fix: middleware type (#922)

Co-authored-by: conico974 <nicodorseuil@yahoo.fr>

Author: vicb

.changeset/slimy-turkeys-smoke.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+fix: middleware configuration type

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

@@ -1,4 +1,5 @@
 import type {
+  ExternalMiddlewareConfig,
   InternalEvent,
   InternalResult,
   MiddlewareResult,
@@ -30,22 +31,30 @@ const defaultHandler = async (
   internalEvent: InternalEvent,
   options?: OpenNextHandlerOptions,
 ): Promise<InternalResult | MiddlewareResult> => {
-  const config = globalThis.openNextConfig.middleware;
-  const originResolver = await resolveOriginResolver(config?.originResolver);
+  // We know that the middleware is external when this adapter is used
+  const middlewareConfig = globalThis.openNextConfig
+    .middleware as ExternalMiddlewareConfig;
+  const originResolver = await resolveOriginResolver(
+    middlewareConfig?.originResolver,
+  );
 
   const externalRequestProxy = await resolveProxyRequest(
-    config?.override?.proxyExternalRequest,
+    middlewareConfig?.override?.proxyExternalRequest,
   );
 
-  const assetResolver = await resolveAssetResolver(config?.assetResolver);
+  const assetResolver = await resolveAssetResolver(
+    middlewareConfig?.assetResolver,
+  );
 
   //#override includeCacheInMiddleware
-  globalThis.tagCache = await resolveTagCache(config?.override?.tagCache);
+  globalThis.tagCache = await resolveTagCache(
+    middlewareConfig?.override?.tagCache,
+  );
 
-  globalThis.queue = await resolveQueue(config?.override?.queue);
+  globalThis.queue = await resolveQueue(middlewareConfig?.override?.queue);
 
   globalThis.incrementalCache = await resolveIncrementalCache(
-    config?.override?.incrementalCache,
+    middlewareConfig?.override?.incrementalCache,
   );
   //#endOverride
 

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

@@ -3,6 +3,7 @@ import path from "node:path";
 import type {
   BaseOverride,
   DefaultOverrideOptions,
+  ExternalMiddlewareConfig,
   FunctionOptions,
   LazyLoadedOverride,
   OverrideOptions,
@@ -164,14 +165,16 @@ export async function generateOutput(options: BuildOptions) {
   const edgeFunctions: OpenNextOutput["edgeFunctions"] = {};
   const isExternalMiddleware = config.middleware?.external ?? false;
   if (isExternalMiddleware) {
+    const middlewareConfig = options.config
+      .middleware as ExternalMiddlewareConfig;
     edgeFunctions.middleware = {
       bundle: ".open-next/middleware",
       handler: "handler.handler",
       pathResolver: await extractOverrideName(
         "pattern-env",
-        config.middleware!.originResolver,
+        middlewareConfig.originResolver,
       ),
-      ...(await extractOverrideFn(config.middleware?.override)),
+      ...(await extractOverrideFn(middlewareConfig.override)),
     };
   }
   // Add edge functions

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

@@ -109,7 +109,9 @@ export function validateConfig(config: OpenNextConfig) {
     );
   }
   validateFunctionOptions(config.imageOptimization ?? {});
-  validateFunctionOptions(config.middleware ?? {});
+  if (config.middleware?.external === true) {
+    validateFunctionOptions(config.middleware ?? {});
+  }
   //@ts-expect-error - Revalidate custom wrapper type is different
   validateFunctionOptions(config.revalidate ?? {});
   //@ts-expect-error - Warmer custom wrapper type is different

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

@@ -37,8 +37,11 @@ export async function createGenericHandler<
   );
 
   globalThis.openNextConfig = config;
-  const override = config[handler.type]
-    ?.override as any as DefaultOverrideOptions<E, R>;
+  const handlerConfig = config[handler.type];
+  const override =
+    handlerConfig && "override" in handlerConfig
+      ? (handlerConfig.override as any as DefaultOverrideOptions<E, R>)
+      : undefined;
 
   // From the config, we create the converter
   const converter = await resolveConverter<E, R>(override?.converter);

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

@@ -1,6 +1,7 @@
 import type {
   BaseEventOrResult,
   DefaultOverrideOptions,
+  ExternalMiddlewareConfig,
   InternalEvent,
   InternalResult,
   OpenNextConfig,
@@ -105,9 +106,7 @@ export async function resolveImageLoader(
  * @__PURE__
  */
 export async function resolveOriginResolver(
-  originResolver: RemoveUndefined<
-    OpenNextConfig["middleware"]
-  >["originResolver"],
+  originResolver: RemoveUndefined<ExternalMiddlewareConfig>["originResolver"],
 ) {
   if (typeof originResolver === "function") {
     return originResolver();

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

@@ -363,20 +363,24 @@ export interface SplittedFunctionOptions extends FunctionOptions {
   patterns: string[];
 }
 
-export interface OpenNextConfig {
-  default: FunctionOptions;
-  functions?: Record<string, SplittedFunctionOptions>;
-
+/**
+ * MiddlewareConfig that applies to both external and internal middlewares
+ *
+ * Note: this type is internal and included in both `ExternalMiddlewareConfig` and `InternalMiddlewareConfig`
+ */
+type CommonMiddlewareConfig = {
   /**
-   * Override the default middleware
-   * If you set this options, the middleware need to be deployed separately.
-   * It supports both edge and node runtime.
-   * @default undefined
+   * The assetResolver is used to resolve assets in the routing layer.
+   *
+   * @default "dummy"
    */
-  middleware?: DefaultFunctionOptions & {
-    //We force the middleware to be a function
-    external: true;
+  assetResolver?: IncludedAssetResolver | LazyLoadedOverride<AssetResolver>;
+};
 
+/** MiddlewareConfig that applies to external middlewares only */
+export type ExternalMiddlewareConfig = DefaultFunctionOptions &
+  CommonMiddlewareConfig & {
+    external: true;
     /**
      * The runtime used by next for the middleware.
      * @default "edge"
@@ -400,15 +404,25 @@ export interface OpenNextConfig {
     originResolver?:
       | IncludedOriginResolver
       | LazyLoadedOverride<OriginResolver>;
-
-    /**
-     * The assetResolver is used to resolve assets in the routing layer.
-     *
-     * @default "dummy"
-     */
-    assetResolver?: IncludedAssetResolver | LazyLoadedOverride<AssetResolver>;
   };
 
+/** MiddlewareConfig that applies to internal middlewares only */
+export type InternalMiddlewareConfig = {
+  external: false;
+} & CommonMiddlewareConfig;
+
+export interface OpenNextConfig {
+  default: FunctionOptions;
+  functions?: Record<string, SplittedFunctionOptions>;
+
+  /**
+   * Override the default middleware
+   * When `external` is true, the middleware need to be deployed separately.
+   * It supports both edge and node runtime.
+   * @default undefined - Which is equivalent to `external: false`
+   */
+  middleware?: ExternalMiddlewareConfig | InternalMiddlewareConfig;
+
   /**
    * Override the default warmer
    * By default, works for lambda only.