src/lib/perf/measure.ts

Linked repository file from this build.

import { gzipSync } from "node:zlib";
import type { StoredReview } from "@/features/reviews/review-store";
import type { CatalogReview } from "@/features/catalog/query";
import type { SnapReview } from "@/programs/snap-negative/types";
import { fiscalYear, reviewKey } from "@/features/reviews/review-key";

/** JSON byte length of the value the browser would parse. */
export function jsonBytes(value: unknown): number {
  return Buffer.byteLength(JSON.stringify(value));
}

/** Local gzip estimate; actual HTTP compression is measured by the browser suite. */
export function gzipBytes(value: unknown): number {
  return gzipSync(Buffer.from(JSON.stringify(value))).byteLength;
}

/** Median wall time after one warmup call. Timing tests use this to ignore the first compile. */
export function medianMs(work: () => void, runs = 5): number {
  work();
  const samples: number[] = [];
  for (let index = 0; index < runs; index++) {
    const started = performance.now();
    work();
    samples.push(performance.now() - started);
  }
  samples.sort((left, right) => left - right);
  return samples[Math.floor(samples.length / 2)]!;
}

export async function medianAsyncMs(work: () => Promise<void>, runs = 3): Promise<number> {
  await work();
  const samples: number[] = [];
  for (let index = 0; index < runs; index++) {
    const started = performance.now();
    await work();
    samples.push(performance.now() - started);
  }
  samples.sort((left, right) => left - right);
  return samples[Math.floor(samples.length / 2)]!;
}

/** Wire shape of a single workspace response. */
export function storedReview(review: SnapReview): StoredReview {
  return {
    review,
    version: 1,
    requestId: review.reviewNumber,
    actor: { name: "Seed", role: "examiner" },
    savedAt: "2026-09-08T12:00:00.000Z",
  };
}

/** Wire shape of one /api/catalog page. Catalog already uses this projection in production. */
export function catalogPage(reviews: SnapReview[]): CatalogReview[] {
  return reviews.slice(0, 10).map((review) => ({
    reviewNumber: review.reviewNumber,
    reviewKey: reviewKey(review),
    fiscalYear: fiscalYear(review.sampleMonth),
    clientName: review.clientName,
    caseNumber: review.caseNumber,
    examiner: review.examiner,
    state: review.state,
    outcome: review.outcome,
    updatedAt: "2026-09-08T12:00:00.000Z",
    routedBy: review.examiner,
    unread: false,
    flagged: false,
  }));
}