I have problem with Zod’s coerce method. I know that by default req.params are string, but I’ve thought that coerce method would change it to number during parsing, so it would work.

ValidateSchema.ts

import z from "zod";

const toNumber = z.coerce.number();
const toDate = z.coerce.date();

export const getWeatherForLocationSchema = z.object({
  params: z.object({
lat: z.string().pipe(z.coerce.number()),
lon: z.string().pipe(z.coerce.number()),
    // lat: z.string().transform((data) => +data),
    // lat: z.string(),
    // lon: z.string(),
  }),
});

export type getCurrentWeatherForLocationRequest = z.infer<
  typeof getWeatherForLocationSchema
>;

WeatherController.ts

  getCurrentWeatherForLocation = async (
    req: ParsedRequest<getCurrentWeatherForLocationRequest>,
    res: Response
  ) => {
    const lat = req.params.lat;
    const lon = req.params.lon;
    console.log(typeof lat);
    const weather = await this.weatherService.getCurrentWeatherForLocation(
      lat,
      lon
    );
    res.status(200).json(weather);
  };

WeatherRouter.ts

  "/weather/locations/:lat/:lon",
  validatorMiddleware(getWeatherForLocationSchema),
  weatherController.getCurrentWeatherForLocation
);

ValidatorMiddleware.ts

import { SafeParseReturnType, Schema, ZodError } from "zod";
import { ExpressAnyRequestData } from "../interfaces/ApiTypes";
import { NextFunction, Request, Response } from "express";
import { ParsedQs } from "qs";

export function validateExpressRequest<T extends ExpressAnyRequestData>(
  schema: Schema<T>,
  req: Request
): T {
  const { params, query, body } = req;

  const dataToParse: {
    params?: Record<string, string>;
    query?: ParsedQs;
    body?: unknown;
  } = {};

  if (Object.keys(params).length) {
    dataToParse.params = params;
  }

  if (query && Object.keys(query).length) {
    dataToParse.query = query;
  }

  if (Object.keys(body).length) {
    dataToParse.body = body;
  }

  const validationResult: SafeParseReturnType<
    {
      params?: Record<string, string>;
      query?: ParsedQs;
      body?: unknown;
    },
    { params?: any; query?: any; body?: any }
  > = schema.safeParse(dataToParse);

  if (!validationResult.success) {
    throw new ZodError(validationResult.error.issues);
  }
  return {
    query: validationResult.data.query,
    params: validationResult.data.params,
    body: validationResult.data.body,
  } as T;
}

export function validatorMiddleware(
  schema: Schema
): (req: Request, res: Response, next: NextFunction) => void {
  return (req: Request, res: Response, next: NextFunction): void => {
    try {
      const result = validateExpressRequest(schema, req);

      const { params, query, body } = result;
      req.query = query;
      req.params = params;
      req.body = body;

      return next();
    } catch (e) {
      return next(e);
    }
  };
}

My error:

usr/local/lib/node_modules/ts-node/src/index.ts:859
    return new TSError(diagnosticText, diagnosticCodes, diagnostics);
           ^
TSError: ⨯ Unable to compile TypeScript:
src/domains/weather/WeatherRouter.ts:18:3 - error TS2769: No overload matches this call.
  The last overload gave the following error.
    Argument of type '(req: ParsedRequest<getCurrentWeatherForLocationRequest>, res: Response) => Promise<void>' is not assignable to parameter of type 'RequestHandlerParams<ParamsDictionary, any, unknown, ParsedQs, {}>'.
      Type '(req: ParsedRequest<getCurrentWeatherForLocationRequest>, res: Response) => Promise<void>' is not assignable to type 'RequestHandler<ParamsDictionary, any, unknown, ParsedQs, {}>'.
        Types of parameters 'req' and 'req' are incompatible.
          Type 'Request<ParamsDictionary, any, unknown, ParsedQs, {}>' is not assignable to type 'ParsedRequest<{ params: { lat: number; lon: number; }; }>'.
            Types of property 'params' are incompatible.
              Type 'ParamsDictionary' is missing the following properties from type '{ lat: number; lon: number; }': lat, lon

18   weatherController.getCurrentWeatherForLocation
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  node_modules/@types/express-serve-static-core/index.d.ts:153:5
    153     <
            ~
    154         P = ParamsDictionary,
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    ... 
    162         ...handlers: Array<RequestHandlerParams<P, ResBody, ReqBody, ReqQuery, LocalsObj>>
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    163     ): T;
        ~~~~~~~~~
    The last overload is declared here.

    at createTSError (/usr/local/lib/node_modules/ts-node/src/index.ts:859:12)
    at reportTSError (/usr/local/lib/node_modules/ts-node/src/index.ts:863:19)
    at getOutput (/usr/local/lib/node_modules/ts-node/src/index.ts:1077:36)
    at Object.compile (/usr/local/lib/node_modules/ts-node/src/index.ts:1433:41)
    at Module.m._compile (/usr/local/lib/node_modules/ts-node/src/index.ts:1617:30)
    at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
    at Object.require.extensions.<computed> [as .ts] (/usr/local/lib/node_modules/ts-node/src/index.ts:1621:12)
    at Module.load (node:internal/modules/cjs/loader:1119:32)
    at Function.Module._load (node:internal/modules/cjs/loader:960:12)
    at Module.require (node:internal/modules/cjs/loader:1143:19) {
  diagnosticCodes: [ 2769 ]
}
[nodemon] app crashed - waiting for file changes before starting...

I want to add conversion type without need to change in controller method. I’ve tried modifying params in validatorMiddleware to add Record <string, number>, using zod with pipe, transform, coerce and nothing worked.