fix(cloudflare/workers): drain pre-response handlers in serveWebRequest

[Mkassabov]

HttpMiddleware.cors() (and any other middleware that registers a preResponseHandler for non-OPTIONS requests) was a no-op on real responses inside a Cloudflare.Worker — only OPTIONS preflights short-circuited with CORS headers. serveWebRequest ran the handler and converted the result straight to a web Response, never draining the pre-response queue.

Run the handler through effect's public HttpEffect.toHandled so the registered pre-response handler chain fires before the response is converted. scopeTransferToStream keeps streaming bodies' scopes closing on stream end.

-    const response = yield* handler.pipe(
-      Effect.provideService(HttpServerRequest.HttpServerRequest, request),
-      Effect.provideService(Request, webRequest as any),
-      Effect.catchCause(...),
-    );
-    return HttpServerResponse.toWeb(response, { context: yield* Effect.context() });
+    const httpApp = HttpEffectModule.toHandled(handler, (_req, response) => {
+      const transferred = HttpEffectModule.scopeTransferToStream(response);
+      resume(Effect.succeed(HttpServerResponse.toWeb(transferred, { context: parentContext })));
+      return Effect.void;
+    });
+    httpApp.pipe(
+      Effect.provideService(HttpServerRequest.HttpServerRequest, request),
+      Effect.provideService(Request, webRequest as any),
+      Effect.provide(parentContext),
+      Effect.runFork,
+    );

Verified against the repro from #175: both OPTIONS preflight and GET now carry Access-Control-Allow-Origin.

Fixes #175

[alchemy-version-bot]

Install the packages built from this commit:

alchemy

bun add alchemy@https://pkg.ing/alchemy/245e617

@alchemy.run/better-auth

bun add @alchemy.run/better-auth@https://pkg.ing/@alchemy.run/better-auth/245e617

@alchemy.run/pr-package

bun add @alchemy.run/pr-package@https://pkg.ing/@alchemy.run/pr-package/245e617