Feathers.js Express: Correct typings for app.use with both middleware and feathers service. (#34782)

* Correct typings for app.use with both middleware and feathers service.

* Correct typings for app.use with both middleware and feathers service.

types/feathersjs__express/feathersjs__express-tests.ts

@@ -3,9 +3,23 @@ import feathersExpress, * as express from '@feathersjs/express';
 
 const app = feathersExpress(feathers());
 
+const feathersServiceDummy   = {
+    get  : () => {
+        return Promise.resolve({});
+    },
+    find : () => {
+        return Promise.resolve([{}, {}]);
+    }
+};
+const expressMiddlewareDummy = (req: express.Request, res: express.Response, next: express.NextFunction) => {
+    next();
+    return app;
+};
+
 app.use(express.json());
-app.use(express.urlencoded({ extended: true }));
+app.use(express.urlencoded({extended : true}));
 app.use('/', express.static('./public'));
+app.use('/', expressMiddlewareDummy, feathersServiceDummy);
 app.configure(express.rest());
 app.use(express.notFound());
-app.use(express.errorHandler({ logger: console }));
+app.use(express.errorHandler({logger : console}));

types/feathersjs__express/index.d.ts

@@ -3,15 +3,31 @@
 // Definitions by: Jan Lohage <https://github.com/j2L4e>
 //                 Aleksey Klimenko <https://github.com/DadUndead>
 // Definitions: https://github.com/feathersjs-ecosystem/feathers-typescript
-// TypeScript Version: 2.3
+// TypeScript Version: 2.8
 
-import { Application as FeathersApplication } from '@feathersjs/feathers';
+import { Application as FeathersApplication, ServiceMethods, SetupMethod } from '@feathersjs/feathers';
 import * as express from 'express';
 import * as self from '@feathersjs/express';
+import { IRouterHandler, PathParams, RequestHandler, RequestHandlerParams } from 'express-serve-static-core';
 
 declare const feathersExpress: (<T>(app: FeathersApplication<T>) => Application<T>) & typeof self;
 export default feathersExpress;
-export type Application<T> = express.Application & FeathersApplication<T>;
+
+type Omit<T, K> = Pick<T, Exclude<keyof T, K>>;
+// TypeScript methods cannot be overloaded with a different signature. Derive two application types without the use methods.
+type ExpressAndFeathersApplicationWithoutUse<T> = Omit<express.Application, 'use'> & Omit<FeathersApplication<T>, 'use'>;
+// Give the "any" type for the feathers options object a more precise name.
+export type FeathersServiceOptions = any;
+
+export interface FeathersRouterMatcher<T> {
+    (path: PathParams, ...handlers: Array<(RequestHandler | RequestHandlerParams | Partial<ServiceMethods<any> & SetupMethod> | Application)>): T;
+}
+
+type FeathersApplicationRequestHandler<T> = express.IRouterHandler<T> & FeathersRouterMatcher<T> & ((...handlers: RequestHandlerParams[]) => T);
+
+export interface Application<T = any> extends ExpressAndFeathersApplicationWithoutUse<T> {
+    use: FeathersApplicationRequestHandler<T>;
+}
 
 export function errorHandler(options?: {
     public?: string,
@@ -19,6 +35,7 @@ export function errorHandler(options?: {
     html?: any,
     json?: any,
 }): express.ErrorRequestHandler;
+
 export function notFound(): express.RequestHandler;
 
 export const rest: {