External Types

Unless you’re teaching TypeScript/JavaScript, you’re probably going to want to import libraries into your code samples.

Twoslash works by faking a virtual file system over your existing file system. This means any @types or libraries with TypeScript definitions should work out of the box with no config.

Globals

Setting up globals is a little bit more complex, but not drastically. You need to use the triple slash reference which adds a particular library to the global scope.

Output

import { writeFileSync } from "node:fs";
writeFileSync("myfile.txt", "// TODO");

Markdown

```ts twoslash
/// <reference types="node" />
// ---cut---
import { writeFileSync } from "node:fs";
writeFileSync("myfile.txt", "// TODO");
```