Joi validation - how to make a field optional based on input

Question

I've been trying to implement the following joi validation.

joiSchema = Joi.object().keys({
      taskno: Joi.string().alphanum().required().uppercase().trim(),
      taskstatus: Joi.valid('G', 'C', 'I', 'S'),
      taskpriority: Joi.number().integer().max(5).min(1),
      stuckreason: Joi.string().allow('').max(200).trim(),
      dttarget: Joi.date().iso(),
      dtdue: Joi.date().iso(),
      dtcomplete: Joi.when('taskstatus', {
        is: Joi.valid('C', 'I'),
        then: Joi.date().iso().required(),
      })
    });

My object contains taskno, dttarget and dtdue and I only want to validate this.
If i joi.validate() object it returns error "dtcomplete is required" .
Is there a way to optionally check "dtcomplete"

Answer 1

Try the condition for dtcomplete along with exist() in Joi

So the code will be like below

joiSchema = Joi.object().keys({
  taskno: Joi.string().alphanum().required().uppercase().trim(),
  taskstatus: Joi.valid('G', 'C', 'I', 'S'),
  taskpriority: Joi.number().integer().max(5).min(1),
  stuckreason: Joi.string().allow('').max(200).trim(),
  dttarget: Joi.date().iso(),
  dtdue: Joi.date().iso(),
  dtcomplete: Joi.when('taskstatus', {
    is: Joi.exist().valid('C', 'I'),
    then: Joi.date().iso().required(),
  })
});

Only the difference is at is: Joi.exist().valid('C', 'I'),