[BUG] ITableEntity interface does not describe runtime requires (Timestamp set is actually needed)

[joelverhagen]

Describe the bug
As of version 12.0.0-beta.8 of Azure.Data.Tables, the property setter on Timestamp was removed from the interface. When querying for an entity type that doesn't have the setter implemented, an exception is thrown due to the missing setter. Presumably the reflection-ey code that materializes the entity is expecting to set the timestamp value returned in the HTTP response.

If the setter is added -- implementing Timestamp { get; set; } for a Timestamp { get; } interface -- the problem is resolved.

Expected behavior
I think the interface should represent what is actually needed by the TableClient.QueryAsync<T>(...) method. Either the setter should not be called if not present (a bit weird since it would be like a hidden feature to have the timestamp populated when implemented) or the setter should be included in the interface.

Actual behavior (include Exception or Stack Trace)

Unhandled exception. System.ArgumentException: Property set method not found.
   at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture)
   at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, Object[] index)
   at System.Reflection.PropertyInfo.SetValue(Object obj, Object value)
   at Azure.Data.Tables.DictionaryTableExtensions.<>c.<.cctor>b__8_12(PropertyInfo property, Object propertyValue, Object result)
   at Azure.Data.Tables.DictionaryTableExtensions.ToTableEntity[T](IDictionary`2 entity, PropertyInfo[] properties)
   at Azure.Data.Tables.DictionaryTableExtensions.ToTableEntityList[T](IReadOnlyList`1 entityList)
   at Azure.Data.Tables.TableClient.<>c__DisplayClass44_0`1.<<QueryAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Azure.Core.PageableHelpers.FuncAsyncPageable`1.AsPages(String continuationToken, Nullable`1 pageSizeHint)+MoveNext()
   at Azure.Core.PageableHelpers.FuncAsyncPageable`1.AsPages(String continuationToken, Nullable`1 pageSizeHint)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
   at Azure.AsyncPageable`1.GetAsyncEnumerator(CancellationToken cancellationToken)+MoveNext()
   at Azure.AsyncPageable`1.GetAsyncEnumerator(CancellationToken cancellationToken)+MoveNext()
   at Azure.AsyncPageable`1.GetAsyncEnumerator(CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
   at ConsoleApp1.Program.Main(String[] args) in C:\z\trash\2021-05-11\ConsoleApp1\ConsoleApp1\Program.cs:line 18
   at ConsoleApp1.Program.<Main>(String[] args)

To Reproduce

using Azure;
using Azure.Data.Tables;
using System;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var tableServiceClient = new TableServiceClient("UseDevelopmentStorage=true");
            var tableClient = tableServiceClient.GetTableClient("testissue21023");
            await tableClient.CreateIfNotExistsAsync();
            var entity = new TestEntity { PartitionKey = "pk", RowKey = "rk" };
            await tableClient.UpsertEntityAsync(entity, TableUpdateMode.Replace);

            await tableClient.QueryAsync<TestEntity>().GetAsyncEnumerator().MoveNextAsync();
        }
    }

    class TestEntity : ITableEntity
    {
        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public DateTimeOffset? Timestamp { get; }
        public ETag ETag { get; set; }
    }
}

Environment:

• Name and version of the Library package used: Azure.Data.Tables 12.0.0-beta.8
• Hosting platform or OS and .NET runtime version (dotnet --info output for .NET Core projects): Windows, .NET 5.0.300-preview.21228.15
• IDE and version : VS 16.10 preview

[jsquire]

Thank you for your feedback. Tagging and routing to the team member best able to assist.

[christothes]

Thanks @joelverhagen - I actually ran into this recently also and agree it is a bad experience. We initially removed it because the Timestamp value, if set, is ignored by the service. I'll get this fixed before the next release.