When our object fails validation, we should generate the same human-readable error messages as we did before. To do this, we must process the errors stored at ajvValidate.errors, and use them to generate human-readable messages. Thus, create a new module at src/validators/errors/messages.js, and copy the following message generator:

function generateValidationErrorMessage(errors) {
  const error = errors[0];

  if (error.dataPath.indexOf('.profile') === 0) {
    return 'The profile provided is invalid.';
  }
  if (error.keyword === 'required') {
    return 'Payload must contain at least the email and password fields';
  }
  if (error.keyword === 'type') {
    return 'The email and password fields must be of type string';
  }
  if (error.keyword === 'format') {
    return 'The email field must be a valid email.';
  }
  return 'The object is invalid';
}

export default generateValidationErrorMessage;

The generateValidationErrorMessage function extracts the first error object from the ajvValidate.errors array, and use it to generate the appropriate error message. There's also a generic, default error message in case none of the conditionals apply.