optional param in schema cause error : Cannot set property 'message' of undefined (v4.1)

[vitaliybilous]

lib : 4.1,
node : 8.1.4,
os : ubuntu 14.04

Use legacy API (schema) for validation.
My code:

export const validatePostPageData = async (req, res, next) => {
  /*
  POST data : { data : { props : "ABC" } }
  */
  req.checkBody({
    'data.props' : {
      optional: true
    }
  });

  const result = await req.getValidationResult();

  if (!result.isEmpty()) {
    res.status(400).send({error: result.array().map(({param, msg}) => ({param, msg}))});
    return;
  }

  next();
};

Displayed error in console:
UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Cannot set property 'message' of undefined

If remove the optional rule and add other - all work fine

[gustavohenke]

Thanks for the report. This is indeed a bug when using schema validation + optional as the first found key in a parameter object.

[gustavohenke]

Fix published in v4.1.1.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.