Add RenderResult class (#28776)

vercel · Sep 4, 2021 · 7f83e6d · 7f83e6d
1 parent 85366a0
commit 7f83e6d
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Showing 8 changed files with 150 additions and 122 deletions.
diff --git a/packages/next/build/webpack/loaders/next-serverless-loader/page-handler.ts b/packages/next/build/webpack/loaders/next-serverless-loader/page-handler.ts
@@ -1,7 +1,7 @@
 import { IncomingMessage, ServerResponse } from 'http'
 import { parse as parseUrl, format as formatUrl, UrlWithParsedQuery } from 'url'
 import { DecodeError, isResSent } from '../../../../shared/lib/utils'
-import { sendPayload } from '../../../../server/send-payload'
+import { sendRenderResult } from '../../../../server/send-payload'
 import { getUtils, vercelHeader, ServerlessHandlerCtx } from './utils'
 
 import { renderToHTML } from '../../../../server/render'
@@ -11,7 +11,7 @@ import { setLazyProp, getCookieParser } from '../../../../server/api-utils'
 import { getRedirectStatus } from '../../../../lib/load-custom-routes'
 import getRouteNoAssetPath from '../../../../shared/lib/router/utils/get-route-from-asset-path'
 import { PERMANENT_REDIRECT_STATUS } from '../../../../shared/lib/constants'
-import { resultsToString } from '../../../../server/utils'
+import RenderResult from '../../../../server/render-result'
 
 export function getPageHandler(ctx: ServerlessHandlerCtx) {
   const {
@@ -335,22 +335,19 @@ export function getPageHandler(ctx: ServerlessHandlerCtx) {
                 defaultLocale: i18n?.defaultLocale,
               })
             )
-            const html = result2 ? await resultsToString([result2]) : ''
-            sendPayload(
+            sendRenderResult({
               req,
               res,
-              html,
-              'html',
-              {
-                generateEtags,
-                poweredByHeader,
-              },
-              {
+              result: result2 ?? RenderResult.empty,
+              type: 'html',
+              generateEtags,
+              poweredByHeader,
+              options: {
                 private: isPreviewMode || page === '/404',
                 stateful: !!getServerSideProps,
                 revalidate: renderOpts.revalidate,
-              }
-            )
+              },
+            })
             return null
           } else if (renderOpts.isRedirect && !_nextData) {
             const redirect = {
@@ -377,21 +374,21 @@ export function getPageHandler(ctx: ServerlessHandlerCtx) {
             res.end()
             return null
           } else {
-            sendPayload(
+            sendRenderResult({
               req,
               res,
-              _nextData ? JSON.stringify(renderOpts.pageData) : result,
-              _nextData ? 'json' : 'html',
-              {
-                generateEtags,
-                poweredByHeader,
-              },
-              {
+              result: _nextData
+                ? RenderResult.fromStatic(JSON.stringify(renderOpts.pageData))
+                : result ?? RenderResult.empty,
+              type: _nextData ? 'json' : 'html',
+              generateEtags,
+              poweredByHeader,
+              options: {
                 private: isPreviewMode || renderOpts.is404Page,
                 stateful: !!getServerSideProps,
                 revalidate: renderOpts.revalidate,
-              }
-            )
+              },
+            })
             return null
           }
         }
@@ -403,7 +400,7 @@ export function getPageHandler(ctx: ServerlessHandlerCtx) {
       }
 
       if (renderMode) return { html: result, renderOpts }
-      return result ? await resultsToString([result]) : null
+      return result ? await result.toUnchunkedString() : null
     } catch (err) {
       if (!parsedUrl!) {
         parsedUrl = parseUrl(req.url!, true)
@@ -465,7 +462,7 @@ export function getPageHandler(ctx: ServerlessHandlerCtx) {
           err: res.statusCode === 404 ? undefined : err,
         })
       )
-      return result2 ? await resultsToString([result2]) : null
+      return result2 ? result2.toUnchunkedString() : null
     }
   }
 
@@ -475,7 +472,11 @@ export function getPageHandler(ctx: ServerlessHandlerCtx) {
       try {
         const html = await renderReqToHTML(req, res)
         if (html) {
-          sendPayload(req, res, html, 'html', {
+          sendRenderResult({
+            req,
+            res,
+            result: RenderResult.fromStatic(html as any),
+            type: 'html',
             generateEtags,
             poweredByHeader,
           })

diff --git a/packages/next/export/worker.ts b/packages/next/export/worker.ts
@@ -3,7 +3,6 @@ import { extname, join, dirname, sep } from 'path'
 import { renderToHTML } from '../server/render'
 import { promises } from 'fs'
 import AmpHtmlValidator from 'next/dist/compiled/amphtml-validator'
-import Observable from 'next/dist/compiled/zen-observable'
 import { loadComponents } from '../server/load-components'
 import { isDynamicRoute } from '../shared/lib/router/utils/is-dynamic'
 import { getRouteMatcher } from '../shared/lib/router/utils/route-matcher'
@@ -19,9 +18,9 @@ import { FontManifest } from '../server/font-utils'
 import { normalizeLocalePath } from '../shared/lib/i18n/normalize-locale-path'
 import { trace } from '../telemetry/trace'
 import { isInAmpMode } from '../shared/lib/amp'
-import { resultsToString } from '../server/utils'
 import { NextConfigComplete } from '../server/config-shared'
 import { setHttpAgentOptions } from '../server/config'
+import RenderResult from '../server/render-result'
 
 const envConfig = require('../shared/lib/runtime-config')
 
@@ -275,7 +274,7 @@ export default async function exportPage({
 
         // if it was auto-exported the HTML is loaded here
         if (typeof mod === 'string') {
-          renderResult = Observable.of(mod)
+          renderResult = RenderResult.fromStatic(mod)
           queryWithAutoExportWarn()
         } else {
           // for non-dynamic SSG pages we should have already
@@ -353,7 +352,7 @@ export default async function exportPage({
         }
 
         if (typeof components.Component === 'string') {
-          renderResult = Observable.of(components.Component)
+          renderResult = RenderResult.fromStatic(components.Component)
           queryWithAutoExportWarn()
         } else {
           /**
@@ -418,7 +417,7 @@ export default async function exportPage({
         }
       }
 
-      const html = renderResult ? await resultsToString([renderResult]) : ''
+      const html = renderResult ? await renderResult.toUnchunkedString() : ''
       if (inAmpMode && !curRenderOpts.ampSkipValidation) {
         if (!results.ssgNotFound) {
           await validateAmp(html, path, curRenderOpts.ampValidatorPath)
@@ -461,7 +460,7 @@ export default async function exportPage({
           }
 
           const ampHtml = ampRenderResult
-            ? await resultsToString([ampRenderResult])
+            ? await ampRenderResult.toUnchunkedString()
             : ''
           if (!curRenderOpts.ampSkipValidation) {
             await validateAmp(ampHtml, page + '?amp=1')

diff --git a/packages/next/server/next-server.ts b/packages/next/server/next-server.ts
@@ -10,7 +10,6 @@ import {
   ParsedUrlQuery,
 } from 'querystring'
 import { format as formatUrl, parse as parseUrl, UrlWithParsedQuery } from 'url'
-import Observable from 'next/dist/compiled/zen-observable'
 import { PrerenderManifest } from '../build'
 import {
   getRedirectStatus,
@@ -77,7 +76,8 @@ import { sendRenderResult, setRevalidateHeaders } from './send-payload'
 import { serveStatic } from './serve-static'
 import { IncrementalCache } from './incremental-cache'
 import { execOnce } from '../shared/lib/utils'
-import { isBlockedPage, RenderResult, resultsToString } from './utils'
+import { isBlockedPage } from './utils'
+import RenderResult from './render-result'
 import { loadEnvConfig } from '@next/env'
 import './node-polyfill-fetch'
 import { PagesManifest } from '../build/webpack/plugins/pages-manifest-plugin'
@@ -1274,9 +1274,7 @@ export default class Server {
       return sendRenderResult({
         req,
         res,
-        resultOrPayload: requireStaticHTML
-          ? await resultsToString([body])
-          : body,
+        result: body,
         type,
         generateEtags,
         poweredByHeader,
@@ -1304,7 +1302,12 @@ export default class Server {
     if (payload === null) {
       return null
     }
-    return resultsToString([payload.body])
+    if (payload.body.isDynamic()) {
+      throw new Error(
+        'invariant: expected a static result. This is a bug in Next.js'
+      )
+    }
+    return payload.body.toUnchunkedString()
   }
 
   public async render(
@@ -1478,8 +1481,8 @@ export default class Server {
     if (typeof components.Component === 'string') {
       return {
         type: 'html',
-        // TODO: Static pages should be written as chunks
-        body: Observable.of(components.Component),
+        // TODO: Static pages should be serialized as RenderResult
+        body: RenderResult.fromStatic(components.Component),
       }
     }
 
@@ -1758,7 +1761,7 @@ export default class Server {
               return {
                 value: {
                   kind: 'PAGE',
-                  html: Observable.of(html),
+                  html: RenderResult.fromStatic(html),
                   pageData: {},
                 },
               }
@@ -1837,7 +1840,7 @@ export default class Server {
       if (isDataReq) {
         return {
           type: 'json',
-          body: Observable.of(JSON.stringify(cachedData.props)),
+          body: RenderResult.fromStatic(JSON.stringify(cachedData.props)),
           revalidateOptions,
         }
       } else {
@@ -1848,7 +1851,7 @@ export default class Server {
       return {
         type: isDataReq ? 'json' : 'html',
         body: isDataReq
-          ? Observable.of(JSON.stringify(cachedData.pageData))
+          ? RenderResult.fromStatic(JSON.stringify(cachedData.pageData))
           : cachedData.html,
         revalidateOptions,
       }
@@ -2088,7 +2091,7 @@ export default class Server {
       }
       return {
         type: 'html',
-        body: Observable.of('Internal Server Error'),
+        body: RenderResult.fromStatic('Internal Server Error'),
       }
     }
   }

diff --git a/packages/next/server/render-result.ts b/packages/next/server/render-result.ts
@@ -0,0 +1,41 @@
+import Observable from 'next/dist/compiled/zen-observable'
+
+export default class RenderResult {
+  _response: string | Observable<string>
+  _dynamic: boolean
+
+  constructor(response: string | Observable<string>, dynamic: boolean) {
+    this._response = response
+    this._dynamic = dynamic
+  }
+
+  async toUnchunkedString(): Promise<string> {
+    if (typeof this._response === 'string') {
+      return this._response
+    }
+    const chunks: string[] = []
+    await this._response.forEach((chunk) => chunks.push(chunk))
+    return chunks.join('')
+  }
+
+  forEach(fn: (chunk: string) => void): Promise<void> {
+    if (typeof this._response === 'string') {
+      const value = this._response
+      return new Promise((resolve) => {
+        fn(value)
+        resolve()
+      })
+    }
+    return this._response.forEach(fn)
+  }
+
+  isDynamic(): boolean {
+    return this._dynamic
+  }
+
+  static fromStatic(value: string): RenderResult {
+    return new RenderResult(value, false)
+  }
+
+  static empty = RenderResult.fromStatic('')
+}