Unions and enums from an array

I might be missing something, but it seems this is currently not possible, but would be a great time/code saver:

const STATUSES = ['Assigned', 'In Progress', 'On Location', 'Succeeded', 'Failed'];
const StatusSchema = z.union(STATUSES.map(z.literal));
const StatusSchema2 = z.enum(STATUSES);

[ivosabev]

With as const makes it readonly, but won’t work either.

const fishTypes = ['Salmon', 'Tuna', 'Trout'] as const;
const FishEnum = z.enum(fishTypes);

Argument of type 'readonly ["Salmon", "Tuna", "Trout"]' is not assignable to parameter of type '[string, ...string[]]'.
  The type 'readonly ["Salmon", "Tuna", "Trout"]' is 'readonly' and cannot be assigned to the mutable type '[string, ...string[]]'.

Destructuring it works:

const fishTypes = ['Salmon', 'Tuna', 'Trout'] as const;
const FishEnum = z.enum([...fishTypes]);

Maybe the internals of z.enum and z.union could be touched to allow such cases?

[dvargas92495]

hey @colinhacks I’m running into something similar here.

I have the following constant array:

const WORK_TYPES = [
  { id: 1, name: "Task" },
  { id: 2, name: "Project" },
  { id: 3, name: "Initiative" },
] as const;

I’d like to create an enum type that is a union of the name fields of that array. Here’s what I tried doing:

const workType = z.enum(WORK_TYPES.map((w) => w.name));
// Typescript: Source provides no match for required element at position 0 in target

What I think is happening is: .map produces a <union of strings>[], which is technically not guaranteed to have a first element, despite WORK_TYPES being a constant. but the type of enum requires at least one element (which makes intuitive sense).

This theory is supported by the following working:

const workType = z.enum(
        [WORK_TYPES[0].name, ...WORK_TYPES.slice(1).map((w) => w.name)]
);

Any thoughts on a better workaround instead of ^? Or is this an issue with the enum input type?