How to reference externally defined node modules with string identifiers with typescript - node.js

Question

I'm writing a set of node helper modules in typescript. I'm having difficulty getting typescript to interpret type information for external node modules such as "fs" and "path".
Importantly, I want to separate my module into a bunch of Typescript files, with a class/interface per file. They file layout is like this:
ts/ISomeInterface1.ts
ts/ISomeInterface2.ts
ts/SomeClass1.ts
ts/SomeClass2.ts
A class instantiates one or more interfaces, and is written as follows:
///<reference path="IFileSystemHelpers.ts" />
var fs = require("fs");
namespace myNmspace {
export class SomeClass1 implements SomeInterface1 {
public someIFunction() {
//do work
}
}
}
I'm using gulp-typescript to install type declarations for NodeJs. And I use a tsconfig.json file to build and reference these external typings. Here's a snippet:
{
"version": "1.8.9",
"compilerOptions": {
"target": "es6",
"module": "commonjs",
"moduleResolution": "node",
"sourceMap": true,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"noImplicitAny": false,
"removeComments": true,
"noLib": false,
"preserveConstEnums": true,
"declaration": true,
"suppressImplicitAnyIndexErrors": true,
"out": "./outputfile.js"
},
"filesGlob": [
"./**/*.ts",
"!./node_modules/**/*.ts"
],
"files": [
"./typings/main.d.ts",
"./ts/ISomeInterface1.ts",
"./ts/ISomeInterface2.ts",
"./ts/SomeClass1.ts",
"./ts/SomeClass2.ts",
"./ts/exports.ts"
]
}
Then classes are exported in the exports.ts file:
declare var exports: any;
if (exports) {
exports.SomeClass1 = myNmspace.SomeClass1;
exports.SomeClass2 = myNmspace.SomeClass2;
}
Then comes my problem. How do I get type information for the "fs" module?
I can see the following in the node.d.ts file (see here)that typings has installed:
declare module "fs" {
import * as stream from "stream";
import * as events from "events";
...
}
How do I force Typescript to interpret my fs variable in the SomeClass1.ts file as strongly-typed? In other words, what do I write here:
var fs : ??? = require("fs");
Can anyone help?
As an aside, I've noticed that if I replace the var with an import keyword, I get correct type interpretation for the fs variable. However the terms which point to my interfaces break and I get a squiggly line under the implements ISomeInterface1. Changing the pattern to use imports breaks my file separation, and seems valid only if I want to create a single-file node module.

Answer 1

Use ES6 style imports
import * as fs from 'fs'
import * as path from 'path'
This will also import the definitions from the definition file.
The syntax var x = require('x') does not (however import x = require('x') does, to add to the confusion)