TypeScript getting error TS2304: cannot find name ' require'

Question

I am trying to get my first TypeScript and DefinitelyTyped Node.js application up and running, and running into some errors.

I am getting the error "TS2304: Cannot find name 'require' " when I attempt to transpile a simple TypeScript Node.js page. I have read through several other occurrences of this error on Stack Overflow, and I do not think I have similar issues. I am running at the shell prompt the command:

tsc movie.server.model.ts.

The contents of this file are:

'use strict';

/// <reference path="typings/tsd.d.ts" />

/*    movie.server.model.ts - definition of movie schema */

var mongoose = require('mongoose'),
Schema = mongoose.Schema;

var foo = 'test';

The error is thrown on the var mongoose=require('mongoose') line.

The contents of the typings/tsd.d.ts file are:

/// <reference path="node/node.d.ts" />
/// <reference path="requirejs/require.d.ts" />

The .d.ts file references were placed in the appropriate folders and added to typings/tsd.d.ts by the commands:

tsd install node --save
tsd install require --save

The produced .js file seems to work fine, so I could ignore the error. But I would appreciate knowing why this error occurs and what I am doing wrong.

Answer 1

Quick and Dirty

If you just have one file using require, or you're doing this for demo purposes you can define require at the top of your TypeScript file.

declare var require: any

TypeScript 2.x

If you are using TypeScript 2.x you no longer need to have Typings or Definitely Typed installed. Simply install the following package.

npm install @types/node --save-dev

The Future of Declaration Files (6/15/2016)

Tools like Typings and tsd will continue to work, and we’ll be working alongside those communities to ensure a smooth transition.

Verify or Edit your src/tsconfig.app.json so that it contains the following:

...
"types": [ "node" ],
"typeRoots": [ "../node_modules/@types" ]
...

Make sure is the file in the src folder and no the one on the root app folder.

By default, any package under @types is already included in your build unless you've specified either of these options. Read more

TypeScript 1.x

Using typings (DefinitelyTyped's replacement) you can specify a definition directly from a GitHub repository.

Install typings

npm install typings -g --save-dev

Install the requireJS type definition from DefinitelyType's repo

typings install dt~node --save --global

Webpack

If you are using Webpack as your build tool you can include the Webpack types.

npm install --save-dev @types/webpack-env

Update your tsconfig.json with the following under compilerOptions:

"types": [
      "webpack-env"
    ]

This allows you to do require.ensure and other Webpack specific functions.

Angular CLI

With CLI you can follow the Webpack step above and add the "types" block to your tsconfig.app.json.

Alternatively, you could use the preinstalled node types. Keep in mind this will include additional types to your client-side code that are not really available.

"compilerOptions": {
    // other options
    "types": [
      "node"
    ]
  }