jest-ts

library1.1.22jsnpmunverified

jest-ts is a high-performance Jest TypeScript transpiler powered by esbuild, offering 5-10x faster transpilation than ts-jest. Version 1.1.22 is the latest stable with a monthly release cadence. Key differentiators include intelligent caching based on code content, config, and package versions; on-demand type checking using the official TypeScript API that does not block test execution; and a one-click init command (npx jest-ts init) that generates config files, example code, and npm scripts. Supports Node.js and browser (jsdom) environments, and both CommonJS and ES modules. Requires jest >= 28.0.0 and TypeScript >= 5.0.0.

testing

npm install jest-ts

package ↗homepage ↗

INSTALL

IMPORT

SIG · JEST-TS

jest-ts

testingjavascriptv1.1.22

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

jest-ts/jest-preset

✓ preset: 'jest-ts/jest-preset' // in jest.config.js

✗ preset: 'jest-ts' // Missing /jest-preset path

The preset must be referenced as 'jest-ts/jest-preset', not just 'jest-ts'.

globals['jest-ts']

✓ globals: { 'jest-ts': { typeCheck: true } } // in jest.config.js

✗ globals: { jest-ts: { typeCheck: true } } // Without quotes, Jest may interpret as object key

In JavaScript config, the key must be a string literal 'jest-ts' to avoid interpretation as a nested object.

init command

✓ npx jest-ts init

✗ npm init jest-ts // Incorrect command

Use npx jest-ts init to run the initialization CLI tool.

Install jest-ts, run one-click init to generate config and example test, then run tests.

npm install jest-ts jest typescript --save-dev npx jest-ts init # Respond to prompts (e.g., overwrite files) npm install npm test # Expected output: Test Suites: 1 passed, 1 total

jest-ts --version

Debug

Known issues

breakingjest-ts requires jest >= 28.0.0 and typescript >= 5.0.0. Using older versions will cause errors.

fix

Upgrade jest to v28+ and TypeScript to v5+.

affects: >=1.0.0

breakingNode.js version must be >=16.0.0 due to esbuild dependency.

fix

Use Node.js 16+ (currently LTS).

affects: >=1.0.0

deprecatedThe 'jest-ts' preset path is 'jest-ts/jest-preset', not a simple 'jest-ts'.

fix

Use preset: 'jest-ts/jest-preset' in Jest config.

affects: >=1.0.0

gotchaThe globals key must be quoted: 'jest-ts' (string).

fix

Write globals: { 'jest-ts': { ... } } in JavaScript config.

affects: >=1.0.0

Errors

Common errors & fixes

Cannot find module 'jest-ts/jest-preset' from 'jest.config.js'

Preset path is incorrect or jest-ts not installed.

fix

Ensure jest-ts is installed: npm install jest-ts --save-dev. Verify preset: 'jest-ts/jest-preset'.

Error: Jest: 'jest-ts' preset not found. Did you mean to use 'jest-ts/jest-preset'?

Using preset: 'jest-ts' instead of 'jest-ts/jest-preset'.

fix

Change preset to 'jest-ts/jest-preset'.

TypeError: jest_ts_1.default is not a function

Incorrect import or CommonJS/ESM mismatch when using jest-ts transformer directly.

fix

Do not import jest-ts directly; use the preset in Jest config.

Upgrade

Version history

1.1.22latest on npm

Audit

Dependencies

jestrequiredCore peer dependency; jest-ts is a Jest transformer and preset.

typescriptrequiredRequired for type checking and TypeScript compilation; peer dependency.

esbuildrequiredUnderlying transpiler used for fast TypeScript to JavaScript conversion.

Agent activity

2 hits · last 30 days

node

Resources

packagehttps://www.npmjs.com/package/jest-ts ↗

homepagehttps://hub.js.cn ↗