Question

How do I load a regular NodeJS module (from node_modules) from within a TypeScript class?

When I try to compile .ts file that contains:

var sampleModule = require('modulename');

Compiler prompts that I can’t use require in this scope. (That line is at the beginning of the file).

Answer 1

Typescript will always complain when it is unable to find a symbol. The compiler comes together with a set of default definitions for window, document and such specified in a file called lib.d.ts. If I do a grep for require in this file I can find no definition of a function require. Hence, we have to tell the compiler ourselves that this function will exist at runtime using the declare syntax:

declare function require(name:string);
var sampleModule = require('modulename');

On my system, this compiles just fine.