export function check()

in packages/jest-cli/src/cli/args.ts [11:91]
74 lines of code
17 McCabe index (conditional complexity)

export function check(argv: Config.Argv): true {
  if (
    argv.runInBand &&
    Object.prototype.hasOwnProperty.call(argv, 'maxWorkers')
  ) {
    throw new Error(
      'Both --runInBand and --maxWorkers were specified, but these two ' +
        'options do not make sense together. Which is it?',
    );
  }

  for (const key of [
    'onlyChanged',
    'lastCommit',
    'changedFilesWithAncestor',
    'changedSince',
  ]) {
    if (argv[key] && argv.watchAll) {
      throw new Error(
        `Both --${key} and --watchAll were specified, but these two ` +
          'options do not make sense 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, but these two ' +
        'options do not make sense together.',
    );
  }

  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' +
        'Example usage: jest --maxWorkers 2\n' +
        'Example usage: jest --maxWorkers 50%\n' +
        'Or did you mean --watch?',
    );
  }

  if (argv.selectProjects && argv.selectProjects.length === 0) {
    throw new Error(
      'The --selectProjects option requires the name of at least one project to be specified.\n' +
        'Example usage: jest --selectProjects my-first-project my-second-project',
    );
  }

  if (
    argv.config &&
    !isJSONString(argv.config) &&
    !argv.config.match(
      new RegExp(
        `\\.(${constants.JEST_CONFIG_EXT_ORDER.map(e => e.substring(1)).join(
          '|',
        )})$`,
        'i',
      ),
    )
  ) {
    throw new Error(
      `The --config option requires a JSON string literal, or a file path with one of these extensions: ${constants.JEST_CONFIG_EXT_ORDER.join(
        ', ',
      )}.\nExample usage: jest --config ./jest.config.js`,
    );
  }

  return true;
}