Function verifyChannelStillPrivate

server/src/slack/client.ts:427–454

(
  channelId: string,
)

 * #2735
 */
export async function verifyChannelStillPrivate(
  channelId: string,
): Promise<ChannelPrivacyState> {
  const info = await getChannelInfo(channelId);
  if (!info) {
    logger.warn(
      { channelId, event: 'channel_privacy_verify_unavailable' },
      'Could not verify Slack channel privacy state — caller must decide whether to proceed',
    );
    return 'unknown';
  }
  if (info.is_private !== true) {
    // Drop the stale cache entry so a rapid re-privatize by an admin
    // is picked up on the very next send rather than after the remaining
    // TTL. `getChannelInfo`'s next call will re-fetch.
    channelCache.delete(channelId);
    logger.warn(
      {
        channelId,
        channelName: info.name,
        event: 'channel_privacy_drift',
      },
      'Configured Slack channel is no longer private — refusing to post sensitive content. Admin action required to re-privatize or unlink.',
    );
    return 'public';
  }
  return 'private';
}

/**
 * Result of `verifyChannelPrivacyForWrite` — the write-time gate that