jestjs/jest · error · Error

Both --onlyFailures and --watchAll were specified, only one…

Error message

Both --onlyFailures and --watchAll were specified, only one is allowed.

What it means

check() separately rejects --onlyFailures together with --watchAll (args.ts:37-41) because --onlyFailures relies on a static snapshot of the previous run's results, while --watchAll continuously reruns everything. The two modes operate on incompatible notions of which tests to select.

Solutions

Drop --watchAll if you want to keep rerunning only previously-failed tests.
Switch to plain --watch (reruns tests related to changed files) instead of --watchAll if you want live feedback.
If you want both behaviors, run them as separate jest invocations.

Example fix

// before
jest --onlyFailures --watchAll
// after
jest --onlyFailures

Defensive patterns

Strategy: validation

Validate before calling

function validateFlags(argv: { onlyFailures?: boolean; watchAll?: boolean }): void {
  if (argv.onlyFailures && argv.watchAll) {
    throw new Error('--onlyFailures and --watchAll are mutually exclusive');
  }
}

Prevention

Keep --onlyFailures for one-shot reruns; use --watch (not --watchAll) for live feedback.
Build a small CLI-flag wrapper that rejects known-incompatible pairs.

When it happens

Trigger: Running jest --onlyFailures --watchAll; jest -f --watchAll; combining a flaky-test rerun workflow with watch-all development.

Common situations: Adding --watchAll to a script that already uses --onlyFailures to chase down failing tests; aliasing watch to watchAll by mistake.

Related errors

AI-assisted analysis of jestjs/jest@8e6d128e4a (2026-08-10). Data as JSON: /api/errors/48155784e9d35da1. Report an issue: GitHub.

Appendix: source

Thrown at packages/jest-cli/src/args.ts:38

  }

  for (const key of [
    'onlyChanged',
    'lastCommit',
    'changedFilesWithAncestor',
    'changedSince',
  ]) {
    if (argv[key] && argv.watchAll) {
      throw new Error(
        `Both --${key} and --watchAll were specified, but cannot be used ` +
          'together. Try the --watch option which reruns only tests ' +
          'related to changed files.',
      );
    }
  }

  if (argv.onlyFailures && argv.watchAll) {
    throw new Error(
      'Both --onlyFailures and --watchAll were specified, only one is allowed.',
    );
  }

  if (argv.findRelatedTests && argv._.length === 0) {
    throw new Error(
      'The --findRelatedTests option requires file paths to be specified.\n' +
        'Example usage: jest --findRelatedTests ./src/source.js ' +
        './src/index.js.',
    );
  }

  if (
    Object.prototype.hasOwnProperty.call(argv, 'maxWorkers') &&
    argv.maxWorkers === undefined
  ) {
    throw new Error(
      'The --maxWorkers (-w) option requires a number or string to be specified.\n' +

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