Documents previously indexed with TimeSpan as string cause UnexpectedElasticsearchClientException.

[jonyadamit]

As a consequence of #1705 , types indexed prior to 2c3abf6 that have TimeSpan/TimeSpan? properties throw the following exception upon retrieval:

Exception thrown: 'Elasticsearch.Net.UnexpectedElasticsearchClientException' in mscorlib.dll

Additional information: Cannot convert token of type String to System.Nullable`1[System.TimeSpan].

   at Nest.TimeSpanConverter.ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer) in C:\users\russ\source\elasticsearch-net\src\Nest\CommonAbstractions\SerializationBehavior\GenericJsonConverters\TimeSpanConverter.cs:line 30
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.DeserializeConvertable(JsonConverter converter, JsonReader reader, Type objectType, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonSerializer.Deserialize(JsonReader reader, Type objectType)
   at Nest.JsonNetSerializer.Deserialize[T](Stream stream) in C:\users\russ\source\elasticsearch-net\src\Nest\CommonAbstractions\SerializationBehavior\JsonNetSerializer.cs:line 90
   at Nest.JsonNetSerializer.DeserializeAsync[T](Stream stream, CancellationToken cancellationToken) in C:\users\russ\source\elasticsearch-net\src\Nest\CommonAbstractions\SerializationBehavior\JsonNetSerializer.cs:line 98
   at Elasticsearch.Net.ResponseBuilder`1.<SetBodyAsync>d__19.MoveNext() in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Transport\Pipeline\ResponseBuilder.cs:line 97
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Elasticsearch.Net.ResponseBuilder`1.<ToResponseAsync>d__16.MoveNext() in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Transport\Pipeline\ResponseBuilder.cs:line 39
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Elasticsearch.Net.HttpConnection.<RequestAsync>d__7`1.MoveNext() in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Connection\HttpConnection.cs:line 183
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Elasticsearch.Net.RequestPipeline.<CallElasticsearchAsync>d__66`1.MoveNext() in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Transport\Pipeline\RequestPipeline.cs:line 409
   at Elasticsearch.Net.ExceptionExtensions.RethrowKeepingStackTrace(Exception exception) in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Extensions\ExceptionExtensions.cs:line 18
   at Elasticsearch.Net.RequestPipeline.<CallElasticsearchAsync>d__66`1.MoveNext() in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Transport\Pipeline\RequestPipeline.cs:line 420
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Elasticsearch.Net.Transport`1.<RequestAsync>d__15`1.MoveNext() in C:\users\russ\source\elasticsearch-net\src\Elasticsearch.Net\Transport\Transport.cs:line 128

[russcam]

Hey @jonyadamit,

This is a result of inferring TimeSpan to be long that went in as part of Nest 2.x.

I've made a change in ba0ea0a to be able to deserialize existing TimeSpan properties indexed as string correctly, however in order to index new documents with the TimeSpan property as a string would require a converter, either by deriving from JsonNetSerializer and overriding ContractConverters or by attributing the property with [JsonConverter(typeof(ConverterTypeName))]. A example of a converter for serializing/deserializing string values for TimeSpan

public class StringTimeSpanConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        if (value == null)
            writer.WriteNull();
        else
        {
            var timeSpan = (TimeSpan)value;
            writer.WriteValue(timeSpan.ToString());
        }
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.Null)
        {
            if (!objectType.IsGeneric() || objectType.GetGenericTypeDefinition() != typeof(Nullable<>))
                throw new JsonSerializationException($"Cannot convert null value to {objectType}.");

            return null;
        }
        if (reader.TokenType == JsonToken.String)
        {
            return TimeSpan.Parse((string)reader.Value);
        }

        throw new JsonSerializationException($"Cannot convert token of type {reader.TokenType} to {objectType}.");
    }

    public override bool CanConvert(Type objectType) => objectType == typeof(TimeSpan) || objectType == typeof(TimeSpan?);
}

[jonyadamit]

Hey @russcam, maybe this should be noted on the release breaking changes?
So that people would be better prepared for migration.

Closing this as it is addressed by ba0ea0a.

[russcam]

@jonyadamit yes to adding to breaking changes; I'll add it now 👍