arktype•3w ago

Can I add a default value to a type if everything other satisfies in a union type

const type1 = type({name: "string"}) const type2 = type({city: "string"}) const union = type1.or(type2) const result1 = union({name:"ankit"}) const result2 = union({city:"Ajmer"}) I want result1 to be {name: "ankit",kind:"name"} I want result2 to be {city:"Ajmer",kind:"city"} or better const [kind,result] = union({name:"ankit"}) here kind will be "name" and result will be {name:"ankit"} and kind type will be "name"| "city" can I add these default value of kind in the type definitions so that if parsed with that validator from the union the kind is added

33 Replies

Dimava•3w ago

You should be able to union morphs If they have incompatible inputs What if you have {city, name}? 🤔 @aabad_ankit

import { type } from 'arktype'

let c = type({city: 'string', '+': 'reject'}).pipe(o => ({...o, type: 'city'}))
let n = type({name: 'string', '+': 'reject'}).pipe(o => ({...o, type: 'name'}))

let cn = type([c, '|', n])

console.log(
    cn({city: 'foo'}),
    cn({name: 'foo'}),
    '\n' + cn({city: 'foo', name: 'foo'}) + '\n',
    cn({}) + '',
)

import { type } from 'arktype'

let c = type({city: 'string', '+': 'reject'}).pipe(o => ({...o, type: 'city'}))
let n = type({name: 'string', '+': 'reject'}).pipe(o => ({...o, type: 'name'}))

let cn = type([c, '|', n])

console.log(
    cn({city: 'foo'}),
    cn({name: 'foo'}),
    '\n' + cn({city: 'foo', name: 'foo'}) + '\n',
    cn({}) + '',
)

{
  city: "foo",
  type: "city",
} {
  name: "foo",
  type: "name",
} 
name must be removednull or city must be removednull
 city must be a string (was missing) or name must be a string (was missing)

{
  city: "foo",
  type: "city",
} {
  name: "foo",
  type: "name",
} 
name must be removednull or city must be removednull
 city must be a string (was missing) or name must be a string (was missing)

Wait @ArkDavid wtf is removednull

aabad_ankit•3w ago

@Dimava the Monoreaper If I try this

const baseType = type({ id: "string" }).pipe((o) => {
  return { userId: o.id };
});

const newType = baseType.and({name: "string"})

console.log(newType({name:"ankit",id:"102"}))

const baseType = type({ id: "string" }).pipe((o) => {
  return { userId: o.id };
});

const newType = baseType.and({name: "string"})

console.log(newType({name:"ankit",id:"102"}))

1. merge is not available on baseType 2. I am not getting the name in the result, it seems the pipe operation is applied in the end

ssalbdivad•3w ago

You can't apply structural operations like merge on a morphed type. For now at least, I'd just create a unions of the inputs then manage the discrimination logic in the pipe implementation from the union

ssalbdivad•3w ago

See https://github.com/arktypeio/arktype/discussions/1080

GitHub

How should you .pipe to a type constructed with or? · arktypeio...

I have the following: const objSchema = type({ action: "'scheduled' | 'rescheduled' | 'canceled' | 'changed'", id: "parse.integer", calendarID: &...

ssalbdivad•3w ago

It would be theoretically possible to discriminate using strict key presence but it's not implemented yet: https://github.com/arktypeio/arktype/issues/786

aabad_ankit•3w ago

I need to learn a lot 🙂 . This library is just awesome.

ssalbdivad•3w ago

Thank you 😊 Working on more docs now!

aabad_ankit•3w ago

docs will certainly help. @ArkDavid How can I get better error msg for this

const type1 = type({"name": "string",age:"number"})
const type2 = type({"city": "string"})

const union = type([type1,"|",type2])
const result = union({"age":12})
console.log(result.summary)

const type1 = type({"name": "string",age:"number"})
const type2 = type({"city": "string"})

const union = type([type1,"|",type2])
const result = union({"age":12})
console.log(result.summary)

prints "name must be a string (was missing) or city must be a string (was missing)" since age is already there shouldn't it just say "name must be a string (was missing) "

ssalbdivad•3w ago

That would require the issue I mentioned before where key presence could be used as a discriminant If you want total control over how the error messages are handled you could use .narrow and create them yourself If you had a discriminant key like kind: "person" kind: "city" or similar, it would check that first, then give the error message based on the branch it is on It could theoretically do that based on key presence once that issue is implemented Oh I guess in those cases you don't have onUndeclaredKeys at all though So the reason it would give both is because it is true that {city: "foo", age: 12} would also be valid Seems to be missing an "or", will fix that But wait null isn't even allowed

ssalbdivad•3w ago

Whoops found it

aabad_ankit•3w ago

I am getting name must be a string (was missing) or city must be a string (was missing) for both the code snippets below.

const type1 = type({"name": "string",age:"number","+": "delete"})
const type2 = type({"city": "string","+": "delete"})
const union = type([type1,"|",type2])
const result = union({"age":12})
console.log(result.summary)

const type1 = type({"name": "string",age:"number","+": "delete"})
const type2 = type({"city": "string","+": "delete"})
const union = type([type1,"|",type2])
const result = union({"age":12})
console.log(result.summary)

and

const type1 = type({ name: "string", age: "number", "+": "delete" }).pipe(
  (o) => {
    return { ...o, kind: "person" as const };
  }
);
const type2 = type({ city: "string", "+": "delete" }).pipe((o) => {
  return { ...o, kind: "city" as const };
});

const union = type([type1, "|", type2]);
const result = union({ age: 12, kind: "city" });
console.log(result.summary);

const type1 = type({ name: "string", age: "number", "+": "delete" }).pipe(
  (o) => {
    return { ...o, kind: "person" as const };
  }
);
const type2 = type({ city: "string", "+": "delete" }).pipe((o) => {
  return { ...o, kind: "city" as const };
});

const union = type([type1, "|", type2]);
const result = union({ age: 12, kind: "city" });
console.log(result.summary);

ssalbdivad•3w ago

That is expected, it's validating the input not the output. Adding a kind: "city" after it's already been validated wouldn't change anything

aabad_ankit•2w ago

Oh Yeah, Understood 👍 @ArkDavid @Dimava the Monoreaper What will be the most idiomatic way to do the validation for such union types to get correct error msg. Do I need to check for the properties and do validation by creating a validator map

import { type } from "arktype";
import { keys } from "remeda";

const nameArk = type({ name: "string" }).onDeepUndeclaredKey("delete");
const cityArk = type({ city: "string" }).onDeepUndeclaredKey("delete");
const vm = {
  "name": nameArk,
  "city": cityArk
};
const input = { name: "ark" };
let result: typeof nameArk.infer | typeof cityArk.infer;
for (const key of keys(vm)) {
  if (key in input) {
    result = vm[key].assert(input);
    break;
  }
}

// peform pipe operation here

import { type } from "arktype";
import { keys } from "remeda";

const nameArk = type({ name: "string" }).onDeepUndeclaredKey("delete");
const cityArk = type({ city: "string" }).onDeepUndeclaredKey("delete");
const vm = {
  "name": nameArk,
  "city": cityArk
};
const input = { name: "ark" };
let result: typeof nameArk.infer | typeof cityArk.infer;
for (const key of keys(vm)) {
  if (key in input) {
    result = vm[key].assert(input);
    break;
  }
}

// peform pipe operation here

This is getting verbose. I am giving example of just one field but my inputs are larger and I have 5 different types of input. If I could have done union then I would have declared on deepUndeclaredkey("delete") on just the union as well as the pipe on the union

ssalbdivad•2w ago

What is the actual problem you are having?

aabad_ankit•2w ago

const nameArk = type({ name: "string", age: "number" }).onDeepUndeclaredKey(
  "delete"
);
const cityArk = type({ city: "string" }).onDeepUndeclaredKey("delete");
const input = { name: "ark" };
const result = nameArk.or(cityArk)(input)
console.log(result.summary)

const nameArk = type({ name: "string", age: "number" }).onDeepUndeclaredKey(
  "delete"
);
const cityArk = type({ city: "string" }).onDeepUndeclaredKey("delete");
const input = { name: "ark" };
const result = nameArk.or(cityArk)(input)
console.log(result.summary)

This prints age must be a number (was missing) or city must be a string (was missing). I just want the error msg to be age must be a number (was missing) to do that I am currently doing something like this

const vm = {
  "name": nameArk,
  "city": cityArk
};
const input = { name: "ark" };
let result: typeof nameArk.infer | typeof cityArk.infer;
for (const key of keys(vm)) {
  if (key in input) {
    result = vm[key].assert(input);
    break;
  }
}

const vm = {
  "name": nameArk,
  "city": cityArk
};
const input = { name: "ark" };
let result: typeof nameArk.infer | typeof cityArk.infer;
for (const key of keys(vm)) {
  if (key in input) {
    result = vm[key].assert(input);
    break;
  }
}

so I wanted to know if there is more idiomatic way to do this

Gaming

Programming

Can I add a default value to a type if everything other satisfies in a union type