import type * as vite from 'vite';
import type { AstroSettings } from '../types/astro.js';
/**
 * Outcome of the trailing-slash evaluation for a dev-server request.
 *
 * - **`next`** — The URL is acceptable. Pass the request through to the next
 *   middleware / route handler unchanged.
 * - **`redirect`** — The URL contains duplicate trailing slashes (e.g.
 *   `/about//`). The client should be permanently redirected (301) to the
 *   collapsed form (`/about/`) so crawlers and browsers update their links.
 * - **`reject`** — The URL's trailing-slash style conflicts with the project's
 *   `trailingSlash` config (`'always'` or `'never'`). The dev server responds
 *   with a 404 and a human-readable error page explaining the mismatch, giving
 *   the developer immediate feedback that their link is wrong before it reaches
 *   production.
 */
export type TrailingSlashDecision = {
    action: 'next';
} | {
    action: 'redirect';
    status: 301;
    location: string;
} | {
    action: 'reject';
    status: 404;
    pathname: string;
};
/**
 * Pure decision function for trailing-slash dev-server behavior.
 *
 * Evaluates a decoded `pathname`, the query-string portion (including leading
 * `?`), and the project's `trailingSlash` config and returns the action the
 * middleware should take. The middleware is responsible for translating the
 * decision into an HTTP response.
 */
export declare function evaluateTrailingSlash(pathname: string, search: string, trailingSlash: 'always' | 'never' | 'ignore'): TrailingSlashDecision;
export declare function trailingSlashMiddleware(settings: AstroSettings): vite.Connect.NextHandleFunction;