Function createCleanup

packages/mcp-client/src/connection.ts:448–493

(options: CleanupOptions)

 * Handles in-process servers, stderr listener removal, signal escalation, and client close.
 */
export function createCleanup(options: CleanupOptions): () => Promise<void> {
  const {
    client,
    transport,
    transportType,
    childPid,
    inProcessServer,
    stderrCleanup,
    logger,
    serverName,
  } = options

  return async () => {
    // In-process servers
    if (inProcessServer) {
      try {
        await inProcessServer.close()
      } catch (error) {
        logger.debug(
          `[${serverName}] Error closing in-process server: ${error}`,
        )
      }
      try {
        await client.close()
      } catch (error) {
        logger.debug(`[${serverName}] Error closing client: ${error}`)
      }
      return
    }

    // Remove stderr listener
    stderrCleanup?.removeHandler()

    // Signal escalation for stdio
    if (transportType === 'stdio' && childPid) {
      await terminateWithSignalEscalation(childPid, logger, serverName)
    }

    // Close the client connection (which also closes the transport)
    try {
      await client.close()
    } catch (error) {
      logger.debug(`[${serverName}] Error closing client: ${error}`)
    }
  }
}

// ============================================================================
// Connected server result builder