Router.get method in Express is called with the wrong type: The request handler is mistaken for a child application

[hyfhaozero]

Note: I use the typescript
When using the tokenRouter.get method in the auth/token.ts file to define a route handler, the TypeScript compiler throws a type mismatch error. The error message is as follows:

The console messages

auth/token.ts:15:30 - error TS2769: No overload matches this call.
The last overload gave the following error.
Argument of type '(req: Request<ParamsDictionary, any, any, ParsedQs, Record<string, any>>, res: Response<any, Record<string, any>>) => Response<...> | undefined' is not assignable to parameter of type 'Application<Record<string, any>>'.
Type '(req: Request<ParamsDictionary, any, any, ParsedQs, Record<string, any>>, res: Response<any, Record<string, any>>) => Response<...> | undefined' is missing the following properties from type 'Application<Record<string, any>>': init, defaultConfiguration, engine, set, and 63 more.

15 tokenRouter.get('/getToken', function(req: Request, res: Response) {
~~~~~~~~

node_modules/@types/express-serve-static-core/index.d.ts:168:5
168 (path: PathParams, subApplication: Application): T;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The last overload is declared here.

Found 1 error in auth/token.ts:15

Code part

import express, { Request, Response, Router } from 'express';

const tokenRouter: Router = express.Router();

tokenRouter.get('/getToken', function(req: Request, res: Response) {
    // 这里是处理逻辑
    const token = 'example_token';
    return res.json({ token });
});

[bjohansebas]

Could you please provide the version of Express, TypeScript, and the version of the types you are using?

[hyfhaozero]

"@types/express": "^5.0.0",
*express": "^4.21.2",
"typescript": "^5.7.3",

[krzysdz]

"@types/express": "^5.0.0",
"express": "^4.21.2"

I'd suggest sticking with 4.x types for 4.x Express ("@types/express": "^4.17.21")

[krzysdz]

If you are using types for 5.x, then request handlers must return void or Promise<void>, not Response.

More details:

• Version 4.21.0 and older now pulls in types for 5.0.0 that are incompatible. #5987 (comment)
• [@type/express-serve-static-core] Allow express RequestHandler to return Response DefinitelyTyped/DefinitelyTyped#70696

[hyfhaozero]

Thank you,now it's solved by "void"