Make sure the router is aware of the nextExport

Based on the we can change the routing to do SSR always.
Also make sure pageLoader don't download the page via
client side twice.

lib/link.js

@@ -1,3 +1,5 @@
+/* global __NEXT_DATA__ */
+
 import { resolve, format, parse } from 'url'
 import React, { Component, Children } from 'react'
 import PropTypes from 'prop-types'
@@ -38,6 +40,10 @@ export default class Link extends Component {
       return
     }
 
+    if (__NEXT_DATA__.nextExport) {
+      return
+    }
+
     let { href, as } = this
 
     if (!isLocal(href)) {
@@ -73,6 +79,7 @@ export default class Link extends Component {
   }
 
   prefetch () {
+    if (__NEXT_DATA__.nextExport) return
     if (!this.props.prefetch) return
     if (typeof window === 'undefined') return
 
@@ -122,6 +129,16 @@ export default class Link extends Component {
       props.href = as || href
     }
 
+    // Add the ending slash to the paths. So, we can serve the
+    // "<page>/index.html" directly.
+    const endsWithSlash = /\/$/.test(props.href)
+    if (
+      __NEXT_DATA__.nextExport &&
+      !endsWithSlash
+    ) {
+      props.href = `${props.href}/`
+    }
+
     return React.cloneElement(child, props)
   }
 }

lib/page-loader.js

@@ -47,6 +47,12 @@ export default class PageLoader {
 
       this.registerEvents.on(route, fire)
 
+      // If the page is loading via SSR, we need to wait for it
+      // rather downloading it again.
+      if (document.getElementById(`__NEXT_PAGE__${route}`)) {
+        return
+      }
+
       // Load the script if not asked to load yet.
       if (!this.loadingRoutes[route]) {
         this.loadScript(route)

lib/router/router.js

@@ -1,3 +1,4 @@
+/* global __NEXT_DATA__ */
 import { parse, format } from 'url'
 import mitt from 'mitt'
 import shallowEquals from '../shallow-equals'
@@ -120,6 +121,16 @@ export default class Router {
     const url = typeof _url === 'object' ? format(_url) : _url
     const as = typeof _as === 'object' ? format(_as) : _as
 
+    // We need to load the page via SSR everytime if we
+    // are in the nextExport mode.
+    if (__NEXT_DATA__.nextExport) {
+      // Add the ending slash to the paths. So, we can serve the
+      // "<page>/index.html" directly.
+      const endsWithSlash = /\/$/.test(as)
+      window.location.href = endsWithSlash ? as : `${as}/`
+      return
+    }
+
     this.abortComponentLoad(as)
     const { pathname, query } = parse(url, true)
 
@@ -267,6 +278,7 @@ export default class Router {
   }
 
   async prefetch (url) {
+    if (__NEXT_DATA__.nextExport) return
     // We don't add support for prefetch in the development mode.
     // If we do that, our on-demand-entries optimization won't performs better
     if (process.env.NODE_ENV === 'development') return

server/document.js

@@ -133,7 +133,7 @@ export class NextScript extends Component {
 
   render () {
     const { staticMarkup, __NEXT_DATA__ } = this.context._documentProps
-    const { realPathname, buildId, assetPrefix } = __NEXT_DATA__
+    const { pathname, realPathname, buildId, assetPrefix } = __NEXT_DATA__
 
     return <div>
       {staticMarkup ? null : <script dangerouslySetInnerHTML={{
@@ -147,8 +147,8 @@ export class NextScript extends Component {
           }
         `
       }} />}
-      <script async type='text/javascript' src={`${assetPrefix}/_next/${buildId}/page${realPathname}`} />
+      <script async id={`__NEXT_PAGE__${pathname}`} type='text/javascript' src={`${assetPrefix}/_next/${buildId}/page${realPathname}`} />
-      <script async type='text/javascript' src={`${assetPrefix}/_next/${buildId}/page/_error.js`} />
+      <script async id={`__NEXT_PAGE__/_error`} type='text/javascript' src={`${assetPrefix}/_next/${buildId}/page/_error.js`} />
       {staticMarkup ? null : this.getScripts()}
     </div>
   }

server/export.js

@@ -37,17 +37,6 @@ export default async function (dir) {
     join(outDir, '_next', buildId, 'page')
   )
 
-  // Start the rendering process
-  const renderOpts = {
-    dir,
-    buildStats,
-    buildId,
-    assetPrefix: config.assetPrefix.replace(/\/$/, ''),
-    dev: false,
-    staticMarkup: false,
-    hotReloader: null
-  }
-
   // Get the exportPathMap from the `next.config.js`
   if (typeof config.exportPathMap !== 'function') {
     printAndExit(
@@ -59,6 +48,23 @@ export default async function (dir) {
   const exportPathMap = await config.exportPathMap()
   const exportPaths = Object.keys(exportPathMap)
 
+  // Start the rendering process
+  const renderOpts = {
+    dir,
+    buildStats,
+    buildId,
+    nextExport: true,
+    assetPrefix: config.assetPrefix.replace(/\/$/, ''),
+    dev: false,
+    staticMarkup: false,
+    hotReloader: null
+  }
+
+  // We need this for server rendering the Link component.
+  global.__NEXT_DATA__ = {
+    nextExport: true
+  }
+
   for (const path of exportPaths) {
     const { page, query } = exportPathMap[path]
     const req = { url: path }

server/render.js

@@ -40,7 +40,8 @@ async function doRender (req, res, pathname, query, {
   assetPrefix,
   dir = process.cwd(),
   dev = false,
-  staticMarkup = false
+  staticMarkup = false,
+  nextExport = false
 } = {}) {
   page = page || pathname
 
@@ -106,6 +107,7 @@ async function doRender (req, res, pathname, query, {
       buildId,
       buildStats,
       assetPrefix,
+      nextExport,
       err: (err) ? serializeError(dev, err) : null
     },
     dev,