/** Normalized: 1.0 = linear, ~step = quadratic. Start loose, calibrate from data. */
export declare const GROWTH_BOUND = 2;
export declare const WARMUP = 2;
export declare const RUNS = 7;
/** Median ms over `runs` timed calls after `warmup` untimed ones. For the
 *  absolute smoke checks; growthFactor times differently (a nested median
 *  would defeat its interleave). */
export declare function measureMs(fn: () => unknown, opts?: {
    warmup?: number;
    runs?: number;
}): number;
/**
 * Normalized growth: 1.0 = linear, ~step = quadratic. `build(n)` does untimed
 * setup and returns the timed closure.
 *
 * The schedule is load-bearing: warm both sizes first, one timing per size per
 * round, and alternate the within-round order. Interleaving cancels random
 * noise; alternating also cancels monotonic drift (a fixed order would bias the
 * always-later size every round, which a median can't remove).
 */
export declare function growthFactor(build: (n: number) => () => unknown, small: number, large: number, opts?: {
    rounds?: number;
    warmup?: number;
}): number;
/** Record, then gate: with PERF_ENFORCE unset a breach only logs (informational);
 *  set, it throws. Tests never touch the env, so the flip to gating is one line. */
export declare function expectPerf(label: string, actual: number, bound: number): void;
/** Writes `source` to a fresh unique temp path so the process-wide parse cache
 *  (keyed on path) always misses, with content fixed so the workload stays
 *  constant. Only the file-based compile/build tests need this. */
export declare function cacheFreePath(source: string, ext?: string): string;