Add express-to-koa definition (#23153)

* Add express-to-koa definition

* Fix types

types/express-to-koa/express-to-koa-tests.ts

@@ -0,0 +1,12 @@
+import * as Koa from 'koa';
+import * as connect from 'connect';
+import expressToKoa = require('express-to-koa');
+
+const app = new Koa();
+const middleware: connect.NextHandleFunction = (req, res, next) => {
+    // 'express middleware'
+    next();
+};
+
+app.use(expressToKoa(middleware));
+app.listen(3000);

types/express-to-koa/index.d.ts

@@ -0,0 +1,18 @@
+// Type definitions for express-to-koa 1.0
+// Project: https://github.com/kaelzhang/express-to-koa
+// Definitions by: Xiaohan Zhang <https://github.com/xiaohanzhang>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+import * as Koa from "koa";
+import { IncomingMessage, ServerResponse } from "http";
+
+export = expressToKoa;
+
+declare function expressToKoa(
+    middleware: (
+        req: IncomingMessage,
+        res: ServerResponse,
+        next: (err?: any) => void,
+    ) => void
+): Koa.Middleware;

types/express-to-koa/tsconfig.json

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

types/express-to-koa/tslint.json

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