Function createCommandPrefixExtractor

src/utils/shell/prefix.ts:92–126

(config: PrefixExtractorConfig)

 * @returns A memoized async function that extracts command prefixes
 */
export function createCommandPrefixExtractor(config: PrefixExtractorConfig) {
  const { toolName, policySpec, eventName, querySource, preCheck } = config

  const memoized = memoizeWithLRU(
    (
      command: string,
      abortSignal: AbortSignal,
      isNonInteractiveSession: boolean,
    ): Promise<CommandPrefixResult | null> => {
      const promise = getCommandPrefixImpl(
        command,
        abortSignal,
        isNonInteractiveSession,
        toolName,
        policySpec,
        eventName,
        querySource,
        preCheck,
      )
      // Evict on rejection so aborted calls don't poison future turns.
      // Identity guard: after LRU eviction, a newer promise may occupy
      // this key; a stale rejection must not delete it.
      promise.catch(() => {
        if (memoized.cache.get(command) === promise) {
          memoized.cache.delete(command)
        }
      })
      return promise
    },
    command => command, // memoize by command only
    200,
  )

  return memoized
}

/**
 * Creates a memoized function to get prefixes for compound commands with subcommands.