Add typings for express-ws (#24984)

* Add types for express-ws

* strictFunctionTypes=true

* dtslint compliant

* union types for application and router

* allow https server

* applyTo accepts object

* fix lint error

* applyTo accepts router-like obj

* websocket method returns this

types/express-ws/express-ws-tests.ts

@@ -0,0 +1,72 @@
+import http = require('http');
+import https = require('https');
+import express = require('express');
+import expressWs = require('express-ws');
+
+const dummyApp = express();
+const httpServer = http.createServer(dummyApp);
+const httpsServer = https.createServer({}, dummyApp);
+
+expressWs(dummyApp); // optional server argument
+expressWs(dummyApp, httpsServer); // https server allowed
+expressWs(dummyApp, httpServer, {
+    leaveRouterUntouched: false,
+    // ws server options
+    wsOptions: {
+        clientTracking: true
+    }
+});
+
+const { app, getWss, applyTo } = expressWs(express());
+
+/**
+ * applyTo accepts router object
+ */
+applyTo(express.Router());
+
+/**
+ * applyTo accepts router-like objects
+ */
+applyTo({
+    get() { return this; }
+});
+
+/**
+ * getWss function returns ws server
+ */
+getWss().clients.forEach(ws => {
+    if (ws.readyState !== ws.OPEN) {
+        ws.terminate();
+        return;
+    }
+    ws.ping();
+});
+
+/**
+ * ws method is added to express app instance
+ */
+app.ws('/', (ws, req) => {
+    ws.on('message', msg => {
+        console.log(msg);
+    });
+});
+
+/**
+ * ws method is added to express.Router prototype
+ */
+const router = express.Router();
+
+router.ws(
+    '/:id',
+    (ws, req, next) => { next(); },
+    (ws, req, next) => {
+        ws.send(req.params.id);
+
+        ws.on('close', (code, reason) => {
+            console.log('code:', code);
+            console.log('reason:', reason);
+        });
+    }
+);
+
+app.use(router);

types/express-ws/index.d.ts

@@ -0,0 +1,47 @@
+// Type definitions for express-ws 3.0
+// Project: https://github.com/HenningM/express-ws
+// Definitions by: AJ Livingston <https://github.com/ajliv>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+import * as core from 'express-serve-static-core';
+import * as express from 'express';
+import * as http from 'http';
+import * as https from 'https';
+import * as ws from 'ws';
+
+declare module 'express' {
+    function Router(options?: RouterOptions): expressWs.Router;
+}
+
+declare function expressWs(app: express.Application, server?: http.Server | https.Server, options?: expressWs.Options): expressWs.Instance;
+declare namespace expressWs {
+    type Application = express.Application & WithWebsocketMethod;
+    type Router = express.Router & WithWebsocketMethod;
+
+    interface Options {
+        leaveRouterUntouched?: boolean;
+        wsOptions?: ws.ServerOptions;
+    }
+
+    interface RouterLike {
+        get: express.IRouterMatcher<this>;
+        [key: string]: any;
+        [key: number]: any;
+    }
+
+    interface Instance {
+        app: Application;
+        applyTo(target: RouterLike): void;
+        getWss(): ws.Server;
+    }
+
+    type WebsocketRequestHandler = (ws: ws, req: express.Request, next: express.NextFunction) => void;
+    type WebsocketMethod<T> = (route: core.PathParams, ...middlewares: WebsocketRequestHandler[]) => T;
+
+    interface WithWebsocketMethod {
+        ws: WebsocketMethod<this>;
+    }
+}
+
+export = expressWs;

types/express-ws/tsconfig.json

@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "express-ws-tests.ts"
+    ]
+}

types/express-ws/tslint.json

@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }