esbuild-jest-fixed

0.5.2 verified Fri May 01 auth: no javascript

A Jest transformer leveraging esbuild for fast TypeScript, JavaScript, TSX, and JSX compilation. Version 0.5.2 is the latest stable release; the project is a fork of esbuild-jest that resolves a critical bug where source code containing the substring "ock(" (e.g., "mock(") would cause compilation failures. It supports configurable jsxFactory, jsxFragment, sourcemap, loaders, target, and format options, and is designed as a drop-in replacement for ts-jest with significantly faster transpilation. Requires esbuild >=0.9.3 as a peer dependency. The package ships TypeScript type definitions.

Common errors

error Cannot find module 'esbuild-jest' from 'jest.config.js' ↓

cause Using 'esbuild-jest' in Jest config but package not installed or intended to use fork

fix

Install esbuild-jest-fixed and use 'esbuild-jest-fixed' in config

error TypeError: createTransformer is not a function ↓

cause Importing named export `createTransformer` instead of default import

fix

Use import createTransformer from 'esbuild-jest-fixed' (no braces)

error Module build failed: Error: The package "esbuild" is required but not installed ↓

cause Missing peer dependency esbuild

fix

Run npm install esbuild --save-dev

Warnings

breaking Jest transform keys using 'esbuild-jest' will not work with the fixed fork; must use 'esbuild-jest-fixed' ↓

fix Replace 'esbuild-jest' with 'esbuild-jest-fixed' in Jest configuration transform patterns

gotcha Source code containing substring 'ock(' (e.g., 'mock(' or 'block(') could cause compilation errors in original esbuild-jest <0.2.0; fixed fork resolves this ↓

fix Use esbuild-jest-fixed v0.5.2+ which patches the 'ock(' issue

deprecated The original esbuild-jest package is no longer maintained; this fork is the active alternative ↓

fix Migrate to esbuild-jest-fixed for continued support and bug fixes

Install

npm install esbuild-jest-fixed

yarn add esbuild-jest-fixed

pnpm add esbuild-jest-fixed

Imports

esbuild-jest-fixed
wrong
```
import { createTransformer } from 'esbuild-jest-fixed'
```
correct
```
import createTransformer from 'esbuild-jest-fixed'
```
Package exports a default transformer factory; named export does not exist in v0.5.2

Options (type)

wrong

import { Options } from 'esbuild-jest-fixed'  // Options is a type, not a runtime value

correct

import type { Options } from 'esbuild-jest-fixed'

TypeScript type import only; using value import will fail at runtime

Jest config string reference
wrong
```
"esbuild-jest" in config when using the fork
```
correct
```
"esbuild-jest-fixed" in Jest transform config
```
Package name in Jest config must exactly match 'esbuild-jest-fixed' to find the correct module

Quickstart

Configures Jest with esbuild-jest-fixed transformer to compile TypeScript files, demonstrates a basic test and implementation.

// jest.config.js
module.exports = {
  transform: {
    '^.+\\.tsx?$': [
      'esbuild-jest-fixed',
      {
        sourcemap: true,
        target: 'es2020'
      }
    ]
  }
};

// example.test.ts
import { sum } from './sum';

test('sum adds numbers', () => {
  expect(sum(1, 2)).toBe(3);
});

// sum.ts
export function sum(a: number, b: number): number {
  return a + b;
}

// Run: npx jest