next-mw/dist/index.d.ts

A middleware manager for Next.js

import { NextResponse, NextRequest, NextFetchEvent } from 'next/server';

/**
 * Allowed literal types for matcher conditions.
 */
type AllowedMatcherType = 'header' | 'query' | 'cookie';
/**
 * Matcher element type.
 * It accepts either an object with a literal type (one of AllowedMatcherType)
 * or an object with a general string, so that object literals without assertions work.
 */
type MatcherElement = {
    type: AllowedMatcherType;
    key: string;
    value?: string;
} | {
    type: string;
    key: string;
    value?: string;
};
/**
 * Interface for a matcher condition object.
 */
interface MatcherCondition {
    source: string;
    regexp?: string;
    locale?: boolean;
    has?: MatcherElement[];
    missing?: MatcherElement[];
}
/**
 * Matcher can be a string, a MatcherCondition object, or an array of these.
 */
type Matcher = string | MatcherCondition | (string | MatcherCondition)[];

/**
 * Type for a Next.js middleware result.
 */
type NextMiddlewareResult = NextResponse | Response | null | undefined | void;
/**
 * Type for a Next.js middleware function.
 */
type NextMiddleware = (req: NextRequest, ev: NextFetchEvent) => NextMiddlewareResult | Promise<NextMiddlewareResult>;
/**
 * Configuration option that uses only the "matcher" property.
 */
type ConfigMatcher = {
    matcher: Matcher;
    include?: never;
    exclude?: never;
};
/**
 * Configuration option that uses "include" and/or "exclude".
 */
type ConfigIncludeExclude = {
    matcher?: never;
    include?: Matcher;
    exclude?: Matcher;
};
/**
 * Configuration option type.
 */
type Config = ConfigMatcher | ConfigIncludeExclude;
/**
 * Middleware module type.
 * You can either use the "matcher" configuration
 * or the "include"/"exclude" configuration, but not both.
 */
type MiddlewareModule = {
    middleware: NextMiddleware;
    config?: Config;
};
/**
 * Composes multiple middlewares into a single middleware.
 * Matching logic:
 * - If "matcher" is defined, it is used exclusively.
 * - Otherwise, if "include" is defined, the request must match at least one pattern.
 * - And if "exclude" is defined, the request must not match any of the patterns.
 *
 * @param modules - List of imported middleware modules.
 * @returns The composed middleware function.
 */
declare function middlewares(...modules: MiddlewareModule[]): NextMiddleware;

export { type Config, type ConfigIncludeExclude, type ConfigMatcher, type MiddlewareModule, type NextMiddleware, type NextMiddlewareResult, middlewares };