[Question] dealing with parent children relationship

[davidchase]

👋this library has been awesome for validating properties both static and dynamic which is great so thanks!

my question has there been any thoughts when for example you need to find duplicates

from the docs:

const input = {
  id: 4,
  users: {
    one: {firstName: 'foobar', lastName: 'action'},
    two: {firstName: 'foo', lastName: 'bar'},
    three: {firstName: 'foobar', lastName: 'Action'},
  }
}

const validationRules = {
  id: [[ notEmpty, notEmptyMsg('id') ]],
  users: map(always(userSpec)),
}

we can easily validate the children individual properties such as firstName, lastName

but in order to find the duplicates between each users.one.firstName, users.two.firstName, etc child we need the actual users object to compare each child

the only thing i can think of is maybe updating the validationRules for users to pre-process the input and then pass the function to merge with the existing userSpec

dont know if anyone else had a similar experience so i thought i would ask

cheers

[busypeoples]

Hi! Thanks for the feedback! Will look into this, either today or tomorrow.

[davidchase]

sounds good thanks :)

[busypeoples]

@davidchase I will finally have the time to look into the this, this week!

[davidchase]

@busypeoples cool sounds good, let me know what you come up with :)

[busypeoples]

Here's a possible way to tackle the problem. But we probably will need something better than this in the long run.

// predicates

const notEmpty = compose(not, isEmpty);
const hasCapitalLetter = a => /[A-Z]/.test(a);
const isGreaterThan = curry((len, a) => a > len);
const isLengthGreaterThan = len => compose(isGreaterThan(len), prop("length"));
const duplicate = (all, item) => filter(i => item === i, all).length <= 1;
const noDuplicate = all => (a, data) => duplicate(all, a);
// error messages

const notEmptyMsg = field => `${field} should not be empty.`;
const minimumMsg = (field, len) =>
  `Minimum ${field} length of ${len} is required.`;
const capitalLetterMsg = field =>
  `${field} should contain at least one uppercase letter.`;

const input = {
  id: 4,
  users: {
    one: { firstName: "foobar", lastName: "barA" },
    two: { firstName: "foo", lastName: "barA" },
    three: { firstName: "foobar", lastName: "other-Input" }
  }
};

const names = pluck("lastName", Object.values(input.users));

const userSpec = {
  firstName: [[isLengthGreaterThan(5), minimumMsg("firstName", 6)]],
  lastName: [
    [hasCapitalLetter, capitalLetterMsg],
    [noDuplicate(names), "Duplicate Last Name found."]
  ]
};

const validationRules = {
  id: [[notEmpty, notEmptyMsg("id")]],
  users: map(always(userSpec))
};

spected(validationRules, input);

https://codesandbox.io/s/1v69583wx7

[davidchase]

yeah thats a good one, i tried it out with a multimap structure in order to avoid passing in the context twice. so i compose the noDuplicates with a simple hash + array multimap.