export type PatchedFile = {
    /** Path of the patched file relative to the package root. */
    relativePath: string;
    source: string;
};
/**
 * Reads every file a patch touches and returns their patched source. Nothing is
 * written to disk — the results are handed to the module loader hook, which
 * compiles them in place of the originals.
 *
 * Returns `null` when a hunk does not apply, which is the signal that upstream
 * has moved and the patch must be regenerated.
 */
export declare function readPatchedFiles(packageDir: string, patchFilePath: string): PatchedFile[] | null;
/**
 * True when every hunk reverses cleanly, meaning the patch is already present —
 * the equivalent of `git apply --reverse --check`. Someone may have applied the
 * same diff through their own package manager, which is a supported outcome
 * rather than a conflict.
 */
export declare function isPatchApplied(packageDir: string, patchFilePath: string): boolean;
/**
 * Applies whichever patch targets `absolutePath`, if any, returning the patched
 * source or `null` when the file is not a patch target.
 *
 * This is the loader-agnostic half of the system: Node's require hook and the
 * Jest transformer both funnel through it, so a patch means the same thing in
 * production and under test.
 */
export declare function patchSourceForPath(absolutePath: string, source: string): string | null;