Passing empty objectId to DeleteObject deletes the ENTIRE index, configuration, settings.

[wsturges]

Passing an empty string as objectId to the SearchClient.DeleteObject deletes the entire index (not just a record, but the entire index, configuration, settings, etc). Example mySearchClient.DeleteObjectAsync("my_index", "")

algoliasearch-client-csharp/algoliasearch/Clients/SearchClient.cs

Line 6654 in 32ecd39

if (objectID == null)

1. The null check is the only guard (SearchClient.cs:6654):
   if (objectID == null)
   throw new ArgumentException("Parameter objectID is required when calling DeleteObject.");
   An empty string passes this check.

2. ParameterToString("") returns "" (QueryStringHelper.cs:32-53)
   — the default branch hits Convert.ToString("", ...) which is just
   "". No empty-string handling.

3. The path template gets a literal empty substitution
   (HttpTransport.cs:399):
   path = path.Replace("{" + parameter.Key + "}",
   Uri.EscapeDataString(parameter.Value));
   Template /1/indexes/{indexName}/{objectID} becomes
   /1/indexes/myIndex/ (trailing slash, empty segment).
   Uri.EscapeDataString("") is "", so no protection there either.

4. What Algolia's API does with DELETE /1/indexes/myIndex/ — the
   delete-index endpoint is DELETE /1/indexes/{indexName} (you can
   see it just above at SearchClient.cs:6628). Algolia's gateway
   normalizes trailing slashes, so DELETE /1/indexes/myIndex/ is
   treated as DELETE /1/indexes/myIndex — which deletes the entire
   index (records + settings). It is not the same as "clear index"
   (POST /1/indexes/{name}/clear); a delete is more destructive
   because it also drops settings, replicas config, etc.

Conclusion: Calling DeleteObject(indexName, "") with the C# SDK
at this commit will send a request that Algolia routes to the
delete-index endpoint and wipes the whole index. The SDK does not
validate against empty, and the URL builder happily produces the
trailing-slash path. Given your recent commits (e996d8f
Implement null/empty item_id check, e24a68c Don't do Algolia
deletes), it sounds like you've already homed in on this — the
null/empty guard at the call site is the right fix; do not rely
on the SDK to catch it.

[wsturges]

Possible easy fix for this:

FROM
if (objectID == null)
throw new ArgumentException("Parameter objectID is required when calling DeleteObject.");
TO
if (string.IsNullOrWhitespace(objectID))
throw new ArgumentException("Parameter objectID is required when calling DeleteObject.");