import { type ChangeNotifier, type FileSystemPort } from "../ports.js";
export interface MemoryFileSystemOptions {
    /**
     * The project to start from, as project-relative path → file content. Parent
     * directories are implied and don't need listing.
     */
    files?: Record<string, string>;
    /**
     * Top-level directories whose changes are reported to `onChange` listeners.
     * Defaults to the same set chokidar watches on Node, so the preview's
     * live-reload behaviour matches the CLI's rather than being broader.
     */
    watchedDirs?: readonly string[];
    /** Injectable clock, so tests can control mtimes. */
    now?: () => Date;
    /**
     * The mtime the seeded project starts with. Defaults to now.
     *
     * Worth setting to a constant wherever the same seed is loaded more than
     * once — a Worker builds one of these per isolate, and if each picked its own
     * startup time, a client that read a file from one isolate would be told its
     * save conflicts when it landed on another. The file it read and the file it
     * is saving over are byte-identical; only the clock disagreed.
     */
    seedMtime?: Date;
}
export interface MemoryFileSystem extends FileSystemPort, ChangeNotifier {
    /** Discards all edits and returns to the seeded project. */
    reset(): void;
}
/**
 * A `FileSystemPort` held entirely in memory — what the per-PR preview Worker
 * runs against, since a Worker has no filesystem.
 *
 * Directories are implied by the paths of the files inside them, plus any
 * created explicitly, which is enough for a project tree and avoids maintaining
 * a parallel directory structure that could disagree with the files.
 *
 * It doubles as the `ChangeNotifier`: writes report themselves, so the SPA's
 * live-reload path stays exercised in the preview instead of going quiet with
 * no chokidar to drive it.
 */
export declare function createMemoryFileSystem(options?: MemoryFileSystemOptions): MemoryFileSystem;