Product
Introducing Java Support in Socket
We're excited to announce that Socket now supports the Java programming language.
The jiti npm package is a runtime TypeScript and ES Module (ESM) loader that allows you to import TypeScript files, ESM, or JSON modules dynamically in a Node.js environment without the need for prior compilation. It is designed to be a zero-config, drop-in replacement for dynamic imports and require calls, providing just-in-time transpilation of code.
Dynamic Import of TypeScript Files
This feature allows you to dynamically import TypeScript files at runtime. The jiti function is called with the current filename to create a context, and then it is used to import a TypeScript module, which is transpiled just-in-time.
const jiti = require('jiti')(__filename)
const myModule = jiti('./my-module.ts')
Dynamic Import of ESM
With this feature, jiti can dynamically import ES Module files. The 'esmResolve' option enables proper resolution of ESM modules, allowing them to be loaded at runtime without prior compilation.
const jiti = require('jiti')(__filename, { esmResolve: true })
const myESMModule = jiti('./my-esm-module.mjs')
Dynamic Import of JSON Modules
This feature enables the dynamic import of JSON modules. By using jiti, you can load JSON files at runtime, which can be useful for configuration files or other data that needs to be imported into your application.
const jiti = require('jiti')(__filename)
const config = jiti('./config.json')
esbuild-register is a package that uses the esbuild bundler to transpile TypeScript and modern JavaScript on the fly for Node.js. It is similar to jiti in that it allows just-in-time transpilation, but it leverages the fast esbuild compiler.
ts-node is a TypeScript execution engine and REPL for Node.js. It provides on-the-fly transpilation of TypeScript into JavaScript, allowing developers to execute TypeScript directly without pre-compilation. ts-node is widely used and has more configuration options compared to jiti.
babel-register is a Babel hook that transpiles files on the fly when they are required. It is similar to jiti in providing just-in-time transpilation, but it uses Babel, which has a wide range of plugins and is highly configurable.
This is the active development branch. Check out jiti/v1 for legacy v1 docs and code.
Docusaurus, ESLint, FormKit, Histoire, Knip, Nitro, Nuxt, PostCSS loader, Rsbuild, Size Limit, Slidev, Tailwindcss, Tokenami, UnoCSS, WXT, Winglang, Graphql code generator, Lingui, Scaffdog, Storybook, ...UnJS ecosystem, ...60M+ npm monthly downloads, ...6M+ public repositories.
import()
require()
(deprecated)require.cache
integration[!IMPORTANT] To enhance compatibility, jiti
>=2.1
enabledinteropdefault
using a new Proxy method. If you migrated to2.0.0
earlier, this might have caused behavior changes. In case of any issues during the upgrade, please report so we can investigate to solve them. 🙏🏼
You can use jiti
CLI to quickly run any script with TypeScript and native ESM support!
npx jiti ./index.ts
Initialize a jiti instance:
// ESM
import { createJiti } from "jiti";
const jiti = createJiti(import.meta.url);
// CommonJS (deprecated)
const { createJiti } = require("jiti");
const jiti = createJiti(__filename);
Import (async) and resolve with ESM compatibility:
// jiti.import(id) is similar to import(id)
const mod = await jiti.import("./path/to/file.ts");
// jiti.esmResolve(id) is similar to import.meta.resolve(id)
const resolvedPath = jiti.esmResolve("./src");
If you need the default export of module, you can use jiti.import(id, { default: true })
as shortcut to mod?.default ?? mod
.
// shortcut to mod?.default ?? mod
const modDefault = await jiti.import("./path/to/file.ts", { default: true });
CommonJS (sync & deprecated):
// jiti() is similar to require(id)
const mod = jiti("./path/to/file.ts");
// jiti.resolve() is similar to require.resolve(id)
const resolvedPath = jiti.resolve("./src");
You can also pass options as the second argument:
const jiti = createJiti(import.meta.url, { debug: true });
You can globally register jiti using global hooks. (Important: Requires Node.js > 20)
import "jiti/register";
Or:
node --import jiti/register index.ts
jiti/native
You can alias jiti
to jiti/native
to directly depend on runtime's import.meta.resolve
and dynamic import()
support. This allows easing up the ecosystem transition to runtime native support by giving the same API of jiti.
debug
false
JITI_DEBUG
Enable verbose logging. You can use JITI_DEBUG=1 <your command>
to enable it.
fsCache
true
JITI_FS_CACHE
Filesystem source cache (enabled by default)
By default (when is true
), jiti uses node_modules/.cache/jiti
(if exists) or {TMP_DIR}/jiti
.
Note: It is recommended that this option be enabled for better performance.
moduleCache
true
JITI_MODULE_CACHE
Runtime module cache (enabled by default).
Disabling allows editing code and importing the same module multiple times.
When enabled, jiti integrates with Node.js native CommonJS cache-store.
transform
Transform function. See src/babel for more details
sourceMaps
false
JITI_SOURCE_MAPS
Add inline source map to transformed source for better debugging.
interopDefault
true
JITI_INTEROP_DEFAULT
Jiti combines module exports with the default
export using an internal Proxy to improve compatibility with mixed CJS/ESM usage. You can check the current implementation here.
alias
JITI_ALIAS
You can also pass an object to the environment variable for inline config. Example: JITI_ALIAS='{"~/*": "./src/*"}' jiti ...
.
Custom alias map used to resolve IDs.
nativeModules
JITI_NATIVE_MODULES
List of modules (within node_modules
) to always use native require()
for them.
transformModules
JITI_TRANSFORM_MODULES
List of modules (within node_modules
) to transform them regardless of syntax.
importMeta
Parent module's import.meta
context to use for ESM resolution. (only used for jiti/native
import).
tryNative
JITI_TRY_NATIVE
Try to use native require and import without jiti transformations first.
jsx
false
JITI_JSX
Enable JSX support using @babel/plugin-transform-react-jsx
.
See test/fixtures/jsx
for framework integration examples.
corepack enable
pnpm install
pnpm dev
pnpm jiti ./test/path/to/file.ts
Published under the MIT license.
Made by @pi0 and community 💛
FAQs
Runtime typescript and ESM support for Node.js
The npm package jiti receives a total of 16,139,197 weekly downloads. As such, jiti popularity was classified as popular.
We found that jiti demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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Product
We're excited to announce that Socket now supports the Java programming language.
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