import type { FileTypes } from "../util/file.js";
import { StringSchema, type StringSchemaOptions } from "./StringSchema.js";
/** Allowed options for `FileSchema` */
export interface FileSchemaOptions extends StringSchemaOptions {
    readonly types?: FileTypes | undefined;
}
/** Validate a file name matching one or more extensions. */
export declare class FileSchema extends StringSchema {
    readonly types: FileTypes | undefined;
    constructor({ one, title, types, ...options }: FileSchemaOptions);
    validate(unsafeValue?: unknown): string;
}
/** Valid file, e.g. `file.txt` */
export declare const FILE: FileSchema;
/** Valid optional file, e.g. `file.txt`, or `null` */
export declare const NULLABLE_FILE: import("./NullableSchema.js").NullableSchema<string>;