Options

Introduction

caution

If you are using custom transform config, please remove preset from your Jest config to avoid issues that Jest doesn't transform files correctly.

All ts-jest specific options can be defined in Jest transform config object in the package.json file of your project, or through a jest.config.js, or jest.config.ts file.

JavaScript

// jest.config.js
/** @type {import('ts-jest').JestConfigWithTsJest} */
module.exports = {
  // [...]
  transform: {
    // '^.+\\.[tj]sx?$' to process ts,js,tsx,jsx with `ts-jest`
    // '^.+\\.m?[tj]sx?$' to process ts,js,tsx,jsx,mts,mjs,mtsx,mjsx with `ts-jest`
    '^.+\\.tsx?$': [
      'ts-jest',
      {
        // ts-jest configuration goes here
      },
    ],
  },
}

TypeScript

// jest.config.ts
import type { JestConfigWithTsJest } from 'ts-jest'

const jestConfig: JestConfigWithTsJest = {
  // [...]
  transform: {
    // '^.+\\.[tj]sx?$' to process ts,js,tsx,jsx with `ts-jest`
    // '^.+\\.m?[tj]sx?$' to process ts,js,tsx,jsx,mts,mjs,mtsx,mjsx with `ts-jest`
    '^.+\\.tsx?$': [
      'ts-jest',
      {
        // ts-jest configuration goes here
      },
    ],
  },
}

JSON

// package.json
{
  // [...]
  "jest": {
    "transform": {
      // '^.+\\.[tj]sx?$' to process ts,js,tsx,jsx with `ts-jest`
      // '^.+\\.m?[tj]sx?$' to process ts,js,tsx,jsx,mts,mjs,mtsx,mjsx with `ts-jest`
      "^.+\\.tsx?$": [
        "ts-jest",
        {
          // ts-jest configuration goes here
        }
      ]
    }
  }
}

important

When using TypeScript Jest config file, Jest will use ts-node to compile the config file. ts-jest doesn't take part in that process.

Options

All options have default values which should fit most of the projects. Click on the option's name to see details and example(s).

Option	Description	Type	Default
compiler	TypeScript module to use as compiler.	string	"typescript"
tsconfig	TypeScript compiler related configuration.	string|object|boolean	auto
isolatedModules	Disable type-checking	boolean	disabled
astTransformers	Custom TypeScript AST transformers	object	auto
diagnostics	Diagnostics related configuration.	boolean|object	enabled
babelConfig	Babel(Jest) related configuration.	boolean|string|object	disabled
stringifyContentPathRegex	Files which will become modules returning self content.	string|RegExp	disabled
useESM	Enable ESM support	boolean	auto