Function loadStatsCache

source code/utils/statsCache.ts:149–210

()

 * Returns an empty cache if the file doesn't exist or is invalid.
 */
export async function loadStatsCache(): Promise<PersistedStatsCache> {
  const fs = getFsImplementation()
  const cachePath = getStatsCachePath()

  try {
    const content = await fs.readFile(cachePath, { encoding: 'utf-8' })
    const parsed = jsonParse(content) as PersistedStatsCache

    // Validate version
    if (parsed.version !== STATS_CACHE_VERSION) {
      const migrated = migrateStatsCache(parsed)
      if (!migrated) {
        logForDebugging(
          `Stats cache version ${parsed.version} not migratable (expected ${STATS_CACHE_VERSION}), returning empty cache`,
        )
        return getEmptyCache()
      }
      logForDebugging(
        `Migrated stats cache from v${parsed.version} to v${STATS_CACHE_VERSION}`,
      )
      // Persist migration so we don't re-migrate on every load.
      // aggregateClaudeCodeStats() skips its save when lastComputedDate is
      // already current, so without this the on-disk file stays at the old
      // version indefinitely.
      await saveStatsCache(migrated)
      if (feature('SHOT_STATS') && !migrated.shotDistribution) {
        logForDebugging(
          'Migrated stats cache missing shotDistribution, forcing recomputation',
        )
        return getEmptyCache()
      }
      return migrated
    }

    // Basic validation
    if (
      !Array.isArray(parsed.dailyActivity) ||
      !Array.isArray(parsed.dailyModelTokens) ||
      typeof parsed.totalSessions !== 'number' ||
      typeof parsed.totalMessages !== 'number'
    ) {
      logForDebugging(
        'Stats cache has invalid structure, returning empty cache',
      )
      return getEmptyCache()
    }

    // If SHOT_STATS is enabled but cache doesn't have shotDistribution,
    // force full recomputation to get historical shot data
    if (feature('SHOT_STATS') && !parsed.shotDistribution) {
      logForDebugging(
        'Stats cache missing shotDistribution, forcing recomputation',
      )
      return getEmptyCache()
    }

    return parsed
  } catch (error) {