Fix cloudflare env (#514)

* fix cookies improperly set on node

* fix issue with env in cloudflare

* fix cookies not properly set when set both in the middleware and a route

* bundle everything for edge into one file

* avoid bundling in one file when middleware is inside server function

* added option for headers priority

* Create weak-hotels-thank.md

Author: conico974

.changeset/weak-hotels-thank.md

@@ -0,0 +1,8 @@
+---
+"@opennextjs/aws": patch
+---
+
+Fix cloudflare env
+Fix an issue with cookies and the node wrapper
+Fix some issue with cookies being not properly set when set both in the routing layer and the route itself
+Added option for headers priority

packages/open-next/src/build.ts

@@ -759,12 +759,14 @@ async function createMiddleware() {
       overrides: config.middleware?.override,
       defaultConverter: "aws-cloudfront",
       includeCache: config.dangerous?.enableCacheInterception,
+      additionalExternals: config.edgeExternals,
     });
   } else {
     await buildEdgeBundle({
       entrypoint: path.join(__dirname, "core", "edgeFunctionHandler.js"),
       outfile: path.join(outputDir, ".build", "middleware.mjs"),
       ...commonMiddlewareOptions,
+      onlyBuildOnce: true,
     });
   }
 }

packages/open-next/src/build/createServerBundle.ts

@@ -51,7 +51,7 @@ export async function createServerBundle(
     const routes = fnOptions.routes;
     routes.forEach((route) => foundRoutes.add(route));
     if (fnOptions.runtime === "edge") {
-      await generateEdgeBundle(name, options, fnOptions);
+      await generateEdgeBundle(name, config, options, fnOptions);
     } else {
       await generateBundle(name, config, options, fnOptions);
     }

packages/open-next/src/build/edge/createEdgeBundle.ts

@@ -1,11 +1,13 @@
 import { mkdirSync } from "node:fs";
 import url from "node:url";
 
+import { build } from "esbuild";
 import fs from "fs";
 import path from "path";
 import { MiddlewareInfo, MiddlewareManifest } from "types/next-types";
 import {
   IncludedConverter,
+  OpenNextConfig,
   OverrideOptions,
   RouteTemplate,
   SplittedFunctionOptions,
@@ -29,6 +31,8 @@ interface BuildEdgeBundleOptions {
   defaultConverter?: IncludedConverter;
   additionalInject?: string;
   includeCache?: boolean;
+  additionalExternals?: string[];
+  onlyBuildOnce?: boolean;
 }
 
 export async function buildEdgeBundle({
@@ -41,7 +45,13 @@ export async function buildEdgeBundle({
   overrides,
   additionalInject,
   includeCache,
+  additionalExternals,
+  onlyBuildOnce,
 }: BuildEdgeBundleOptions) {
+  const isInCloudfare =
+    typeof overrides?.wrapper === "string"
+      ? overrides.wrapper === "cloudflare"
+      : (await overrides?.wrapper?.())?.edgeRuntime;
   await esbuildAsync(
     {
       entryPoints: [entrypoint],
@@ -93,7 +103,7 @@ export async function buildEdgeBundle({
             "../../core",
             "edgeFunctionHandler.js",
           ),
-          isInCloudfare: overrides?.wrapper === "cloudflare",
+          isInCloudfare,
         }),
       ],
       treeShaking: true,
@@ -106,8 +116,13 @@ export async function buildEdgeBundle({
       mainFields: ["module", "main"],
       banner: {
         js: `
+import {Buffer} from "node:buffer";
+globalThis.Buffer = Buffer;
+
+import {AsyncLocalStorage} from "node:async_hooks";
+globalThis.AsyncLocalStorage = AsyncLocalStorage;
   ${
-    overrides?.wrapper === "cloudflare"
+    isInCloudfare
       ? ""
       : `
   const require = (await import("node:module")).createRequire(import.meta.url);
@@ -129,12 +144,30 @@ export async function buildEdgeBundle({
     },
     options,
   );
+
+  if (!onlyBuildOnce) {
+    await build({
+      entryPoints: [outfile],
+      outfile,
+      allowOverwrite: true,
+      bundle: true,
+      minify: true,
+      platform: "node",
+      format: "esm",
+      conditions: ["workerd", "worker", "browser"],
+      external: ["node:*", ...(additionalExternals ?? [])],
+      banner: {
+        js: 'import * as process from "node:process";',
+      },
+    });
+  }
 }
 
 export function copyMiddlewareAssetsAndWasm({}) {}
 
 export async function generateEdgeBundle(
   name: string,
+  config: OpenNextConfig,
   options: BuildOptions,
   fnOptions: SplittedFunctionOptions,
 ) {
@@ -193,5 +226,6 @@ export async function generateEdgeBundle(
     outfile: path.join(outputPath, "index.mjs"),
     options,
     overrides: fnOptions.override,
+    additionalExternals: config.edgeExternals,
   });
 }

packages/open-next/src/core/createMainHandler.ts

@@ -25,6 +25,7 @@ declare global {
     requestId: string;
     pendingPromiseRunner: DetachedPromiseRunner;
     isISRRevalidation?: boolean;
+    mergeHeadersPriority?: "middleware" | "handler";
   }>;
 }
 

packages/open-next/src/core/requestHandler.ts

@@ -19,6 +19,7 @@ globalThis.__als = new AsyncLocalStorage<{
   requestId: string;
   pendingPromiseRunner: DetachedPromiseRunner;
   isISRRevalidation?: boolean;
+  mergeHeadersPriority?: "middleware" | "handler";
 }>();
 
 patchAsyncStorage();
@@ -103,8 +104,19 @@ export async function openNextHandler(
     const pendingPromiseRunner: DetachedPromiseRunner =
       new DetachedPromiseRunner();
     const isISRRevalidation = headers["x-isr"] === "1";
+    const mergeHeadersPriority = globalThis.openNextConfig.dangerous
+      ?.headersAndCookiesPriority
+      ? globalThis.openNextConfig.dangerous.headersAndCookiesPriority(
+          preprocessedEvent,
+        )
+      : "middleware";
     const internalResult = await globalThis.__als.run(
-      { requestId, pendingPromiseRunner, isISRRevalidation },
+      {
+        requestId,
+        pendingPromiseRunner,
+        isISRRevalidation,
+        mergeHeadersPriority,
+      },
       async () => {
         const preprocessedResult = preprocessResult as MiddlewareOutputEvent;
         const req = new IncomingMessage(reqProps);

packages/open-next/src/http/openNextResponse.ts

@@ -82,11 +82,6 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     private initialHeaders?: OutgoingHttpHeaders,
   ) {
     super();
-    if (initialHeaders && initialHeaders[SET_COOKIE_HEADER]) {
-      this._cookies = parseCookies(
-        initialHeaders[SET_COOKIE_HEADER] as string | string[],
-      ) as string[];
-    }
     this.once("finish", () => {
       if (!this.headersSent) {
         this.flushHeaders();
@@ -164,28 +159,43 @@ export class OpenNextNodeResponse extends Transform implements ServerResponse {
     this.headersSent = true;
     // Initial headers should be merged with the new headers
     // These initial headers are the one created either in the middleware or in next.config.js
-    // We choose to override response headers with middleware headers
-    // This is different than the default behavior in next.js, but it allows more customization
-    // TODO: We probably want to change this behavior in the future to follow next
-    // We could add a prefix header that would allow to force the middleware headers
-    // Something like open-next-force-cache-control would override the cache-control header
+    const mergeHeadersPriority =
+      globalThis.__als?.getStore()?.mergeHeadersPriority ?? "middleware";
     if (this.initialHeaders) {
-      this.headers = {
-        ...this.headers,
-        ...this.initialHeaders,
-      };
+      this.headers =
+        mergeHeadersPriority === "middleware"
+          ? {
+              ...this.headers,
+              ...this.initialHeaders,
+            }
+          : {
+              ...this.initialHeaders,
+              ...this.headers,
+            };
+      const initialCookies = parseCookies(
+        (this.initialHeaders[SET_COOKIE_HEADER] as string | string[]) ?? [],
+      ) as string[];
+      this._cookies =
+        mergeHeadersPriority === "middleware"
+          ? [...this._cookies, ...initialCookies]
+          : [...initialCookies, ...this._cookies];
     }
     this.fixHeaders(this.headers);
-    if (this._cookies.length > 0) {
-      // For cookies we cannot do the same as for other headers
-      this.headers[SET_COOKIE_HEADER] = this._cookies;
-    }
+
+    // We need to fix the set-cookie header here
+    this.headers[SET_COOKIE_HEADER] = this._cookies;
+
+    const parsedHeaders = parseHeaders(this.headers);
+
+    // We need to remove the set-cookie header from the parsed headers because
+    // it does not handle multiple set-cookie headers properly
+    delete parsedHeaders[SET_COOKIE_HEADER];
 
     if (this.streamCreator) {
       this.responseStream = this.streamCreator?.writeHeaders({
         statusCode: this.statusCode ?? 200,
         cookies: this._cookies,
-        headers: parseHeaders(this.headers),
+        headers: parsedHeaders,
       });
       this.pipe(this.responseStream);
     }

packages/open-next/src/plugins/edge.ts

@@ -92,16 +92,8 @@ export function openNextEdgePlugins({
         contents = `
 globalThis._ENTRIES = {};
 globalThis.self = globalThis;
-if(!globalThis.process){
-  globalThis.process = {env: {}};
-}
 globalThis._ROUTES = ${JSON.stringify(routes)};
 
-import {Buffer} from "node:buffer";
-globalThis.Buffer = Buffer;
-
-import {AsyncLocalStorage} from "node:async_hooks";
-globalThis.AsyncLocalStorage = AsyncLocalStorage;
 ${
   isInCloudfare
     ? ``

packages/open-next/src/types/open-next.ts

@@ -49,6 +49,14 @@ export interface DangerousOptions {
    * @default false
    */
   enableCacheInterception?: boolean;
+  /**
+   * Function to determine which headers or cookies takes precedence.
+   * By default, the middleware headers and cookies will override the handler headers and cookies.
+   * This is executed for every request and after next config headers and middleware has executed.
+   */
+  headersAndCookiesPriority?: (
+    event: InternalEvent,
+  ) => "middleware" | "handler";
 }
 
 export type BaseOverride = {
@@ -83,6 +91,7 @@ export type Wrapper<
 > = BaseOverride & {
   wrapper: WrapperHandler<E, R>;
   supportStreaming: boolean;
+  edgeRuntime?: boolean;
 };
 
 export type Warmer = BaseOverride & {

packages/open-next/src/wrappers/aws-lambda-streaming.ts

@@ -35,8 +35,6 @@ const handler: WrapperHandler = async (handler, converter) =>
         return;
       }
 
-      let headersWritten = false;
-
       const internalEvent = await converter.convertFrom(event);
 
       //Handle compression
@@ -84,14 +82,12 @@ const handler: WrapperHandler = async (handler, converter) =>
             "application/vnd.awslambda.http-integration-response",
           );
           _prelude.headers["content-encoding"] = contentEncoding;
-          // We need to remove the set-cookie header as otherwise it will be set twice, once with the cookies in the prelude, and a second time with the set-cookie headers
-          delete _prelude.headers["set-cookie"];
+
           const prelude = JSON.stringify(_prelude);
 
           responseStream.write(prelude);
 
           responseStream.write(new Uint8Array(8));
-          headersWritten = true;
 
           return compressedStream ?? responseStream;
         },