fix($plugin-pagination): better function transfer (close: #1338)

packages/@vuepress/plugin-pagination/enhanceAppFile.js

@@ -1,15 +1,9 @@
-import paginationMeta from '@dynamic/pagination'
+import * as paginationMeta from '@dynamic/pagination'
 
 class Pagination {
   constructor (pagination, { pages, route }) {
-    let { postsFilter, postsSorter } = pagination
-
-    /* eslint-disable no-eval */
-    postsFilter = eval(postsFilter)
-    postsSorter = eval(postsSorter)
-
+    const { postsFilter, postsSorter, paginationPages } = pagination
     const { path } = route
-    const { paginationPages } = pagination
 
     paginationPages.forEach((page, index) => {
       if (page.path === path) {

packages/@vuepress/plugin-pagination/index.js

@@ -16,16 +16,16 @@ module.exports = (options, ctx) => ({
   ],
 
   ready () {
-    let { postsFilter, postsSorter } = options
-    postsFilter = postsFilter || (({ type }) => type === 'post')
-    postsSorter = postsSorter || ((prev, next) => {
+    const { postsFilter, postsSorter } = options
+    ctx.postsFilter = postsFilter || (({ type }) => type === 'post')
+    ctx.postsSorter = postsSorter || ((prev, next) => {
       const prevTime = new Date(prev.frontmatter.date).getTime()
       const nextTime = new Date(next.frontmatter.date).getTime()
       return prevTime - nextTime > 0 ? -1 : 1
     })
 
     const { pages } = ctx
-    const posts = pages.filter(postsFilter)
+    const posts = pages.filter(ctx.postsFilter)
     const {
       perPagePosts = 10,
       paginationDir = 'page',
@@ -34,19 +34,14 @@ module.exports = (options, ctx) => ({
     } = options
 
     const intervallers = getIntervallers(posts.length, perPagePosts)
-    const pagination = {
-      paginationPages: intervallers.map((interval, index) => {
-        const path = index === 0
-          ? firstPagePath
-          : `/${paginationDir}/${index + 1}/`
-        return { path, interval }
-      }),
-      postsFilter: postsFilter.toString(),
-      postsSorter: postsSorter.toString()
-    }
+    ctx.paginationPages = intervallers.map((interval, index) => {
+      const path = index === 0
+        ? firstPagePath
+        : `/${paginationDir}/${index + 1}/`
+      return { path, interval }
+    })
 
-    ctx.pagination = pagination
-    pagination.paginationPages.forEach(({ path }, index) => {
+    ctx.paginationPages.forEach(({ path }, index) => {
       if (path === '/') {
         return
       }
@@ -63,7 +58,25 @@ module.exports = (options, ctx) => ({
   async clientDynamicModules () {
     return {
       name: 'pagination.js',
-      content: `export default ${JSON.stringify(ctx.pagination, null, 2)}`
+      content: `\
+export const paginationPages = ${JSON.stringify(ctx.paginationPages, null, 2)}
+export const postsFilter = ${stringifyFunction(ctx.postsFilter)}
+export const postsSorter = ${stringifyFunction(ctx.postsSorter)}`
     }
   }
 })
+
+function stringifyFunction (input) {
+  let output = String(input)
+  if (!/^(function\b|\()/.test(output)) {
+    /**
+     * fix edge case:
+     * ```js
+     * const foo = { bar () {} }
+     * stringifyFunction(foo.bar)
+     * ```
+     */
+    output = output.replace(/^[^(]+/, 'function')
+  }
+  return output
+}