jestjs/jest · error · NotFoundPackageJsonError

Could not find a "package.json" file in

Error message

Could not find a "package.json" file in ${rootDir}

What it means

create-jest (the engine behind `jest --init` / `npm init jest`) requires a package.json in the target directory because it writes a Jest config alongside it and optionally modifies the `scripts.test` entry. NotFoundPackageJsonError is thrown from runCreate when path.join(rootDir, 'package.json') does not exist on disk. Without a package.json there is nowhere to record the test script and no project root to anchor the generated config.

Solutions

1. Run `npm init -y` (or `yarn init`) in the target directory to create a package.json, then re-run `jest --init`.
2. Verify the path you passed to create-jest / `jest --init` is the intended project root and exists.
3. If you already have a package.json in a parent directory, run the command from that directory instead.

Example fix

// before
$ jest --init
# -> Could not find a "package.json" file in /tmp/foo

// after
$ npm init -y && jest --init

// Before calling runCreate / jest --init, verify package.json exists.
import * as path from 'node:path';
import * as fs from 'node:fs';

function ensurePackageJson(rootDir) {
  const p = path.join(rootDir, 'package.json');
  if (!fs.existsSync(p)) {
    throw new Error(`No package.json in ${rootDir}. Run 'npm init -y' first.`);
  }
  return p;
}

function hasPackageJson(rootDir: string): boolean {
  return fs.existsSync(path.join(rootDir, 'package.json'));
}

When it happens

Trigger: Running `npx create-jest <dir>` or `jest --init` in a directory (or a passed argv path) that has no package.json file. Also triggered when the realpath of the supplied rootDir resolves to a folder that was never `npm init`-ed.

Common situations: Initialising Jest in a scratch/empty folder before running `npm init -y`; passing a wrong path argument to create-jest; running the init from a subdirectory of a fresh clone that has not yet been bootstrapped.

Related errors

• There is malformed json in
• Cannot parse as JSON
• Attempted to display seed but seed value is undefined
• babel-jest: Babel ignores
• Crawler retry failed: Original error

AI-assisted analysis of jestjs/jest@8e6d128e4a (2026-08-10). Data as JSON: /api/errors/0a17f29a723b20f6. Report an issue: GitHub.

Appendix: source

Thrown at packages/create-jest/src/runCreate.ts:56

    clearLine(process.stdout);
    if (error instanceof Error && Boolean(error?.stack)) {
      console.error(chalk.red(error.stack));
    } else {
      console.error(chalk.red(error));
    }

    exit(1);
    throw error;
  }
}

export async function runCreate(rootDir = process.cwd()): Promise<void> {
  rootDir = tryRealpath(rootDir);
  // prerequisite checks
  const projectPackageJsonPath = path.join(rootDir, PACKAGE_JSON);

  if (!fs.existsSync(projectPackageJsonPath)) {
    throw new NotFoundPackageJsonError(rootDir);
  }

  const questions = [...defaultQuestions];
  let hasJestProperty = false;
  let projectPackageJson: ProjectPackageJson;

  try {
    projectPackageJson = JSON.parse(
      fs.readFileSync(projectPackageJsonPath, 'utf8'),
    ) as ProjectPackageJson;
  } catch {
    throw new MalformedPackageJsonError(projectPackageJsonPath);
  }

  if (projectPackageJson.jest) {
    hasJestProperty = true;
  }

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