Checked context breaks Linq-to-CQL

[BrunoJuchli]

Symptom

When using a checked context (we enabled it by default for the whole solution) some of our queries start to fail with errors like:

System.InvalidOperationException : variable 'x' of type 'CounterEntryEntity`1[ElectricActiveEnergyTwoTariffsCount]' referenced from scope '', but it is not defined
at System.Linq.Expressions.Compiler.VariableBinder.Reference(ParameterExpression node, VariableStorageKind storage)
at System.Linq.Expressions.Compiler.VariableBinder.VisitParameter(ParameterExpression node)
at System.Linq.Expressions.ExpressionVisitor.VisitMember(MemberExpression node)
at System.Linq.Expressions.Compiler.VariableBinder.VisitUnary(UnaryExpression node)
at System.Linq.Expressions.ExpressionVisitor.Visit(ReadOnlyCollection`1 nodes)
at System.Linq.Expressions.Compiler.VariableBinder.VisitLambda[T](Expression`1 node)
at System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression lambda)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitUnary(UnaryExpression node)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitBinary(BinaryExpression node)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitBinary(BinaryExpression node)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitBinary(BinaryExpression node)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitBinary(BinaryExpression node)
at System.Linq.Expressions.ExpressionVisitor.VisitLambda[T](Expression`1 node)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitLambda[T](Expression`1 node)
at Cassandra.Data.Linq.CqlExpressionVisitor.VisitMethodCall(MethodCallExpression node)
at Cassandra.Data.Linq.CqlExpressionVisitor.GetSelect(Expression expression, Object[]& values)
at Cassandra.Data.Linq.CqlQuery`1.ExecutePagedAsync(String executionProfile)

Analysis

Given a table entity like:

public class Table
{
    public short Short { get; init; }
}

And a query where filtering like:

short s = 3821;

.Where(t => t.Short == s);

Depending on whether a checked or unchecked context is used, the following expression is generated:

• ... (ConvertChecked(t.Short, Int32) == ConvertChecked(value(<generatedclass>.s, Int32)))
• ... (Convert(t.Short, Int32) == Convert(value(<generatedclass>.s, Int32)))

Proposed Solution

There's four usages of ExpressionType.Convert in the solution (3 in CqlExpressionVisitor and 1 in Mapping\Map.cs.
All perform comparisons like node.NodeType == ExpressionType.Convert
I suggest it should be replaced with

(node.NodeType == ExpressionType.Convert || node.NodeType == ExpressionType.ConvertChecked)

Workaround

Instead of writing

.Where(t => t.Short == s);

write

.Where(unchecked(t => t.Short == s));

Reproduce

I wanted to provide a PR with a reproduction. Unfortunately I fail to compile the solution (both from dotnet CLI and within rider, I get nuget restore errors for Apps.Metrics.Concurrency and I also think there may be some setup steps necessary to get the right target frameworks in the projects, but I haven't found any documentation / the documentation link to the wiki is dead).

However, adding

<PropertyGroup>
  <CheckForOverflowUnderflow>true</CheckForOverflowUnderflow>
</PropertyGroup>

to the test projects might already cause some of the tests to fail.

if not, try a scenario as shown in Analysis, where you filter for a Short value, and put the predicate into a checked context:

short s = 3802;

.Where(checked(t => t.Short == s));

[joao-r-reis]

I wanted to provide a PR with a reproduction. Unfortunately I fail to compile the solution (both from dotnet CLI and within rider, I get nuget restore errors for Apps.Metrics.Concurrency and I also think there may be some setup steps necessary to get the right target frameworks in the projects, but I haven't found any documentation / the documentation link to the wiki is dead).

Hi, there's some information on CONTRIBUTING.md if you want to build and run tests locally but dotnet restore failing is not a known issue so I'm not sure what's happening. By default without setting any environment variables the default target frameworks would be used and the solution should build correctly...

[joao-r-reis]

It might be related to the fact that App.Metrics.Concurrency is marked as legacy on nuget.org, but there should be a way to bypass any errors that you might be seeing due to that

[joao-r-reis]

If you're using .NET 9, you can try reverting to the legacy restore algorithm.

[BrunoJuchli]

Thank you for getting back to me.
So I investigated some more. It looks like it is a local "on my machine only" problem. I've cloned another repository (serilog) and attempted to dotnet restore there, and it failed. Probably my nuget config is messed up, somehow.

---

For completeness sake, the restore error I got was:

Cassandra.Tests.csproj : error NU1301:
Failed to retrieve information about 'App.Metrics.Concurrency' from remote source 'https://nuget.pkg.github.com/Fi
ndPackagesById()?id='App.Metrics.Concurrency'&semVerLevel=2.0.0'.
Response status code does not indicate success: 405 (Method Not Allowed).

I noticed that I didn't have .net 8 sdk installed anymore. So I installed its latest version and added a global.json file pinning the sdk to this version.
After performing clean, a restore fails with the same errors - plus an additional one:

Cassandra.IntegrationTests.csproj : error NU1301:
Failed to retrieve information about 'System.Diagnostics.DiagnosticSource' from remote source 'https://nuget.pkg.githu
b.com/FindPackagesById()?id='System.Diagnostics.DiagnosticSource'&semVerLevel=2.0.0'. [C:\Development\cassandra-csharp-
driver\src\Cassandra.sln]

I've checked, and this package is not deprecated.

using dotnet restore -p:RestoreUseLegacyDependencyResolver=true doesn't fix the issue, either on .net 8 sdk or .net 10 sdk.
If I do legacy dependency resolution with .net 10 sdk, i get the System.Diagnostics.DiagnosticsSource error, too.

Note

With the serilog repo I noticed that they include a nuget.config file. Deleting it fixed the issue for serilog, now I can restore it w/o a problem.
dotnet nuget config get all --show-path helped me identify which config / -files exist
for csharp-driver there is no extra config file, still it doens't work...

[BrunoJuchli]

So I finally found out the root cause for my problem; just in case someone has similar issues and ends up here:
I had a custom nuget package source in my users (global) NuGet.Config.
It used https://nuget.pkg.github.com (without a namespace) which only seems to support protocol version 3.
After changing it to

<add key="yourkey" value="https://nuget.pkg.github.com/yournamespace/index.json" protocolVersion="3" />

everything works.

[joao-r-reis]

Oh wow I wonder why that caused it to fail for specific packages not everything, weird.

Coming back to the C# driver issue itself, this seems like one of the things that should be included in a potential future release of the driver that aims to improve driver support of modern .NET versions.

I've been working more on the Go driver than C# these days but we're always open to contributions from the community.