feat: createMiddleware reports middleware usage

Author: vicb

packages/open-next/src/adapters/middleware.ts

@@ -13,51 +13,51 @@ const resolveOriginResolver = () => {
   const openNextParams = globalThis.openNextConfig.middleware;
   if (typeof openNextParams?.originResolver === "function") {
     return openNextParams.originResolver();
-  } else {
-    return Promise.resolve<OriginResolver>({
-      name: "env",
-      resolve: async (_path: string) => {
-        try {
-          const origin = JSON.parse(
-            process.env.OPEN_NEXT_ORIGIN ?? "{}",
-          ) as Record<string, Origin>;
-          for (const [key, value] of Object.entries(
-            globalThis.openNextConfig.functions ?? {},
-          ).filter(([key]) => key !== "default")) {
-            if (
-              value.patterns.some((pattern) => {
-                // Convert cloudfront pattern to regex
-                return new RegExp(
-                  // transform glob pattern to regex
-                  "/" +
-                    pattern
-                      .replace(/\*\*/g, "(.*)")
-                      .replace(/\*/g, "([^/]*)")
-                      .replace(/\//g, "\\/")
-                      .replace(/\?/g, "."),
-                ).test(_path);
-              })
-            ) {
-              debug("Using origin", key, value.patterns);
-              return origin[key];
-            }
-          }
-          if (_path.startsWith("/_next/image") && origin["imageOptimizer"]) {
-            debug("Using origin", "imageOptimizer", _path);
-            return origin["imageOptimizer"];
-          }
-          if (origin["default"]) {
-            debug("Using default origin", origin["default"], _path);
-            return origin["default"];
+  }
+
+  return Promise.resolve<OriginResolver>({
+    name: "env",
+    resolve: async (_path: string) => {
+      try {
+        const origin = JSON.parse(
+          process.env.OPEN_NEXT_ORIGIN ?? "{}",
+        ) as Record<string, Origin>;
+        for (const [key, value] of Object.entries(
+          globalThis.openNextConfig.functions ?? {},
+        ).filter(([key]) => key !== "default")) {
+          if (
+            value.patterns.some((pattern) => {
+              // Convert cloudfront pattern to regex
+              return new RegExp(
+                // transform glob pattern to regex
+                "/" +
+                  pattern
+                    .replace(/\*\*/g, "(.*)")
+                    .replace(/\*/g, "([^/]*)")
+                    .replace(/\//g, "\\/")
+                    .replace(/\?/g, "."),
+              ).test(_path);
+            })
+          ) {
+            debug("Using origin", key, value.patterns);
+            return origin[key];
           }
-          return false as const;
-        } catch (e) {
-          error("Error while resolving origin", e);
-          return false as const;
         }
-      },
-    });
-  }
+        if (_path.startsWith("/_next/image") && origin["imageOptimizer"]) {
+          debug("Using origin", "imageOptimizer", _path);
+          return origin["imageOptimizer"];
+        }
+        if (origin["default"]) {
+          debug("Using default origin", origin["default"], _path);
+          return origin["default"];
+        }
+        return false as const;
+      } catch (e) {
+        error("Error while resolving origin", e);
+        return false as const;
+      }
+    },
+  });
 };
 
 globalThis.internalFetch = fetch;
@@ -93,10 +93,10 @@ const defaultHandler = async (internalEvent: InternalEvent) => {
       origin,
       isISR: result.isISR,
     };
-  } else {
-    debug("Middleware response", result);
-    return result;
   }
+
+  debug("Middleware response", result);
+  return result;
 };
 
 export const handler = await createGenericHandler({

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

@@ -6,6 +6,12 @@ import { type MiddlewareManifest } from "../types/next-types.js";
 import { buildEdgeBundle } from "./edge/createEdgeBundle.js";
 import * as buildHelper from "./helper.js";
 
+/**
+ * Compiles the middleware bundle.
+ *
+ * @param options Build Options.
+ * @returns Whether the app uses a Middleware.
+ */
 export async function createMiddleware(options: buildHelper.BuildOptions) {
   logger.info(`Bundling middleware function...`);
 
@@ -21,7 +27,7 @@ export async function createMiddleware(options: buildHelper.BuildOptions) {
 
   const entry = middlewareManifest.middleware["/"];
   if (!entry) {
-    return;
+    return { useMiddleware: false };
   }
 
   // Create output folder
@@ -70,4 +76,6 @@ export async function createMiddleware(options: buildHelper.BuildOptions) {
       onlyBuildOnce: true,
     });
   }
+
+  return { useMiddleware: true };
 }

packages/open-next/src/converters/aws-cloudfront.ts

@@ -149,12 +149,9 @@ async function convertToCloudFrontRequestResult(
   result: InternalResult | MiddlewareEvent,
   originalRequest: CloudFrontRequestEvent,
 ): Promise<CloudFrontRequestResult> {
-  let responseHeaders =
-    result.type === "middleware"
-      ? result.internalEvent.headers
-      : result.headers;
   if (result.type === "middleware") {
     const { method, clientIp, origin } = originalRequest.Records[0].cf.request;
+    const responseHeaders = result.internalEvent.headers;
 
     // Handle external rewrite
     if (result.isExternalRewrite) {
@@ -215,6 +212,7 @@ async function convertToCloudFrontRequestResult(
   }
 
   const body = await fromReadableStream(result.body, result.isBase64Encoded);
+  const responseHeaders = result.headers;
 
   const response: CloudFrontRequestResult = {
     status: result.statusCode.toString(),
@@ -223,6 +221,7 @@ async function convertToCloudFrontRequestResult(
     bodyEncoding: result.isBase64Encoded ? "base64" : "text",
     body,
   };
+
   debug(response);
   return response;
 }