A
arktype•2w ago
CodyC

How do I name a morph?

import { type } from "arktype"

// I have some class that validates or throws. I want to parse an instance of that from a config file.
class ValidatedUserID {
    static fromString(value: string): ValidatedUserID {
        return new ValidatedUserID(value)
    }
    private constructor(readonly data: string) {}
}

const UserID = type("string")
    .describe("a userID")
    .pipe.try(
        ValidatedUserID.fromString
     )
    .describe("No, really, this is a user ID")

const User = type({
    id: UserID
})

const user = User.assert({
    iD: "typo, oops"
})
import { type } from "arktype"

// I have some class that validates or throws. I want to parse an instance of that from a config file.
class ValidatedUserID {
    static fromString(value: string): ValidatedUserID {
        return new ValidatedUserID(value)
    }
    private constructor(readonly data: string) {}
}

const UserID = type("string")
    .describe("a userID")
    .pipe.try(
        ValidatedUserID.fromString
     )
    .describe("No, really, this is a user ID")

const User = type({
    id: UserID
})

const user = User.assert({
    iD: "typo, oops"
})
Throws:
TraversalError: id must be a morph (was missing)
How can I rename this from "a morph" to a more meaningful message for users?
3 Replies
ssalbdivad
ssalbdivad•2w ago
Oh yeah that sucks and should not be included in the error message will fix
CodyC
CodyCOP•2w ago
Other than this, so far ArkType has the best default error output of any of the TS validation libraries I've used. ❤️ For writing little CLI tools that parse JSON data or config files, it's so nice to be able to just throw the error and give the end user something very easy to make sense of w/o having to roll error formatting code all the time.
ssalbdivad
ssalbdivad•2w ago
That's great to hear! I still think there's more we can do to make discriminated union errors clearer but overall it is definitely a big advantage I'm fixing that case right now. There should never be references to internal concepts like that in the default message That error message is fixed in 2.1.11

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