From 432e6620a35b61ad58c82c1bfaff8f956030077b Mon Sep 17 00:00:00 2001
From: ULIVZ <472590061@qq.com>
Date: Tue, 30 Oct 2018 02:05:14 +0800
Subject: [PATCH] refactor: log error when theme cannot be resolved

---
 packages/@vuepress/core/lib/prepare/loadTheme.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/@vuepress/core/lib/prepare/loadTheme.js b/packages/@vuepress/core/lib/prepare/loadTheme.js
index c06820f18a..3b15c118b8 100644
--- a/packages/@vuepress/core/lib/prepare/loadTheme.js
+++ b/packages/@vuepress/core/lib/prepare/loadTheme.js
@@ -48,8 +48,11 @@ module.exports = async function loadTheme (ctx) {
     themePath = localThemePath
     logger.tip(`\nApply theme located at ${chalk.gray(themePath)}...`)
   } else if (isString(theme)) {
-    const { entry: modulePath, name, shortcut } = themeResolver.resolve(theme, sourceDir)
-
+    const resolved = themeResolver.resolve(theme, sourceDir)
+    const { entry: modulePath, name, shortcut } = resolved
+    if (modulePath === null) {
+      throw new Error(`Cannot resolve theme ${theme}.`)
+    }
     if (modulePath.endsWith('.js') || modulePath.endsWith('.vue')) {
       themePath = path.parse(modulePath).dir
     } else {