EnableLowerCamelCase causes Skiptoken to fail to generate on second page of query when using orderby desc

[jsangco]

Discussed in #1059

^{Originally posted by jsangco September 22, 2023}
Using Microsoft.AspNetCore.OData version 8.2.3, the framework will properly generate the skiptoken for the first API call, but it fails to generate a nextLink on subsequent calls when using a orderby=id desc query.

Here is an example of the output I see when executing the following queries with a max page size of 3 and 100 customers

> curl https://localhost:7187/odata/customers?orderby=id%20desc
{
  "value": [{"id": 100},{"id": 99},{"id": 98}],
  "@odata.nextLink": "https://localhost:7187/odata/customers?orderby=id%20desc&$skiptoken=id-97"
}

> curl https://localhost:7187/odata/customers?orderby=id%20desc&$skiptoken=id-97
{
  "value": [{"id": 97},{"id": 96},{"id": 95}],
}

Note: The second query does not contain the @odata.nextLink property.

This query was working in version 8.0.11, however, in that version, skipToken does not work with select queries.
Please advise.

[ElizabethOkerio]

@jsangco..This is what I've tried to repro the issue:
controller

        [HttpGet]
        [EnableQuery(PageSize = 3)]
        public IActionResult Get()
        {
            return Ok(_context.Products);
        }

https://localhost:44392/odata/Products?$orderby=Id%20desc

Response

{
  "@odata.context": "https://localhost:44392/odata/$metadata#Products",
  "value": [
    {
      "Id": 99
    },
    {
      "Id": 98
    },
    {
      "Id": 97
    }
  ],
  "@odata.nextLink": "https://localhost:44392/odata/Products?orderby=Id%20desc&$skiptoken=Id-97"
}

https://localhost:44392/odata/Products?orderby=Id%20desc&$skiptoken=Id-97

Response

{
  "@odata.context": "https://localhost:44392/odata/$metadata#Products",
  "value": [
    {
      "Id": 96
    },
    {
      "Id": 95
    },
    {
      "Id": 94
    }
  ],
  "@odata.nextLink": "https://localhost:44392/odata/Products?orderby=Id%20desc&$skiptoken=Id-94"
}

I seem to get the skiptoken on subsequent calls.Could it be possible that there's no more data to be fetched in the subsequent call in your case? Please share a repro to help us debug this.

[gathogojr]

@jsangco An attempt to reproduce the issue was unsuccessful. Kindly share with us a simple repro to help with troubleshooting

[gathogojr]

Hi @jsangco. Are you able to provide us with more details to help us troubleshoot the issue?

[jsangco]

Yes, I've started working on a cleaner way to reproduce the issue.

[jsangco]

Looks like the issue is caused by ODataConventionModelBuilderExtensions.EnableLowerCamelCase, and the issue does not exist in the previous 8.0.11 version of the assembly.

I've updated the title of the thread.

Code below will reproduce the issue:

// Program.cs
using Microsoft.AspNetCore.OData;
using Microsoft.OData.Edm;
using Microsoft.OData.ModelBuilder;
using SkipTokenFail;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddSwaggerGen();
builder.Services.AddControllers()
    .AddOData(options => 
    {
        options.EnableQueryFeatures();
        options.AddRouteComponents("v1", CreateEdmModel());
    });

static IEdmModel CreateEdmModel()
{
    var builder = new ODataConventionModelBuilder();
    builder.EnableLowerCamelCase(); // <-- This line causes skip token to fail; remove it and it will work.

    builder.EntitySet<Product>("products").EntityType
    .HasKey(e => e.Id)
    .Page(10, 10);

    return builder.GetEdmModel();
}

var app = builder.Build();
app.UseRouting();
app.MapControllers();

app.Run();

// ProductsController.cs
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.OData.Query;
using Microsoft.AspNetCore.OData.Routing.Controllers;

namespace SkipTokenFail;

[ApiController]
[Route("v1/products")]
public class ProductsController : ODataController
{
    [EnableQuery()]
    [HttpGet]
    public IQueryable<Product> Get()
    {
        var products = Enumerable.Range(0, 1000).Select(i => new Product() { Id = i }).AsQueryable();
        return products;
    }
}

public class Product
{
    public int Id { get; set; }
}

<!-- SkipTokenFail.csproj -->
<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <InvariantGlobalization>true</InvariantGlobalization>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.0-rc.1.23421.29" />
    <!-- The issue does not occur in version 8.0.11 -->
    <!-- <PackageReference Include="Microsoft.AspNetCore.OData" Version="8.0.11" /> -->
    <PackageReference Include="Microsoft.AspNetCore.OData" Version="8.2.3" />
    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
  </ItemGroup>

</Project>

[gathogojr]

@jsangco This issue was recently fixed in this pull request and should be in our next release.

If you can, kindly test against the nightly build at this location