/*!
 * type-is
 * Copyright(c) 2014 Jonathan Ong
 * Copyright(c) 2014-2015 Douglas Christopher Wilson
 * MIT Licensed
 */
import { ContentType } from "content-type";
/**
 * Node.js HTTP request shape.
 */
export interface RequestLike {
    headers: Record<string, string | string[] | undefined>;
}
/**
 * Check if a request has a request body. A request with a body must either have
 * `transfer-encoding` or `content-length` headers set.
 */
export declare function hasBody(req: RequestLike): boolean;
/**
 * The default behavior of `lookup` handles only a few common shorthands.
 */
export declare function DEFAULT_LOOKUP(value: string): string | string[] | undefined;
export interface NormalizeOptions {
    lookup?: (value: string) => string | string[] | undefined;
}
/**
 * Normalize MIME type by:
 *
 * - If the string contains a `/`, then it is returned as the type.
 * - If the string starts with `+` (so it is a `+suffix` shorthand like `+json`), then it is expanded to contain the complete wildcard notation of `*\/*+suffix`.
 * - Else the string is assumed to be a file extension and the mapped media type is returned, or the original input if there is no mapping.
 */
export declare function normalize(value: string, options?: NormalizeOptions): string | string[];
/**
 * Compile an expected mime type into a reusable matcher.
 */
export declare function match(expected: string): (actual: string) => boolean;
export type ParameterValue = (key: string, value: string) => string;
/**
 * Normalize a parameter value for comparison.
 */
export declare function DEFAULT_PARAMETER_VALUE(key: string, value: string): string;
export interface TypeIsOptions extends NormalizeOptions {
    parameterValue?: ParameterValue;
}
export declare class TypeIs {
    private readonly hasParameters;
    private readonly patterns;
    private readonly parameterValue;
    /**
     * Compile a list of expected mime types into a reusable matcher.
     */
    constructor(types: readonly string[], options?: TypeIsOptions);
    /**
     * Check whether a content type matches one of the configured types.
     */
    is(value: string): string | undefined;
    /**
     * Check whether a request body matches one of the configured types.
     */
    request(req: RequestLike): string | undefined;
    contentType(contentType: Pick<ContentType, "type" | "parameters">): string | undefined;
}