Z.enum get the input tuple

[thibaultdenis014]

Hey everyone,

with the following schema, how could I get the type of tuple that is inside the schema ?

const weightUnit = z.enum(["kg", "lbs"]);

I know I can do somehting like typeof weightUnit.options but its type is not what I am looking for, I get ("kg"|"lbs")[], and I want readonly ["kg", "lbs"]

[dosubot[bot]]

Hi @thibaultdenis014! I'm Dosu and I’m helping the zod team.

Zod doesn't expose the original tuple type from a z.enum schema at runtime—.options gives you a ("kg" | "lbs")[], not the tuple type you want. To preserve and access the tuple type (readonly ["kg", "lbs"]), declare your values as a constant with as const, then use that for both the schema and your type:

const weightUnitValues = ["kg", "lbs"] as const;
const weightUnit = z.enum(weightUnitValues);
type WeightUnitTuple = typeof weightUnitValues; // readonly ["kg", "lbs"]

This is a TypeScript pattern, not a Zod-specific feature. Zod's runtime schema only keeps the values as an array, so the tuple type is only available at the type level when you use as const on your input array. More details in the Zod docs.

If this answers your question, feel free to close the issue!

To reply, just mention @dosu.

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