typed-express.js

// @flow

import type { $Request, $Response, Middleware, NextFunction, Router } from 'express'

type Path = express$Path | express$Path[]

export type TypedMiddleware<A> =
  | ((req: $Request & A, res: $Response, next: NextFunction) => mixed)
  | ((error: Error, req: Request & A, res: $Response, next: NextFunction) => mixed)

export const TypedRouter = {
  get2<R: Router, A1, A2>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2))
  },

  get3<R: Router, A1, A2, A3>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2), coerce(middleware3))
  },

  get4<R: Router, A1, A2, A3, A4>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4))
  },

  get5<R: Router, A1, A2, A3, A4, A5>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5))
  },

  get6<R: Router, A1, A2, A3, A4, A5, A6>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>, middleware6: TypedMiddleware<A6>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5), coerce(middleware6))
  },

  get7<R: Router, A1, A2, A3, A4, A5, A6, A7>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>, middleware6: TypedMiddleware<A6>, middleware7: TypedMiddleware<A7>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5), coerce(middleware6), coerce(middleware7))
  },

  get8<R: Router, A1, A2, A3, A4, A5, A6, A7, A8>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>, middleware6: TypedMiddleware<A6>, middleware7: TypedMiddleware<A7>, middleware8: TypedMiddleware<A8>): R {
    return router.get(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5), coerce(middleware6), coerce(middleware7), coerce(middleware8))
  },

  use2<R: Router, A1, A2>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2))
  },

  use3<R: Router, A1, A2, A3>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2), coerce(middleware3))
  },

  use4<R: Router, A1, A2, A3, A4>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4))
  },

  use5<R: Router, A1, A2, A3, A4, A5>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5))
  },

  use6<R: Router, A1, A2, A3, A4, A5, A6>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>, middleware6: TypedMiddleware<A6>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5), coerce(middleware6))
  },

  use7<R: Router, A1, A2, A3, A4, A5, A6, A7>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>, middleware6: TypedMiddleware<A6>, middleware7: TypedMiddleware<A7>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5), coerce(middleware6), coerce(middleware7))
  },

  use8<R: Router, A1, A2, A3, A4, A5, A6, A7, A8>(router: R, path: Path, middleware1: TypedMiddleware<A1>, middleware2: TypedMiddleware<A2>, middleware3: TypedMiddleware<A3>, middleware4: TypedMiddleware<A4>, middleware5: TypedMiddleware<A5>, middleware6: TypedMiddleware<A6>, middleware7: TypedMiddleware<A7>, middleware8: TypedMiddleware<A8>): R {
    return router.use(path, coerce(middleware1), coerce(middleware2), coerce(middleware3), coerce(middleware4), coerce(middleware5), coerce(middleware6), coerce(middleware7), coerce(middleware8))
  },
}

function coerce<A>(any: any): A {
  return any
}