Function findPreviousReleaseBenchmark

scripts/compare-release-benchmarks.ts:100–131

(version: string, directory = releaseBenchmarkDir())

/** Find the latest stable benchmark snapshot lower than the release candidate version. */
export function findPreviousReleaseBenchmark(version: string, directory = releaseBenchmarkDir()) {
  const current = parseReleaseVersion(version);
  if (!existsSync(directory)) {
    return undefined;
  }

  const candidates = readdirSync(directory)
    .map((fileName) => {
      const match = BENCHMARK_FILE_PATTERN.exec(fileName);
      if (!match) {
        return undefined;
      }

      const candidateVersion = parseReleaseVersion(match[1]!);
      if (candidateVersion.prerelease) {
        return undefined;
      }

      if (compareReleaseVersions(candidateVersion.raw, current.raw) >= 0) {
        return undefined;
      }

      return {
        version: candidateVersion.raw,
        path: path.join(directory, fileName),
      };
    })
    .filter((candidate): candidate is { version: string; path: string } => Boolean(candidate))
    .sort((left, right) => compareReleaseVersions(right.version, left.version));

  return candidates[0];
}

/** Read and lightly validate one benchmark JSON file. */
export async function loadBenchmarkRun(filePath: string): Promise<BenchmarkRunResult> {