/** A git read the scan needs could not be completed. Thrown, never returned:
 *  the alternative is an empty file list that reads as "nothing changed". */
export declare class GitReadFailedError extends Error {
    readonly code = "FILE_SIZE_GIT_READ_FAILED";
    constructor(what: string, projectRoot: string, detail: string);
}
export type ChangedFiles = {
    /** Paths to measure in the working tree: Added/Modified entries plus rename
     *  targets. Deletions are omitted — they have no body to measure. */
    paths: string[];
    /** The path `file`'s baseline size must be read from: itself, or the name it
     *  had at `baseRef` before a rename. */
    baselinePathFor(file: string): string;
};
/**
 * One git enumeration for both readers that need the change set: the declared-
 * type rule judges `changedPaths` (deletions included), and the size scan
 * measures `changedFiles` (the A/M/R/untracked subset). Two spawns total,
 * `git diff` + `git ls-files`, never one pair per reader.
 */
export type GitChangeSet = {
    changedPaths: string[];
    changedFiles: ChangedFiles;
};
export declare function readGitChangeSet(projectRoot: string, baseRef: string, only?: readonly string[]): GitChangeSet;
/**
 * The measurable subset alone. Kept as the size scan's entry point; the
 * transition gate calls `readGitChangeSet` so the type rule shares the read.
 */
export declare function readChangedFiles(projectRoot: string, baseRef: string, only?: readonly string[]): ChangedFiles;
/** The file's raw-line count AT `baseRef`, or `null` when the ref has no such
 *  path — i.e. the change ADDED the file and it is over the cap by creation. */
export declare function readBaseLineCount(projectRoot: string, baseRef: string, file: string): number | null;