Lazy require with support for TypeScript

Require node modules lazily. This improves start-up times, because this work is simply delayed. Modules are only loaded synchronously when needed.

Installation

npm i lazy-require-ts

Usage

A prefix must be added to source files after they have been compiled with TypeScript. This can be done either on the fly, or in a build step.

import { makePrefixCode } from "lazy-require-ts";

const prefix = makePrefixCode();

const source = "...";

const sourceWithLazyLoad = prefix + source;

TypeScript must be configured to emit commonjs modules.

Known issues

• There is no viable way to support ES modules.
  • There's no way to construct ES modules synchronously, when fx functions are called.
  • There's no API hook, that allows modification of module exports. To avoid exporting unreachable code.
  • Possible workaround: Transpile ES modules and load them as CommonJS modules. But that's beyond the scope of this package.

Related work

• import-lazy
• lazy-require

License

MIT