const lockVerify = require('lock-verify')
lockVerify(moduleDir).then(result => {
  result.warnings.forEach(w => console.error('Warning:', w))
  if (!result.status) {
    result.errors.forEach(e => console.error(e))
    process.exit(1)
  }
})

As a library it's a function that takes the path to a module and returns a promise that resolves to an object with .status, .warnings and .errors properties. The first will be true if everything was ok (though warnings may exist). If there's no package.json or no lockfile in moduleDir or they're unreadable then the promise will be rejected.