Move out requires from renderToHTML (#5915)

This brings us one step closer to outputting serverless functions as renderToHTML now renders the passed components, which allows us to bundle the renderToHTML function together with statically imported components in webpack.

packages/next-server/server/get-dynamic-import-bundles.ts

@@ -5,7 +5,7 @@ export type ManifestItem = {
   publicPath: string
 }
 
-type Manifest = {[moduleId: string]: ManifestItem[]}
+export type Manifest = {[moduleId: string]: ManifestItem[]}
 
 type DynamicImportBundles = Set<ManifestItem>
 

packages/next-server/server/get-page-files.ts

@@ -1,6 +1,7 @@
 import {normalizePagePath} from './require'
 
-type BuildManifest = {
+export type BuildManifest = {
+  devFiles: string[],
   pages: {
     [page: string]: string[]
   }

packages/next-server/server/load-components.ts

@@ -0,0 +1,21 @@
+import {join} from 'path'
+import {CLIENT_STATIC_FILES_PATH, BUILD_MANIFEST, REACT_LOADABLE_MANIFEST, SERVER_DIRECTORY} from 'next-server/constants'
+import {requirePage} from './require'
+
+function interopDefault (mod: any) {
+  return mod.default || mod
+}
+
+export async function loadComponents (distDir: string, buildId: string, pathname: string) {
+  const documentPath = join(distDir, SERVER_DIRECTORY, CLIENT_STATIC_FILES_PATH, buildId, 'pages', '_document')
+  const appPath = join(distDir, SERVER_DIRECTORY, CLIENT_STATIC_FILES_PATH, buildId, 'pages', '_app')
+  let [buildManifest, reactLoadableManifest, Component, Document, App] = await Promise.all([
+    require(join(distDir, BUILD_MANIFEST)),
+    require(join(distDir, REACT_LOADABLE_MANIFEST)),
+    interopDefault(requirePage(pathname, distDir)),
+    interopDefault(require(documentPath)),
+    interopDefault(require(appPath))
+  ])
+
+  return {buildManifest, reactLoadableManifest, Component, Document, App}
+}

packages/next-server/server/next-server.ts

@@ -10,9 +10,10 @@ import {serveStatic} from './serve-static'
 import Router, {route, Route} from './router'
 import { isInternalUrl, isBlockedPage } from './utils'
 import loadConfig from 'next-server/next-config'
-import {PHASE_PRODUCTION_SERVER, BUILD_ID_FILE, CLIENT_STATIC_FILES_PATH, CLIENT_STATIC_FILES_RUNTIME} from 'next-server/constants'
+import {PHASE_PRODUCTION_SERVER, BUILD_ID_FILE, CLIENT_STATIC_FILES_PATH, CLIENT_STATIC_FILES_RUNTIME, BUILD_MANIFEST, REACT_LOADABLE_MANIFEST, SERVER_DIRECTORY} from 'next-server/constants'
 import * as asset from '../lib/asset'
 import * as envConfig from '../lib/runtime-config'
+import {loadComponents} from './load-components'
 
 type NextConfig = any
 
@@ -79,6 +80,11 @@ export default class Server {
     return PHASE_PRODUCTION_SERVER
   }
 
+  private logError(...args: any): void {
+    if(this.quiet) return
+    console.error(...args)
+  }
+
   private handleRequest (req: IncomingMessage, res: ServerResponse, parsedUrl?: UrlWithParsedQuery): Promise<void> {
     // Parse url if parsedUrl not provided
     if (!parsedUrl || typeof parsedUrl !== 'object') {
@@ -94,7 +100,7 @@ export default class Server {
     res.statusCode = 200
     return this.run(req, res, parsedUrl)
       .catch((err) => {
-        if (!this.quiet) console.error(err)
+        this.logError(err)
         res.statusCode = 500
         res.end('Internal Server Error')
       })
@@ -224,17 +230,22 @@ export default class Server {
     return this.sendHTML(req, res, html)
   }
 
+  private async renderToHTMLWithComponents(req: IncomingMessage, res: ServerResponse, pathname: string, query: ParsedUrlQuery = {}, opts: any) {
+    const result = await loadComponents(this.distDir, this.buildId, pathname)
+    return renderToHTML(req, res, pathname, query, {...result, ...opts})
+  }
+
   public async renderToHTML (req: IncomingMessage, res: ServerResponse, pathname: string, query: ParsedUrlQuery = {}): Promise<string|null> {
     try {
       // To make sure the try/catch is executed
-      const html = await renderToHTML(req, res, pathname, query, this.renderOpts)
+      const html = await this.renderToHTMLWithComponents(req, res, pathname, query, this.renderOpts)
       return html
     } catch (err) {
       if (err.code === 'ENOENT') {
         res.statusCode = 404
         return this.renderErrorToHTML(null, req, res, pathname, query)
       } else {
-        if (!this.quiet) console.error(err)
+        this.logError(err)
         res.statusCode = 500
         return this.renderErrorToHTML(err, req, res, pathname, query)
       }
@@ -251,7 +262,7 @@ export default class Server {
   }
 
   public async renderErrorToHTML (err: Error|null, req: IncomingMessage, res: ServerResponse, _pathname: string, query: ParsedUrlQuery = {}) {
-    return renderToHTML(req, res, '/_error', query, {...this.renderOpts, err})
+    return this.renderToHTMLWithComponents(req, res, '/_error', query, {...this.renderOpts, err})
   }
 
   public async render404 (req: IncomingMessage, res: ServerResponse, parsedUrl?: UrlWithParsedQuery): Promise<void> {

packages/next-server/server/render.tsx

@@ -3,15 +3,14 @@ import { ParsedUrlQuery } from 'querystring'
 import { join } from 'path'
 import React from 'react'
 import { renderToString, renderToStaticMarkup } from 'react-dom/server'
-import {requirePage} from './require'
 import Router from '../lib/router/router'
 import { loadGetInitialProps, isResSent } from '../lib/utils'
 import Head, { defaultHead } from '../lib/head'
 import Loadable from '../lib/loadable'
 import LoadableCapture from '../lib/loadable-capture'
-import { BUILD_MANIFEST, REACT_LOADABLE_MANIFEST, SERVER_DIRECTORY, CLIENT_STATIC_FILES_PATH } from 'next-server/constants'
+import { SERVER_DIRECTORY } from 'next-server/constants'
-import {getDynamicImportBundles, ManifestItem} from './get-dynamic-import-bundles'
+import {getDynamicImportBundles, Manifest as ReactLoadableManifest, ManifestItem} from './get-dynamic-import-bundles'
-import {getPageFiles} from './get-page-files'
+import {getPageFiles, BuildManifest} from './get-page-files'
 
 type Enhancer = (Component: React.ComponentType) => React.ComponentType
 type ComponentsEnhancer = {enhanceApp?: Enhancer, enhanceComponent?: Enhancer}|Enhancer
@@ -34,10 +33,6 @@ function enhanceComponents(options: ComponentsEnhancer, App: React.ComponentType
   }
 }
 
-function interoptDefault(mod: any) {
-  return mod.default || mod
-}
-
 function render(renderElementToString: (element: React.ReactElement<any>) => string, element: React.ReactElement<any>): {html: string, head: any} {
   let html
   let head
@@ -59,7 +54,13 @@ type RenderOpts = {
   assetPrefix?: string,
   err?: Error|null,
   nextExport?: boolean,
-  dev?: boolean
+  dev?: boolean,
+  buildManifest: BuildManifest, 
+  reactLoadableManifest: ReactLoadableManifest,
+  Component: React.ComponentType,
+  Document: React.ComponentType,
+  App: React.ComponentType,
+  ErrorDebug?: React.ComponentType<{error: Error}>
 }
 
 function renderDocument(Document: React.ComponentType, {
@@ -114,20 +115,16 @@ function renderDocument(Document: React.ComponentType, {
 export async function renderToHTML (req: IncomingMessage, res: ServerResponse, pathname: string, query: ParsedUrlQuery, renderOpts: RenderOpts): Promise<string|null> {
   const {
     err,
-    buildId,
-    distDir,
     dev = false,
-    staticMarkup = false
+    staticMarkup = false,
+    App,
+    Document,
+    Component,
+    buildManifest,
+    reactLoadableManifest,
+    ErrorDebug
   } = renderOpts
-  const documentPath = join(distDir, SERVER_DIRECTORY, CLIENT_STATIC_FILES_PATH, buildId, 'pages', '_document')
+
-  const appPath = join(distDir, SERVER_DIRECTORY, CLIENT_STATIC_FILES_PATH, buildId, 'pages', '_app')
-  let [buildManifest, reactLoadableManifest, Component, Document, App] = await Promise.all([
-    require(join(distDir, BUILD_MANIFEST)),
-    require(join(distDir, REACT_LOADABLE_MANIFEST)),
-    interoptDefault(requirePage(pathname, distDir)),
-    interoptDefault(require(documentPath)),
-    interoptDefault(require(appPath))
-  ])
 
   await Loadable.preloadAll() // Make sure all dynamic imports are loaded
 
@@ -165,14 +162,14 @@ export async function renderToHTML (req: IncomingMessage, res: ServerResponse, p
 
   const reactLoadableModules: string[] = []
   const renderPage = (options: ComponentsEnhancer = {}): {html: string, head: any} => {
-    const {App: EnhancedApp, Component: EnhancedComponent} = enhanceComponents(options, App, Component)
     const renderElementToString = staticMarkup ? renderToStaticMarkup : renderToString
 
-    if(err && dev) {
+    if(err && ErrorDebug) {
-      const ErrorDebug = require(join(distDir, SERVER_DIRECTORY, 'error-debug')).default
       return render(renderElementToString, <ErrorDebug error={err} />)
     }
 
+    const {App: EnhancedApp, Component: EnhancedComponent} = enhanceComponents(options, App, Component)
+
     return render(renderElementToString,
       <LoadableCapture report={(moduleName) => reactLoadableModules.push(moduleName)}>
         <EnhancedApp

packages/next/export/index.js

@@ -136,6 +136,8 @@ export default async function (dir, options, configuration) {
             env: process.env
           })
           worker.send({
+            distDir,
+            buildId,
             exportPaths: chunk.paths,
             exportPathMap: chunk.pathMap,
             outDir,

packages/next/export/worker.js

@@ -7,10 +7,13 @@ const mkdirp = require('mkdirp-then')
 const { renderToHTML } = require('next-server/dist/server/render')
 const { writeFile } = require('fs')
 const Sema = require('async-sema')
+const {loadComponents} = require('next-server/dist/server/load-components')
 
 process.on(
   'message',
   async ({
+    distDir,
+    buildId,
     exportPaths,
     exportPathMap,
     outDir,
@@ -37,7 +40,8 @@ process.on(
         const htmlFilepath = join(outDir, htmlFilename)
 
         await mkdirp(baseDir)
-        const html = await renderToHTML(req, res, page, query, renderOpts)
+        const components = await loadComponents(distDir, buildId, page)
+        const html = await renderToHTML(req, res, page, query, {...components, ...renderOpts})
         await new Promise((resolve, reject) =>
           writeFile(
             htmlFilepath,

packages/next/server/next-dev-server.js

@@ -3,11 +3,13 @@ import { join } from 'path'
 import HotReloader from './hot-reloader'
 import {route} from 'next-server/dist/server/router'
 import {PHASE_DEVELOPMENT_SERVER} from 'next-server/constants'
+import ErrorDebug from './error-debug'
 
 export default class DevServer extends Server {
   constructor (options) {
     super(options)
     this.renderOpts.dev = true
+    this.renderOpts.ErrorDebug = ErrorDebug
     this.devReady = new Promise(resolve => {
       this.setDevReady = resolve
     })