jiti

Runtime Typescript and ESM support for Node.js

[!IMPORTANT] This is the development branch for jiti v2. Check out jiti/v1 for latest stable docs and unjs/jiti#174 for the v2 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

License

MIT. Made with 💖