Is ts-node needed to run Jest in Next.js 14 with TypeScript

Question

I'm following the manual setup as described here to configure Jest in Next.js 14.1.3 with TypeScript.

When run jest, it complaints that 'ts-node' is required:

Error: Jest: Failed to parse the TypeScript config file C:\Users\dummy\playground\jest.config.ts
  Error: Jest: 'ts-node' is required for the TypeScript configuration files. Make sure it is installed
Error: Cannot find package 'ts-node' imported from C:\Users\dummy\playground\node_modules\jest-config\build\readConfigFileAndSetRootDir.js

However, the installation step did mention ts-node

npm install -D jest jest-environment-jsdom @testing-library/react @testing-library/jest-dom

Is this a documentation error or I'm missing something here?

Answer 1

I had the same issue and found that the issue was because the configuration was saved as .ts. So what I did to fix the issue was to rename the configuration file to jest.config.js and change the content like below:

/**
 * For a detailed explanation regarding each configuration property, visit:
 * https://jestjs.io/docs/configuration
 */


const nextJest = require('next/jest')

const createJestConfig = nextJest({
  // Provide the path to your Next.js app to load next.config.js and .env files in your test environment
  dir: './',
})

/** @type {import('jest').Config} */
const config = {
 // Indicates whether the coverage information should be collected while executing the test
  collectCoverage: true,

  // An array of glob patterns indicating a set of files for which coverage information should be collected
  // collectCoverageFrom: undefined,

  // The directory where Jest should output its coverage files
  coverageDirectory: "coverage",

  // Indicates which provider should be used to instrument code for coverage
  coverageProvider: "v8",


  // The test environment that will be used for testing
  testEnvironment: "jsdom",
};

module.exports = createJestConfig(config);