jiti

Runtime Typescript and ESM support for Node.js.

[!IMPORTANT] This is the support branch for jiti v1. Check out jiti/main for the latest version and unjs/jiti#174 for the roadmap.

Features

Seamless typescript and ESM syntax support
Seamless interoperability between ESM and CommonJS
Synchronous API to replace require
Super slim and zero dependency
Smart syntax detection to avoid extra transforms
CommonJS cache integration
Filesystem transpile hard cache
V8 compile cache
Custom resolve alias

Usage

Programmatic

const jiti = require("jiti")(__filename);

jiti("./path/to/file.ts");

You can also pass options as second argument:

const jiti = require("jiti")(__filename, { debug: true });

CLI

jiti index.ts
# or npx jiti index.ts

Register require hook

node -r jiti/register index.ts

Alternatively, you can register jiti as a require hook programmatically:

const jiti = require("jiti")();
const unregister = jiti.register();

Options

`debug`

Type: Boolean
Default: false
Environment Variable: JITI_DEBUG

Enable debug to see which files are transpiled

`cache`

Type: Boolean | String
Default: true
Environment Variable: JITI_CACHE

Use transpile cache

If set to true will use node_modules/.cache/jiti (if exists) or {TMP_DIR}/node-jiti

`esmResolve`

Type: Boolean | String
Default: false
Environment Variable: JITI_ESM_RESOLVE

Using esm resolution algorithm to support import condition.

`transform`

Type: Function
Default: Babel (lazy loaded)

Transform function. See src/babel for more details

`sourceMaps`

Type: Boolean
Default false
Environment Variable: JITI_SOURCE_MAPS

Add inline source map to transformed source for better debugging.

`interopDefault`

Type: Boolean
Default: false

Return the .default export of a module at the top-level.

`alias`

Type: Object
Default: -
Environment Variable: JITI_ALIAS

Custom alias map used to resolve ids.

`nativeModules`

Type: Array
Default: ['typescript`]
Environment Variable: JITI_NATIVE_MODULES

List of modules (within node_modules) to always use native require for them.

`transformModules`

Type: Array
Default: []
Environment Variable: JITI_TRANSFORM_MODULES

List of modules (within node_modules) to transform them regardless of syntax.

`experimentalBun`

Type: Boolean
Default: Enabled if process.versions.bun exists (Bun runtime)
Environment Variable: JITI_EXPERIMENTAL_BUN

Enable experimental native Bun support for transformations.

Development

Clone this repository
Enable Corepack using corepack enable
Install dependencies using pnpm install
Run pnpm dev
Run pnpm jiti ./test/path/to/file.ts