C# bindings for views

[rekhoff]

Description of Changes

Updates C# bindings to allow module authors to define Views and AnonymousViews using the pattern:

[SpacetimeDB.View]
public static ExampleData? GetExampleDataById(ViewContext ctx, uint id)
{
    return ctx.Db.ExampleData.Id.Find(id);
}
	
[SpacetimeDB.View]
public static ExampleData? GetAnonymousExampleDataById(AnonymousViewContext ctx, uint id)
{
    return ctx.Db.ExampleData.Id.Find(id);
}

During publishing of a C# module, the views data will be converted into RawViewDefV9

API and ABI breaking changes

No known breaking changes

Expected complexity level and risk

2

Testing

• Locally tested locally adding the above sample pattern to the sdks\csharp\examples~\regression-tests\server test and performing a dotnet build and a spacetime publish test, both of which succeeded.

[github-actions]

Some missing or dangling .meta found. Fix commits are needed.

Status	File
Not committed	src/SpacetimeDB/ClientApi/CallProcedure.g.cs.meta
Not committed	src/SpacetimeDB/ClientApi/ProcedureResult.g.cs.meta
Not committed	src/SpacetimeDB/ClientApi/ProcedureStatus.g.cs.meta

[joshua-spacetime]

@JasonAtClockwork could you also disable parameters for now? We can re-enable once we have sql support for them.

[JasonAtClockwork]

@JasonAtClockwork could you also disable parameters for now? We can re-enable once we have sql support for them.

Added another temporary error that will block arguments beyond the context:
\sdks\csharp\examples~\regression-tests\server\Lib.cs(18,5): error STDB0023: View 'GetExampleDataById' must have no arguments beyond the context. This is a temporary limitation.

[JasonAtClockwork]

@JasonAtClockwork Can you try to copy over some of the negative compile tests that are in bindings/tests/ui/views.rs into bindings-csharp/Codegen.Tests/fixtures/diag/Lib.cs? You don't have to copy all of them over. I mainly just want to test that compilation fails if we try to access the wrong methods on ViewContext and AnonymousViewContext, or return the wrong type.

Copied most of the tests and fixed an issue with missing return type checks in the codegen

[joshua-spacetime]

I reviewed the tests and the runtime, but I did not review the codegen. I feel confident approving based on the test coverage, although I will outline a few more tests that would be useful to add before merging:

1. Can't obtain an identity from an AnonymousViewContext
2. Can't call Iter() on a table handle obtained from a read only context
3. Can't call mutations like delete on an index handle obtained from a read only context

[JasonAtClockwork]

I reviewed the tests and the runtime, but I did not review the codegen. I feel confident approving based on the test coverage, although I will outline a few more tests that would be useful to add before merging:

1. Can't obtain an identity from an AnonymousViewContext
2. Can't call Iter() on a table handle obtained from a read only context
3. Can't call mutations like delete on an index handle obtained from a read only context

Turns out Iter() was available on a ReadOnly table, and Delete() was available on a ReadOnly Index but they're now fixed. I've also added the three new tests so it might be another look before we merge just in case.

[joshua-spacetime]

Looks great! Thanks @JasonAtClockwork

[cloutiertyler]

All tests are passing. I'm force merging this one.