`Optimize-DbContext` Does Not Fully Qualify Types, Resulting in Compile Errors

[Mike-E-angelo]

File a bug

When using Optimize-DbContext, the generated types are not fully qualified and/or do not fully resolve the generated type, resulting in compile errors.

I have identified 3 scenarios:

1. The model type extends a class which has the same name of the class it extends (e.g. IdentityUser )
2. The model type uses the same name as a type found in the System namespace (e.g. Index)
3. The model type has the same name as the namespace in which it is located (e.g. Definition.Definition)

Include your code

I have committed a SLN with the generated compile errors here for your review: https://github.com/Mike-E-angelo/Stash/blob/master/EfCore6.Model/EfCore6.Model.sln

Include stack traces

NA

Include verbose output

PM> Optimize-DbContext -OutputDir Optimized -Verbose
Using project 'EfCore6.Model'.
Using startup project 'EfCore6.Model'.
Build started...
Build succeeded.
C:\Program Files\dotnet\dotnet.exe exec --depsfile ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\bin\Debug\net6.0\EfCore6.Model.deps.json --additionalprobingpath C:\Users\micha\.nuget\packages --additionalprobingpath "C:\Program Files\dotnet\sdk\NuGetFallbackFolder" --runtimeconfig ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\bin\Debug\net6.0\EfCore6.Model.runtimeconfig.json C:\Users\micha\.nuget\packages\microsoft.entityframeworkcore.tools\6.0.0-preview.7.21378.4\tools\netcoreapp2.0\any\ef.dll dbcontext optimize --output-dir Optimized --verbose --no-color --prefix-output --assembly ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\bin\Debug\net6.0\EfCore6.Model.dll --project ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\EfCore6.Model.csproj --startup-assembly ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\bin\Debug\net6.0\EfCore6.Model.dll --startup-project ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\EfCore6.Model.csproj --project-dir ...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\ --language C# --working-dir ...\Mike-E-angelo\Stash\EfCore6.Model --root-namespace EfCore6.Model --nullable
Using assembly 'EfCore6.Model'.
Using startup assembly 'EfCore6.Model'.
Using application base '...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\bin\Debug\net6.0'.
Using working directory '...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model'.
Using root namespace 'EfCore6.Model'.
Using project directory '...\Mike-E-angelo\Stash\EfCore6.Model\EfCore6.Model\'.
Remaining arguments: .
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Found IDesignTimeDbContextFactory implementation 'StorageBuilder'.
Found DbContext 'ApplicationState'.
Finding application service provider in assembly 'EfCore6.Model'...
Finding Microsoft.Extensions.Hosting service provider...
No static method 'CreateHostBuilder(string[])' was found on class 'Program'.
No application service provider was found.
Finding DbContext classes in the project...
Using DbContext factory 'StorageBuilder'.
Using context 'ApplicationState'.
Finding design-time services referenced by assembly 'EfCore6.Model'...
Finding design-time services referenced by assembly 'EfCore6.Model'...
No referenced design-time services were found.
Finding design-time services for provider 'Microsoft.EntityFrameworkCore.SqlServer'...
Using design-time services from provider 'Microsoft.EntityFrameworkCore.SqlServer'.
Finding IDesignTimeServices implementations in assembly 'EfCore6.Model'...
No design-time services were found.
The index {'UserId'} was not created on entity type 'IdentityUserRole<int>' as the properties are already covered by the index {'UserId', 'RoleId'}.
The index {'UserId'} was not created on entity type 'IdentityUserToken<int>' as the properties are already covered by the index {'UserId', 'LoginProvider', 'Name'}.
The property 'Index.UserId' was created in shadow state because there are no eligible CLR members with a matching name.
The property 'User.DefinitionId' was created in shadow state because there are no eligible CLR members with a matching name.
Successfully generated a compiled model, to use it call 'options.UseModel(ApplicationStateModel.Instance)'. Run this command again when the model is modified.
'ApplicationState' disposed.

Include provider and version information

EF Core version: 6.0.0-preview.7.21378.4 Database provider: Microsoft.EntityFrameworkCore.SqlServer Target framework: net6.0 Operating system: Windows 10 IDE: Visual Studio 2022 Preview 3.0

[AndriySvyryd]

This is something we can't fix automatically without drastically changing the infrastructure to use Roslyn. This is also that should be rather rare as all the listed cases are anti-patterns.

Workaround: Starting with 6.0.0-rc1 there is a way of achieving this by creating a class deriving from CSharpHelper and overriding ShouldUseFullName. Then registering the implementation as ICSharpHelper, see Design-time services.

[Mike-E-angelo]

Thank you very much for looking into this, @AndriySvyryd!

This is also that should be rather rare as all the listed cases are anti-patterns.

Source for this, please? It would seem if that were the case, warnings would be emitted by either Roslyn or R# during design/compile time, neither of which do so.

Either way, one developer's anti-pattern is another's strong use of the .NET type system. :P

Then register the implementation as ICSharpHelper, see Design-time services.

Cool, thank you for letting me know. 👍

[AndriySvyryd]

Source for this, please? It would seem if that were the case, warnings would be emitted by either Roslyn or R# during design/compile time, neither of which do so.

https://docs.microsoft.com/en-us/dotnet/standard/design-guidelines/names-of-namespaces

❌ DO NOT give the same name to types in namespaces within a single application model. ❌ DO NOT introduce generic type names such as Element, Node, Log, and Message. ❌ DO NOT use the same name for a namespace and a type in that namespace.

[AndriySvyryd]

BTW about https://devblogs.microsoft.com/dotnet/announcing-entity-framework-core-6-0-preview-5-compiled-models/#comment-10060

I couldn't answer because comments are now closed. You can use this to get your model "size":

var model = context.Model;

Console.WriteLine("Model has:");
Console.WriteLine($"  {model.GetEntityTypes().Count()} entity types");
Console.WriteLine($"  {model.GetEntityTypes().SelectMany(e => e.GetDeclaredProperties()).Count()} properties");
Console.WriteLine($"  {model.GetEntityTypes().SelectMany(e => e.GetDeclaredForeignKeys()).Count()} relationships");

But the benefit you get from a compiled model also depends on the shape of your model. In general if the startup time wasn't bothering you that much previously you probably won't notice a difference with a compiled model.

[Mike-E-angelo]

I appreciate you providing this information, @AndriySvyryd. I see now that you are talking guidelines and not analysis rules/warnings, which I would expect to be applied in the case of anti-patterns (although who knows).

DO NOT give the same name to types in namespaces within a single application model.

I suppose we'd have to really discern what is considered an application model here. In the case above, IdentityUser is inheriting another IdentityUser located in another referenced assembly. I can see the case here for not having two `IdentityUser' within the same assembly/project, but IMO that is not applicable here as an application-specific class is inheriting from a generalized framework class located in another assembly altogether.

DO NOT introduce generic type names such as Element, Node, Log, and Message.

So System.Index violates this guideline? 🙃

DO NOT use the same name for a namespace and a type in that namespace.

Yeah, TBH I am not a fan of this one. It actually bothers me a bit. 😬 It seems both redundant and lazy. It also makes me want to rename it just by looking at it. Nonetheless, it's still technically/syntactically correct so thought it would be a good use case to report.

I couldn't answer because comments are now closed. You can use this to get your model "size":

That is very cool! Thank you very much. I was interested in seeing how many relationships are found within the # of properties.

I am in a bit of a refactor ATM (trying to un-scope my DbContexts and replace with IDbContextFactory), but will try to get that together and see what the results are.

Thank you for taking the time to assist. 👍

[Mike-E-angelo]

Not to be a stickler here. 😁

There's also this one, which I think better applies to Index:

❌ DO NOT give types names that would conflict with any type in the Core namespaces.

I'm not a fan of this rule as there are SO many core namespaces/types and it's so very easy to meet a type name that already exists. Also, what happens when there's a new "Core" type that is introduced at some point later that conflicts with a type you've already created? This is the whole point of namespaces.

Along those lines, my feeling is that a lot of these guidelines are made to assist the tooling, which has been very deficient around these types of issues over the years. One of the many reasons I use ReSharper. :)

[AndriySvyryd]

Along those lines, my feeling is that a lot of these guidelines are made to assist the tooling

They are mostly for the benefit of the ones reading the code. I'd add a more general guideline - avoid type names that will need to be namespace-qualified. But as you said these are guidelines, not rules.

[Mike-E-angelo]

They are mostly for the benefit of the ones reading the code

Nodding along, @AndriySvyryd. I appreciate the discussion and hearing your viewpoint.

FWIW my stats are as follows:

Model has:
  126 entity types
  451 properties
  117 relationships
  568 total compilation targets

So at only 568 targets, it would seem I would not benefit much from a compiled model. This aligns with my observations when attempting to utilize a compiled model from my context. This would only yield ~114ms of startup time savings, if I understand correctly.

[AndriySvyryd]

This would only yield ~114ms of startup time savings, if I understand correctly.

This sounds about right.

[ghosttie]

Are there downsides to overriding CSharpHelper.ShouldUseFullName? Is there other generated code that's going to be wrong if we do that?

[AndriySvyryd]

Are there downsides to overriding CSharpHelper.ShouldUseFullName?

Not really, just potentially uglier code for compiled models and migration snapshots.

[ghosttie]

Is there a way we could make it smarter, so it only applies to Optimize-DbContext?

[AndriySvyryd]

Is there a way we could make it smarter, so it only applies to Optimize-DbContext?

No.

[HakanL]

@AndriySvyryd I'm facing an issue where I want to use this feature, but with an existing database that I can't modify, so even if there may be some anti-patterns, it is what it is but the Optimize-DbContext generates code that doesn't compile (due to not having full names in the references). I'm not sure I would create CSharpHelper.ShouldUseFullName when calling Optimize-DbContext? IMHO it would be nice with a parameter to Optimize-DbContext that specifies that full names should be used, is that feasible?

[Mike-E-angelo]

Workaround: Starting with 6.0.0-rc1 there is a way of achieving this by creating a class deriving from CSharpHelper

Hi @AndriySvyryd I am investigating this again and cannot seem to find this class. Can you point me in the direction of where it's located?

[ErikEJ]

In EFCore.Design

[Mike-E-angelo]

I see ICSharpHelper but not CSharperHelper. Do you have a full path and/or URL for reference @ErikEJ?

[Mike-E-angelo]

Ah, here we go: https://github.com/dotnet/efcore/blob/main/src/EFCore.Design/Design/Internal/CSharpHelper.cs

I was looking here: https://github.com/dotnet/efcore/tree/main/src/EFCore/Design/Internal

[HakanL]

I'm now on EF Core 6.0.6 and this part works great, but there's still one issue. I have a table named DayOfWeek (which in hindsight wasn't great, but I can't change it now). The problem is that the optimized CompiledModule causes a conflict between my own data model class for DayOfWeek and System.DayOfWeek in the auto-generated file. I have to manually add this line into the file to work around the issue. It would be good if this generated file from the Optimize-DbContext would always fully-qualify all types, at least as an option if not default. using DayOfWeek = Skumberg.DataModel.Models.DayOfWeek;

[AndriySvyryd]

This tracks adding a simple commandline switch - https://github.com/dotnet/efcore/issues/27203

[dharmeshtailor]

Ah, here we go: https://github.com/dotnet/efcore/blob/main/src/EFCore.Design/Design/Internal/CSharpHelper.cs

I was looking here: https://github.com/dotnet/efcore/tree/main/src/EFCore/Design/Internal

How do you reference this in the code? I am not able to find the CSharpHelper in "Microsoft.EntityFrameworkCore.Design.Internal". Am I missing something?

[AndriySvyryd]

How do you reference this in the code? I am not able to find the CSharpHelper in "Microsoft.EntityFrameworkCore.Design.Internal". Am I missing something?

Add a reference to Microsoft.EntityFrameworkCore.Design

[dharmeshtailor]

How do you reference this in the code? I am not able to find the CSharpHelper in "Microsoft.EntityFrameworkCore.Design.Internal". Am I missing something?

Add a reference to Microsoft.EntityFrameworkCore.Design

Here are the references:

Here's the error:

[AndriySvyryd]

@dharmeshtailor Did you try recompiling? If you are getting the EF1001 warning then the type is referenced correctly.

[dharmeshtailor]

@AndriySvyryd this is what I got on recompiling. It seems reference is correct.

I have .net 7.0 class library.

[dharmeshtailor]

@AndriySvyryd I have created a sample solution having same issue.

WebApplication4.zip

[AndriySvyryd]

Oh, it's because Microsoft.EntityFrameworkCore.Design is referenced as a build-only dependency. Edit the .csproj and replace

    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="7.0.5">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>

with

<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="7.0.5" />

[dharmeshtailor]

@AndriySvyryd Works perfectly. Thanks. :-)