UNPKG

type-plus

Version:
58 lines 1.79 kB
import type { IsAnyOrNever } from '../mix_types/any_or_never_type.js'; /** * Check if the type `T` is `string` or string literals. * * ```ts * type R = StringType<string> // string * type R = StringType<''> // '' * type R = StringType<'1'> // '1' * * type R = StringType<string | boolean> // never * type R = StringType<never> // never * type R = StringType<unknown> // never * ``` */ export type StringType<T, Then = T, Else = never> = IsAnyOrNever<T, Else, [T] extends [string] ? Then : Else>; /** * Is the type `T` `string` or string literals. * * ```ts * type R = IsString<string> // true * type R = IsString<''> // true * type R = IsString<'a'> // true * * type R = IsString<string | boolean> // false * type R = IsString<never> // false * type R = IsString<unknown> // false * ``` */ export type IsString<T, Then = true, Else = false> = StringType<T, Then, Else>; /** * Check if the type `T` is not `string` nor string literals. * * ```ts * type R = NotStringType<string> // never * type R = NotStringType<''> // '' * type R = NotStringType<'a'> // 'a' * * type R = NotStringType<string | boolean> // string | boolean * type R = NotStringType<never> // never * type R = NotStringType<unknown> // unknown * ``` */ export type NotStringType<T, Then = T, Else = never> = StringType<T, Else, Then>; /** * Is the type `T` not `string` nor string literals. * * ```ts * type R = IsNotString<string> // false * type R = IsNotString<''> // false * type R = IsNotString<'a'> // false * * type R = IsNotString<string | boolean> // true * type R = IsNotString<never> // true * type R = IsNotString<unknown> // true * ``` */ export type IsNotString<T, Then = true, Else = false> = StringType<T, Else, Then>; //# sourceMappingURL=string_type.d.ts.map