = require('../abstract/Option')
 const { PLUGIN_OPTION_MAP } = require('../constants')
 
@@ -23,6 +24,9 @@ module.exports = function instantiateOption (name) {
   case PLUGIN_OPTION_MAP.ALIAS.name:
     return new AliasOption(name)
 
+  case PLUGIN_OPTION_MAP.ADDITIONAL_PAGES.name:
+    return new AdditionalPagesOption(name)
+
   default: return new Option(name)
   }
 }

packages/@vuepress/core/lib/prepare/AppContext.js

@@ -103,11 +103,7 @@ module.exports = class AppContext {
     this.markdown = createMarkdown(this)
 
     await this.resolvePages()
-    await Promise.all(
-      this.pluginAPI.options.additionalPages.values.map(async (options) => {
-        await this.addPage(options)
-      })
-    )
+    await this.pluginAPI.options.additionalPages.apply(this)
 
     await this.pluginAPI.options.ready.apply()
     await Promise.all([

packages/docs/docs/plugin/option-api.md

@@ -354,7 +354,7 @@ export default {
 
 ## additionalPages
 
-- Type: `Array|Function`
+- Type: `Array|AsyncFunction`
 - Default: `undefined`
 
 Add a page pointing to a markdown file: