How to describe a type that's a union of string with a pattern?

[ildede]

I currently have a type defined like this:

export type MyType = 'master' | 'companion' | `master-${number}`;

I'm trying to define the same thing with superstruct, but I'm a bit lost as I can't reach the same definition.
Looking into the documentation didn't help me find other possible solutions, so here what I tried so far.

Thanks in advance!

First try (enums)

const MyType: Describe<MyType> = enums(['master', 'companion', `master-${number()}`]);

I get

Type "master" | "companion" | `master-${string}` is not assignable to type MyType
    Type `master-${string}` is not assignable to type MyType

Second try (union and pattern)

const MyType: Describe<MyType> = union([literal('master'), literal('companion'), pattern(string(), /master-\d+/)]);

I get

TS2322: Type Struct<string, null> is not assignable to type Describe<MyType>
    Types of property TYPE are incompatible.
        Type string is not assignable to type MyType

Third try (pattern)

const MyType: Describe<MyType> = pattern(string(), /^master$|^companion$|^master-\d+$/);

I get

TS2322: Type Struct<string, null> is not assignable to type Describe<MyType>
    Types of property TYPE are incompatible.
        Type string is not assignable to type MyType

[yeoffrey]

cc: @arturmuller

To my understanding I don't think that there is a way in Superstruct to handle templated types like this. I also looked through the documentation and old issues to see if there was a discussion around this but couldn't find anything.

In terms of your examples, they all should work for validation but as I understand it you want the type inference off the struct. I don't think that is supported right now.

Thank you for the detailed issue!