Joi 验证架构 - 两个字段不能具有相同的值

Question

Assume I have the following schema:

var schema = {
  fieldOne: Joi.string().required(),
  fieldTwo: Joi.string().required()
};

Is it possible to set a validation rule that checks if both fields have different values?

Answer 1

Yes it is. You do this by making use of Joi.ref and Joi.invalid (aliased to Joi.disallow ). For your particular example, it would be:

var assert = require('assert');
var Joi = require('joi');

var schema = Joi.object().keys({
  fieldOne: Joi.string().required(),
  fieldTwo: Joi.string().disallow(Joi.ref('fieldOne')).required()
});

And testing it yields us what we would expect:

assert.ok(Joi.validate(4, schema).error !== null);
assert.ok(Joi.validate({ fieldOne: 'a', fieldTwo: 'a' }, schema).error !== null);
assert.ok(Joi.validate({ fieldOne: 'a', fieldTwo: 'b' }, schema).error === null);

It works by referencing fieldOne in our definition of fieldTwo and disallowing the same value.

Answer 2

Unfortunately, I'm not sure that a direct validation for different values exists, but you can try to use array#unique() instead:

var schema = {
  fieldOne: Joi.string().required(),
  fieldTwo: Joi.string().required(),
  fieldOneAndTwo: Joi.array().unique()
};

and set fieldOneAndTwo = [fieldOne, fieldTwo] before the validation.