/**
 * What produced a baseline number. One consumer's `migrationWarnings` read 51 for eleven days over
 * an unchanged tree while the truth was 58: our own output truncation was cutting the report.
 * Evidence, never a floor.
 */
export type Instrument = {
    /** `null` for a counter that runs none (`lawLineCount` reads a file). */
    command: string | null;
    fingerprint: string;
    params: Record<string, unknown>;
    reads: Record<string, string>;
    version: string;
};
export type MeasurementIdentity = Instrument & {
    /** When the baseline was edited by hand since, the identity is unknown. */
    recordedFor: number;
    /**
     * The number this one overwrote, `null` for an adoption. A consumer who corrects a truncated 51
     * up to 58 and meets a build still reading 51 would bank it as "improved -7"; keeping the
     * overwritten number makes that recoverable.
     */
    replaced: number | null;
};
type RecordedIdentity = Omit<MeasurementIdentity, 'fingerprint' | 'params' | 'reads'> & {
    fingerprint?: string;
    params?: Record<string, unknown>;
    reads?: Record<string, string>;
};
export type IdentityFile = {
    entries: Record<string, unknown>;
    unreadable: string | null;
};
export type IdentityVerdict = {
    differs: string[];
    verdict: 'changed';
    was: RecordedIdentity;
} | {
    verdict: 'same';
} | {
    verdict: 'unchecked';
} | {
    reason: string;
    verdict: 'unknown';
};
export declare const identityPathFor: (baselinePath: string) => string;
export declare const readIdentities: (path: string) => IdentityFile;
export declare const writeIdentities: (path: string, recorded: Record<string, MeasurementIdentity>) => void;
export declare const paramsOf: (entry: Record<string, unknown>) => Record<string, unknown>;
export declare const NEVER_READ: Set<string>;
export declare const digestsOf: (cwd: string, patterns: readonly string[]) => Record<string, string>;
export declare const compareIdentity: ({ baseline, file, key, now }: {
    baseline: number;
    file: IdentityFile;
    key: string;
    now: Instrument;
}) => IdentityVerdict;
export type Direction = 'grew' | 'shrank';
export declare const explainIdentity: ({ direction, verdict }: {
    direction: Direction;
    verdict: IdentityVerdict;
}) => string;
export {};