TypeScript Config option

The tsConfig option allows you to define the which tsconfig JSON file to use. An inline compiler options object can also be specified instead of the path to a file.

By default, it’ll use the default TypeScript and use the project’s tsconfig.json file. If it cannot find one, it’ll use defaults TypeScript compiler options (except es5 is used as target instead of es3).

If you need to use defaults and force ts-jest to use the defaults even if there is a tsconfig.json in your project, you can set this option to false.

Examples

Path to a tsconfig file

The path should be relative to the current working directory where you start Jest from. You can also use <rootDir> in the path to start from the project root dir.

// jest.config.js
module.exports = {
  // [...]
  globals: {
    'ts-jest': {
      tsConfig: 'tsconfig.test.json'
    }
  }
};

// OR package.json
{
  // [...]
  "jest": {
    "globals": {
      "ts-jest": {
        "tsConfig": "tsconfig.test.json"
      }
    }
  }
}

Inline compiler options

Refer to the TypeScript compiler options to know what can be used. It’s basically the same object you’d put in your tsconfig.json’s compilerOptions.

// jest.config.js
module.exports = {
  // [...]
  globals: {
    'ts-jest': {
      tsConfig: {
        importHelpers: true
      }
    }
  }
};

// OR package.json
{
  // [...]
  "jest": {
    "globals": {
      "ts-jest": {
        "tsConfig": {
          "importHelpers": true
        }
      }
    }
  }
}

Disable auto-lookup

By default ts-jest will try to find the tsconfig.json in your project. But you may want to not use it at all and keep TypeScript default options. You can achieve this by setting tsConfig to false.

// jest.config.js
module.exports = {
  // [...]
  globals: {
    'ts-jest': {
      tsConfig: false
    }
  }
};

// OR package.json
{
  // [...]
  "jest": {
    "globals": {
      "ts-jest": {
        "tsConfig": false
      }
    }
  }
}