Specifying type of function parameters with TypeScript

Question

I'm trying to specify a function parameter type in a Node app. This is what I came up with:

import express = require("express");

module.exports = (app) => {
    app.get('/', (req: express.Request, res: express.Response) => { // <- this fails to compile
        // do work
    });
}

and it generates this JS, which is not quite right, apparently:

define(["require", "exports"], function(require, exports) {
    module.exports = function (app) {
      //......
    };
});

TS definitions are coming from DefinitelyTyped. "express" is defined as

declare module "express" {

in a .d.ts file.

Obviously i'm doing it wrong.. Any hints?

EDIT: To expand on basarat's answer: In csproj file find TypeScriptModuleKind entry, and set it to COMMONJS.

The ts ended up looking like this:

import express = require("express");

module.exports = (app: express.Application) => {
    app.get("/", (req, res) => {
        res.send({ name: "woohooo" });
    });
}

basarat · Accepted Answer · 2014-01-09 04:01:14Z

1

The javascript generated looks like :

define(["require", "exports"], function(require, exports) {
    module.exports = function (app) {
      //......
    };
});

because you are compiling with --module amd. For node you should use --module commonjs see : http://www.youtube.com/watch?v=KDrWLMUY0R0&hd=1

PS: you need to reference the express type definitions for TypeScript to know about express usage : https://github.com/borisyankov/DefinitelyTyped/blob/master/express/express-tests.ts#L77 The definition : https://github.com/borisyankov/DefinitelyTyped/blob/master/express/express.d.ts

answered Jan 9, 2014 at 4:01

basarat

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