Joi 基于更大的模式验证特定字段

Question

Say I have the following schema

const schema = Joi.object({
  title: Joi.string().required(),
  start_date: Joi.date().iso().required(),
  end_date: Joi.date().iso().greater(Joi.ref('start_date')).required()
});

In one occasion I'd like to validate the entire schema against an object

const obj = {
  title: 'abc',
  start_date: '2021-11-09',
  end_date: '2021-11-10'
}
const validationResult = schema.validate(obj);

And on the other I'd like to validate against part of the schema with my partial object (I don't want to be alarmed about a missing title, for instance)

const obj = {
  start_date: '2021-11-09',
  end_date: '2021-11-11'
}
const validationResult = schema/*sudo*/.onlyFields(['start_date', 'end_date']).validate(obj);

Is it possible? Workaround is having 2 schemas - titleSchema and dateSchema and concatinating

Answer 1

Solved using the schema.extract api

function joiSubSchema(base, fields) {
  return fields.reduce((schema, field) => {
    return schema.concat(Joi.object({
      [field]: base.extract(field)
    }));
  }, Joi.object());
}