Function copyPluginToVersionedCache

src/utils/plugins/pluginLoader.ts:365–465

(
  sourcePath: string,
  pluginId: string,
  version: string,
  entry?: PluginMarketplaceEntry,
  marketplaceDir?: string,
)

 * @throws Error if the destination directory is empty after copy
 */
export async function copyPluginToVersionedCache(
  sourcePath: string,
  pluginId: string,
  version: string,
  entry?: PluginMarketplaceEntry,
  marketplaceDir?: string,
): Promise<string> {
  // When zip cache is enabled, the canonical format is a ZIP file
  const zipCacheMode = isPluginZipCacheEnabled()
  const cachePath = getVersionedCachePath(pluginId, version)
  const zipPath = getVersionedZipCachePath(pluginId, version)

  // If cache already exists (directory or ZIP), return it
  if (zipCacheMode) {
    if (await pathExists(zipPath)) {
      logForDebugging(
        `Plugin ${pluginId} version ${version} already cached at ${zipPath}`,
      )
      return zipPath
    }
  } else if (await pathExists(cachePath)) {
    const entries = await readdir(cachePath)
    if (entries.length > 0) {
      logForDebugging(
        `Plugin ${pluginId} version ${version} already cached at ${cachePath}`,
      )
      return cachePath
    }
    // Directory exists but is empty, remove it so we can recreate with content
    logForDebugging(
      `Removing empty cache directory for ${pluginId} at ${cachePath}`,
    )
    await rmdir(cachePath)
  }

  // Seed cache hit — return seed path in place (read-only, no copy).
  // Callers handle both directory and .zip paths; this returns a directory.
  const seedPath = await probeSeedCache(pluginId, version)
  if (seedPath) {
    logForDebugging(
      `Using seed cache for ${pluginId}@${version} at ${seedPath}`,
    )
    return seedPath
  }

  // Create parent directories
  await getFsImplementation().mkdir(dirname(cachePath))

  // For local plugins: copy entry.source directory (the single source of truth)
  // For remote plugins: marketplaceDir is undefined, fall back to copying sourcePath
  if (entry && typeof entry.source === 'string' && marketplaceDir) {
    const sourceDir = validatePathWithinBase(marketplaceDir, entry.source)

    logForDebugging(
      `Copying source directory ${entry.source} for plugin ${pluginId}`,
    )
    try {
      await copyDir(sourceDir, cachePath)