public void Setup() { var enumerableConverter = new EnumerableConverter <ItemType, JsonStringEnumConverter>(); using var ms = new MemoryStream(); using (var writer = new Utf8JsonWriter(ms)) { writer.WriteStartArray(); writer.WriteStringValue("Unknown"); writer.WriteStringValue("Address"); writer.WriteEndArray(); } var json = System.Text.Encoding.UTF8.GetString(ms.ToArray()); var reader = new Utf8JsonReader(ms.ToArray()); reader.Read(); _result = enumerableConverter.Read(ref reader, typeof(IEnumerable <ItemType>), new JsonSerializerOptions()); }