Update pages-loader to return one value (#8629)

* Update pages-loader to return one value

* de-dupe page mod update also

packages/next/build/webpack/loaders/next-client-pages-loader.ts

@@ -13,15 +13,15 @@ const nextClientPagesLoader: loader.Loader = function() {
 
   return `
     (window.__NEXT_P=window.__NEXT_P||[]).push([${stringifiedPage}, function() {
-      var page = require(${stringifiedAbsolutePagePath})
+      var mod = require(${stringifiedAbsolutePagePath})
       if(module.hot) {
         module.hot.accept(${stringifiedAbsolutePagePath}, function() {
           if(!next.router.components[${stringifiedPage}]) return
           var updatedPage = require(${stringifiedAbsolutePagePath})
-          next.router.update(${stringifiedPage}, updatedPage.default || updatedPage)
+          next.router.update(${stringifiedPage}, updatedPage)
         })
       }
-      return { page: page.default || page }
+      return mod
     }]);
   `
 }

packages/next/client/page-loader.js

@@ -141,9 +141,10 @@ export default class PageLoader {
   registerPage (route, regFn) {
     const register = () => {
       try {
-        const { error, page } = regFn()
-        this.pageCache[route] = { error, page }
-        this.pageRegisterEvents.emit(route, { error, page })
+        const mod = regFn()
+        const pageData = { page: mod.default || mod, mod }
+        this.pageCache[route] = pageData
+        this.pageRegisterEvents.emit(route, pageData)
       } catch (error) {
         this.pageCache[route] = { error }
         this.pageRegisterEvents.emit(route, { error })

packages/next/next-server/lib/router/router.ts

@@ -195,7 +195,8 @@ export default class Router implements BaseRouter {
     this.replace(url, as, options)
   }
 
-  update(route: string, Component: ComponentType) {
+  update(route: string, mod: any) {
+    const Component: ComponentType = mod.default || mod
     const data = this.components[route]
     if (!data) {
       throw new Error(`Cannot update unavailable route: ${route}`)