fix: filtering duplicate data

Author: reco_luan

example/docs/views/other/guide.md

@@ -3,6 +3,7 @@ title: vuepress-theme-reco
 date: 2019-04-09
 categories:
   - other
+  - test
 keys:
   - '123' 
 ---

helpers/postData.js

@@ -2,11 +2,16 @@ import { compareDate } from '@theme/helpers/utils'
 
 // 过滤博客数据
 export function filterPosts (posts, isTimeline) {
-  posts = posts.filter(item => {
+  posts = posts.filter((item, index) => {
     const { title, frontmatter: { home, date, publish }} = item
-    return isTimeline === true
-      ? !(home == true || title == undefined || date === undefined || publish === false)
-      : !(home == true || title == undefined || publish === false)
+    // 过滤多个分类时产生的重复数据
+    if (posts.indexOf(item) !== index) {
+      return false
+    } else {
+      return isTimeline === true
+        ? !(home == true || title == undefined || date === undefined || publish === false)
+        : !(home == true || title == undefined || publish === false)
+    }
   })
   return posts
 }