Handle unknown search result kinds without throwing #226

src/CompaniesHouse/JsonConverters/SearchItemConverter.cs

@@ -28,7 +28,7 @@ public override SearchItem Read(ref Utf8JsonReader reader, Type typeToConvert, J
                 "searchresults#company" => root.Deserialize<Company>(options)!,
                 "searchresults#officer" => root.Deserialize<Officer>(options)!,
                 "searchresults#disqualified-officer" => root.Deserialize<DisqualifiedOfficer>(options)!,
-                _ => throw new NotImplementedException($"Unknown search item kind \"{kind}\".")
+                _ => root.Deserialize<UnknownSearchItem>(options)!
             };
 
             return item;

src/CompaniesHouse/Response/Search/UnknownSearchItem.cs

@@ -0,0 +1,13 @@
+using System.Text.Json.Serialization;
+
+namespace CompaniesHouse.Response.Search
+{
+    public class UnknownSearchItem : SearchItem
+    {
+        [JsonPropertyName("title")]
+        public string? Title { get; set; }
+
+        [JsonPropertyName("description")]
+        public string? Description { get; set; }
+    }
+}

tests/CompaniesHouse.ScenarioTests/SearchResponseDeserializationScenarioTests.cs

@@ -27,6 +27,17 @@ public void SearchAllPayload_DeserializesMixedCompanyAndOfficerItems()
             allItems[2].ShouldBeOfType<CompaniesHouse.Response.Search.OfficerSearch.Officer>();
         }
 
+        [Fact]
+        public void SearchAllPayload_DeserializesUnknownKindAsGenericSearchItem()
+        {
+            var payload = JsonSerializer.Deserialize<AllSearch>(UnknownKindSearchAllJson, CompaniesHouseJsonSerializerOptions.Default);
+
+            payload.ShouldNotBeNull();
+            var item = (payload.Items ?? [])[0];
+            item.Kind.ShouldBe("searchresults#new-kind");
+            item.ShouldBeOfType<UnknownSearchItem>();
+        }
+
         [Fact]
         public void CompanySearchPayload_DeserializesAddressSnippetAndExternalRegistrationNumber()
         {
@@ -163,6 +174,24 @@ public void DissolvedCompaniesPayload_DeserializesSearchTypeSpecificOptionalFiel
             }
             """;
 
+        private const string UnknownKindSearchAllJson = """
+            {
+              "items": [
+                {
+                  "kind": "searchresults#new-kind",
+                  "title": "NEW TYPE ITEM",
+                  "description": "Fallback for an unknown search item kind",
+                  "links": { "self": "/search/unknown" }
+                }
+              ],
+              "kind": "search#all",
+              "page_number": 1,
+              "items_per_page": 1,
+              "total_results": 1,
+              "start_index": 0
+            }
+            """;
+
         private const string CompanySearchJson = """
             {
               "items": [