A
arktype•13mo ago
Micha

How to Union in scope()?

Union 1 will be resolved as I would expect to ts?: string | TimeStub | undefined;: 
export const myType = type({
    "id?": "string",
    "coll?": "string",
    "ts?": ["string", "|", ["instanceof", TimeStub] as Infer<TimeStub>]
})
export const myType = type({
    "id?": "string",
    "coll?": "string",
    "ts?": ["string", "|", ["instanceof", TimeStub] as Infer<TimeStub>]
})
But Union 2 
export const types = scope({
    account: {
        user: ["user", "|", ["instanceof", TimeStub] as Infer<TimeStub>],
        provider: "provider",
        providerUserId: "string"
    },
    user: {
        name: "string",
        "accounts?": "account[]"
    },
    provider: "'GitHub'|'Google'"
})
export const types = scope({
    account: {
        user: ["user", "|", ["instanceof", TimeStub] as Infer<TimeStub>],
        provider: "provider",
        providerUserId: "string"
    },
    user: {
        name: "string",
        "accounts?": "account[]"
    },
    provider: "'GitHub'|'Google'"
})
will be resolved to 
account: { [k in keyof ({
        user: any;
        provider: "GitHub" | "Google";
        providerUserId: string;
    } & {} & {})]: ({
        user: any;
        provider: "GitHub" | "Google";
        providerUserId: string;
    } & {} & {})[k]; };
account: { [k in keyof ({
        user: any;
        provider: "GitHub" | "Google";
        providerUserId: string;
    } & {} & {})]: ({
        user: any;
        provider: "GitHub" | "Google";
        providerUserId: string;
    } & {} & {})[k]; };
although I would expect something like user: User | TimeStub If I'm trying to do the same with the base union syntax that I found "ts?": "string|['instanceof', TimeStub] as Infer<TimeStub>" I get a type error 
Type '"string|['instanceof', TimeStub] as Infer<TimeStub>"' is not assignable to type '"string|string" | "string|number" | "string|bigint" | "string|boolean" | "string|symbol" | "string|undefined" | "string|object" | "string|null" | "string|Date" | "string|Error" | ... 25 more ... | "string|parsedDate"'.(2322)
demo.ts(44, 5): The expected type comes from property 'ts?' which is declared here on type '{ "id?": "string"; "coll?": "string"; "ts?": "string|string" | "string|number" | "string|bigint" | "string|boolean" | "string|symbol" | "string|undefined" | "string|object" | "string|null" | ... 27 more ... | "string|parsedDate"; }'
Type '"string|['instanceof', TimeStub] as Infer<TimeStub>"' is not assignable to type '"string|string" | "string|number" | "string|bigint" | "string|boolean" | "string|symbol" | "string|undefined" | "string|object" | "string|null" | "string|Date" | "string|Error" | ... 25 more ... | "string|parsedDate"'.(2322)
demo.ts(44, 5): The expected type comes from property 'ts?' which is declared here on type '{ "id?": "string"; "coll?": "string"; "ts?": "string|string" | "string|number" | "string|bigint" | "string|boolean" | "string|symbol" | "string|undefined" | "string|object" | "string|null" | ... 27 more ... | "string|parsedDate"; }'
https://stackblitz.com/edit/rzkceh-eodur9?file=demo.ts
Micha Mailänder
StackBlitz
Fayxym (forked) - StackBlitz
ArkType demo demo
5 Replies
ssalbdivad
ssalbdivad•13mo ago
In terms of the syntax, I'd expect something like this: 
export const types = scope({
    timeStub: ["instanceof", TimeStub] as Infer<TimeStub>,
    account: {
        user: "user|timeStub",
        provider: "provider",
        providerUserId: "string"
    },
    user: {
        name: "string",
        "accounts?": "account[]"
    },
    provider: "'GitHub'|'Google'"
})
export const types = scope({
    timeStub: ["instanceof", TimeStub] as Infer<TimeStub>,
    account: {
        user: "user|timeStub",
        provider: "provider",
        providerUserId: "string"
    },
    user: {
        name: "string",
        "accounts?": "account[]"
    },
    provider: "'GitHub'|'Google'"
})
if you're in a scope anyways, it usually makes sense to give expressions like that their own alias so you can reuse them easily and with the normal string syntax. That said, the type inference is wrong for this. It seems like the normal strategy I added to avoid mapping over custom types and clobbering the original name doesn't work in scopes. Would be great if you could log an issue to make sure this is resolved!
Micha
MichaOP•13mo ago
Added an issue https://github.com/arktypeio/arktype/issues/915 - maybe you can check it if it describes the problem in the right way 🙂
GitHub
Type inference wrong for union with class · Issue #915 · arktypeio/...
Report a bug for the given union export const types = scope({ timeStub: ["instanceof", TimeStub] as Infer<TimeStub>, account: { user: "user|timeStub", provider: "prov...
ssalbdivad
ssalbdivad•13mo ago
Yes this is perfect, thank you! I am getting ready for a 2.0 prerelease. I'll make sure this is resolved there, and if it can be done easily, will port it to alpha as well.
Micha
MichaOP•13mo ago
I can also upgrade to 2.0 if this is somewhat stable, I was simply installing @latest 🙂
ssalbdivad
ssalbdivad•13mo ago
No don't it's not stable at all with the last release. I am hoping that the release I'm working on now will be usable outside a few features like cyclic generics etc. though

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