Enums
Zod enums
const FishEnum = z.enum(["Salmon", "Tuna", "Trout"]);
type FishEnum = z.infer<typeof FishEnum>;
// 'Salmon' | 'Tuna' | 'Trout'
z.enum
is a Zod-native way to declare a schema with a fixed set of allowable string values. Pass the array of values directly into z.enum()
. Alternatively, use as const
to define your enum values as a tuple of strings. See the const assertion docs for details.
const VALUES = ["Salmon", "Tuna", "Trout"] as const;
const FishEnum = z.enum(VALUES);
This is not allowed, since Zod isn't able to infer the exact values of each element.
const fish = ["Salmon", "Tuna", "Trout"];
const FishEnum = z.enum(fish);
Enum
To get autocompletion with a Zod enum, use the .enum
property of your schema:
FishEnum.enum.Salmon; // => autocompletes
FishEnum.enum;
/*
=> {
Salmon: "Salmon",
Tuna: "Tuna",
Trout: "Trout",
}
*/
You can also retrieve the list of options as a tuple with the .options
property:
FishEnum.options; // ["Salmon", "Tuna", "Trout"];
Exclude/Extract
You can create subsets of a Zod enum with the .exclude
and .extract
methods.
const FishEnum = z.enum(["Salmon", "Tuna", "Trout"]);
const SalmonAndTrout = FishEnum.extract(["Salmon", "Trout"]);
const TunaOnly = FishEnum.exclude(["Salmon", "Trout"]);
Native enums
Zod enums are the recommended approach to defining and validating enums. But if you need to validate against an enum from a third-party library (or you don't want to rewrite your existing enums) you can use z.nativeEnum()
.
Numeric enums
enum Fruits {
Apple,
Banana
}
const FruitEnum = z.nativeEnum(Fruits);
type FruitEnum = z.infer<typeof FruitEnum>; // Fruits
FruitEnum.parse(Fruits.Apple); // passes
FruitEnum.parse(Fruits.Banana); // passes
FruitEnum.parse(0); // passes
FruitEnum.parse(1); // passes
FruitEnum.parse(3); // fails
String enums
enum Fruits {
Apple = "apple",
Banana = "banana",
Cantaloupe // you can mix numerical and string enums
}
const FruitEnum = z.nativeEnum(Fruits);
type FruitEnum = z.infer<typeof FruitEnum>; // Fruits
FruitEnum.parse(Fruits.Apple); // passes
FruitEnum.parse(Fruits.Cantaloupe); // passes
FruitEnum.parse("apple"); // passes
FruitEnum.parse("banana"); // passes
FruitEnum.parse(0); // passes
FruitEnum.parse("Cantaloupe"); // fails
Const enums
The .nativeEnum()
function works for as const
objects as well. ⚠️ as const
requires TypeScript 3.4+!
const Fruits = {
Apple: "apple",
Banana: "banana",
Cantaloupe: 3
} as const;
const FruitEnum = z.nativeEnum(Fruits);
type FruitEnum = z.infer<typeof FruitEnum>; // "apple" | "banana" | 3
FruitEnum.parse("apple"); // passes
FruitEnum.parse("banana"); // passes
FruitEnum.parse(3); // passes
FruitEnum.parse("Cantaloupe"); // fails
You can access the underlying object with the .enum
property:
FruitEnum.enum.Apple; // "apple"