avoid unnecessary reloads

lib/app/app.js

@@ -3,13 +3,8 @@ import Router from 'vue-router'
 import Content from './Content'
 import NotFound from '~notFound'
 import metadataMixin from './metadataMixin'
-
-// .temp/siteData.js is a dynamically generated file that:
-// 1. registers all *.md pages and *.vue files found in _components as global
-//    async components;
-// 2. exports siteData
-// 3. exports routes
-import { routes, siteData } from './.temp/siteData'
+import { routes } from './.temp/routes'
+import { siteData } from './.temp/siteData'
 
 Vue.use(Router)
 

lib/prepare.js

@@ -8,36 +8,41 @@ const { inferTitle, extractHeaders } = require('./util')
 
 mkdirp(tempPath)
 
+const tempCache = new Map()
+function writeTemp (file, content) {
+  // cache write to avoid hitting the dist if it didn't change
+  const cached = tempCache.get(file)
+  if (cached !== content) {
+    fs.writeFileSync(path.join(tempPath, file), content)
+    tempCache.set(file, content)
+  }
+}
+
 module.exports = async function prepare (sourceDir) {
   // 1. load options
   const options = await resolveOptions(sourceDir)
 
-  // 2. generate dynamic component registration file
+  // 2. generate routes & user components registration code
+  const routesCode = await genRoutesFile(options)
   const componentCode = await genComponentRegistrationFile(options)
 
-  // 3. generate routes
-  const routesCode = await genRoutesFile(options)
+  writeTemp('routes.js', [
+    componentCode,
+    routesCode
+  ].join('\n\n'))
 
-  // 4. generate siteData
+  // 3. generate siteData
   const dataCode = `export const siteData = ${JSON.stringify(options.siteData, null, 2)}`
+  writeTemp('siteData.js', dataCode)
 
-  fs.writeFileSync(
-    path.join(tempPath, 'siteData.js'),
-    [
-      componentCode,
-      routesCode,
-      dataCode
-    ].join('\n\n')
-  )
-
-  // 5. generate basic polyfill if need to support older browsers
+  // 4. generate basic polyfill if need to support older browsers
   let polyfillCode = ``
   if (!options.siteConfig.evergreen) {
     polyfillCode =
 `import 'es6-promise/auto'
 if (!Object.assign) Object.assign = require('object-assign')`
   }
-  fs.writeFileSync(path.join(tempPath, 'polyfill.js'), polyfillCode)
+  writeTemp('polyfill.js', polyfillCode)
 
   return options
 }
@@ -63,7 +68,7 @@ async function resolveOptions (sourceDir) {
       ? path.resolve(siteConfig.dest)
       : path.resolve(sourceDir, '.vuepress/dist'),
     publicPath: siteConfig.base || '/',
-    pageFiles: await globby(['**/*.md', '!.vuepress'], { cwd: sourceDir }),
+    pageFiles: sort(await globby(['**/*.md', '!.vuepress'], { cwd: sourceDir })),
     pagesData: null,
     themePath: null,
     notFoundPath: null
@@ -186,7 +191,7 @@ async function resolveComponents (sourceDir) {
   if (!fs.existsSync(componentDir)) {
     return
   }
-  return await globby(['**/*.vue'], { cwd: componentDir })
+  return sort(await globby(['**/*.vue'], { cwd: componentDir }))
 }
 
 async function genRoutesFile ({ siteData: { pages }, sourceDir, pageFiles }) {
@@ -212,3 +217,11 @@ async function genRoutesFile ({ siteData: { pages }, sourceDir, pageFiles }) {
     `export const routes = [${pages.map(genRoute).join(',')}\n]`
   )
 }
+
+function sort (arr) {
+  return arr.sort((a, b) => {
+    if (a < b) return -1
+    if (a > b) return 1
+    return 0
+  })
+}