r is not a function when wrapping API route with a function and use server

[Floriferous]

Link to the code that reproduces this issue

https://github.com/Floriferous/next-api-bug

To Reproduce

• Clone this repo: https://github.com/Floriferous/next-api-bug
• Run it with npm run dev
• Visit '/' with your browser
• Notice the error r is not a function in the terminal
• When you remove 'use server', the API route starts working again

Current vs. Expected behavior

This is a reopening of #67833, as I was still experiencing the bug even after doing what @icyJoseph suggested. The issue is more complex, as it happens because I had 'use server' at the top of the wrapper function's file. I would expect to have some other kind of error, or something that helps in understanding that this pattern is not allowed.

When adding use server to a file, it seems to do weird things with your functions, and create really difficult to understand errors and error stacks:

I've defined 2 files:

// my API route

import { apiRoute } from "../helpers";

export const GET = apiRoute(async () => {
  console.log('wut?');
  
  return new Response({ hello: 'world' });
})

// The apiRoute function
'use server'; // This is the mistake

export const apiRoute =
  (handler: any) =>
  async (...args) => {
    logStuff();
    return handler(...args);
  };

Using these 2 together is somehow not allowed, and the error message does not make much sense.

Here's the error stack:

 ⨯ TypeError: r is not a function
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:55044
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/trace/tracer.js:140:36
    at NoopContextManager.with (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:7062)
    at ContextAPI.with (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:518)
    at NoopTracer.startActiveSpan (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:18093)
    at ProxyTracer.startActiveSpan (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:18854)
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/trace/tracer.js:122:103
    at NoopContextManager.with (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:7062)
    at ContextAPI.with (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:518)
    at NextTracerImpl.trace (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/trace/tracer.js:122:28)
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:47853
    at AsyncLocalStorage.run (node:async_hooks:346:14)
    at Object.wrap (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:40244)
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:46429
    at AsyncLocalStorage.run (node:async_hooks:346:14)
    at Object.wrap (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:37583)
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:46391
    at AsyncLocalStorage.run (node:async_hooks:346:14)
    at ek.execute (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:45838)
    at ek.handle (/Users/flo/dev/next-api-bug/node_modules/next/dist/compiled/next-server/app-route.runtime.dev.js:6:56303)
    at doRender (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1377:60)
    at cacheEntry.responseCache.get.routeKind (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1599:34)
    at ResponseCache.get (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/response-cache/index.js:49:26)
    at DevServer.renderToResponseWithComponentsImpl (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1507:53)
    at /Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1002:121
    at NextTracerImpl.trace (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/trace/tracer.js:105:20)
    at DevServer.renderToResponseWithComponents (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1002:41)
    at DevServer.renderPageComponent (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1931:35)
    at async DevServer.renderToResponseImpl (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:1969:32)
    at async DevServer.pipeImpl (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:920:25)
    at async NextNodeServer.handleCatchallRenderRequest (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/next-server.js:272:17)
    at async DevServer.handleRequestImpl (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/base-server.js:816:17)
    at async /Users/flo/dev/next-api-bug/node_modules/next/dist/server/dev/next-dev-server.js:339:20
    at async Span.traceAsyncFn (/Users/flo/dev/next-api-bug/node_modules/next/dist/trace/trace.js:154:20)
    at async DevServer.handleRequest (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/dev/next-dev-server.js:336:24)
    at async invokeRender (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/router-server.js:174:21)
    at async handleRequest (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/router-server.js:353:24)
    at async requestHandlerImpl (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/router-server.js:377:13)
    at async Server.requestListener (/Users/flo/dev/next-api-bug/node_modules/next/dist/server/lib/start-server.js:141:13)
 GET /api/stuff 500 in 153ms

Provide environment information

Operating System:
  Platform: darwin
  Arch: x64
  Version: Darwin Kernel Version 23.5.0: Wed May  1 20:19:05 PDT 2024; root:xnu-10063.121.3~5/RELEASE_ARM64_T8112
  Available memory (MB): 24576
  Available CPU cores: 8
Binaries:
  Node: 20.11.0
  npm: 10.7.0
  Yarn: 1.21.1
  pnpm: N/A
Relevant Packages:
  next: 14.2.5 // Latest available version is detected (14.2.5).
  eslint-config-next: 14.2.5
  react: 18.3.1
  react-dom: 18.3.1
  typescript: 5.5.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Developer Experience

Which stage(s) are affected? (Select all that apply)

next dev (local)

Additional context

No response

[icyJoseph]

Yeah, I'd say, refactor by moving your helper function into a module without the use server annotation.

There's a longer explanation, but I'm out of the - city... In short, server actions are asynchronous because they represent work triggered on the server, by the client.

• https://react.dev/reference/rsc/use-server#caveats

Because the underlying network calls are always asynchronous, 'use server' can only be used on async functions.