import { type ImmutableArray } from "../util/array.js";
import { type Entity } from "../util/entity.js";
import { StringSchema, type StringSchemaOptions } from "./StringSchema.js";
/** Allowed options for `EntitySchema` with specific types */
export interface EntitySchemaOptions<T extends string> extends StringSchemaOptions {
    readonly types?: ImmutableArray<T> | undefined;
}
/** Validate a file name matching one or more extensions. */
export declare class EntitySchema<T extends string> extends StringSchema {
    readonly types: ImmutableArray<T> | undefined;
    constructor({ one, title, types, ...options }: EntitySchemaOptions<T>);
    validate(unsafeValue?: unknown): Entity<T>;
}
/** Valid file, e.g. `challenge:a1b2c3` */
export declare const ENTITY: EntitySchema<string>;
/** Valid optional file, e.g. `file.txt`, or `null` */
export declare const NULLABLE_ENTITY: import("./NullableSchema.js").NullableSchema<`${string}:${string}`>;