createEnum

The createEnum() function creates an immutable, typed string enum. The returned object exposes each value as a key, plus has(), toTuple(), and contract().

Interactive example

Syntax

type Enum<
	GenericInputs extends [string, ...string[]]
> = {
	[Prop in GenericInputs[number]]: Prop;
} & {
	toTuple(): GenericInputs;
	has(value: string): value is GenericInputs[number];
	contract<
		GenericContractValue extends GenericInputs[number]
	>(
		...args: ...
	): Enum<GenericInputs>;
};

function createEnum<
	GenericInput extends string,
	GenericInputs extends [GenericInput, ...GenericInput[]]
>(
	values: GenericInputs
): Enum<GenericInputs>;

type GetEnumValue<
	GenericEnum extends { toTuple(): [string, ...string[]] }
> = ReturnType<GenericEnum["toTuple"]>[number];

Parameters

• values : Non-empty tuple of strings (the enum members).

Return value

An immutable enum object with:

• The named properties (same key/value).
• toTuple() to retrieve the typed tuple.
• has(value) to test a runtime value with a type guard.
• contract<...>() to verify at type level that the enum exactly matches an expected union.

See also

• kind - Runtime/type tags