feat(clients): add helper to check if an index exists (generated)

algolia/api-clients-automation#3646

Co-authored-by: algolia-bot <accounts+algolia-api-client-bot@algolia.com>
Co-authored-by: Pierre Millot <pierre.millot@algolia.com>
Co-authored-by: Thomas Raffray <Fluf22@users.noreply.github.com>

Sources/Search/Extra/SearchClientExtension.swift

@@ -541,7 +541,7 @@ public extension SearchClient {
         batchSize: Int = 1000,
         requestOptions: RequestOptions? = nil
     ) async throws -> ReplaceAllObjectsResponse {
-        let tmpIndexName = try "\(indexName)_tmp_\(Int.random(in: 1_000_000 ..< 10_000_000))"
+        let tmpIndexName = "\(indexName)_tmp_\(Int.random(in: 1_000_000 ..< 10_000_000))"
 
         var copyOperationResponse = try await operationIndex(
             indexName: indexName,
@@ -627,4 +627,14 @@ public extension SearchClient {
 
         return timestampDate.timeIntervalSince1970 - Date().timeIntervalSince1970
     }
+
+    func indexExists(indexName: String) async throws -> Bool {
+        do {
+            _ = try await self.getSettings(indexName: indexName)
+        } catch let AlgoliaError.httpError(error) where error.statusCode == 404 {
+            return false
+        }
+
+        return true
+    }
 }