/**
 * A two-phase writer for one generation run: every file is staged next to its
 * final location under a temporary name, and only once the whole set is on disk
 * are the temporaries renamed into place.
 *
 * The failure mode it exists for is **partial trees**. Writing straight to the
 * final paths meant a failure halfway through (a `_helpers` path occupied by a
 * regular file, a full disk) left some generated files behind and others missing
 * — a tree that compiles against a schema that no longer exists. Staging first
 * means the run either lands completely or leaves the destination as it found it.
 * Renaming is not one atomic operation across the whole set, but every rename
 * happens after all the risky work (generating, creating directories, writing
 * bytes) has already succeeded, so it is the cheapest place to get the guarantee.
 *
 * A generated path that already exists is simply replaced. The writer keeps no
 * record of what it produced last time: an output directory is generated output,
 * and version control is where a user sees — and reverts — a replacement they did
 * not want. What the writer still guarantees is that `--build` only ever deletes
 * intermediate sources this run committed, so nothing that was already sitting in
 * the output directory is removed.
 */
export type OutputWriter = {
    /**
     * Stages one file. `relativePath` is relative to the writer's root and may
     * contain subdirectories; parent directories are created eagerly.
     */
    readonly stage: (relativePath: string, content: string) => Promise<void>;
    /** Moves every staged file to its final path and returns the committed paths. */
    readonly commit: () => Promise<string[]>;
    /** Deletes the staged temporaries; call this when the run fails before committing. */
    readonly discard: () => Promise<void>;
};
/**
 * Creates an {@link OutputWriter} rooted at `rootDir`.
 *
 * Still async with nothing to await: it read the previous run's manifest here
 * until that was removed, and every call site already awaits it. Keeping the
 * signature leaves room for setup that does need I/O.
 *
 * @param rootDir - Output root. Every write must resolve inside it.
 */
export declare const createOutputWriter: (rootDir: string) => Promise<OutputWriter>;