Enabling auto-compiled models on EF 9.0.0-rc.2 causes syntax errors on publish with certain element type mappings

[zotanmew]

I'm testing the new EF Core 9 feature auto-compiled models right now, and have noticed that enabling it causes build failures due to syntax errors in generated code (files suffixed EntityType.g.cs).

Example errors observed:

.../net9.0/EmojiEntityType.g.cs(142,32): error CS1026: ) expected
.../net9.0/AntennaEntityType.g.cs(713,25): error CS1026: ) expected
.../net9.0/EmojiEntityType.g.cs(143,135): error CS1002: ; expected
.../net9.0/AntennaEntityType.g.cs(714,123): error CS1002: ; expected
.../net9.0/AntennaEntityType.g.cs(714,123): error CS1513: } expected
.../net9.0/EmojiEntityType.g.cs(143,135): error CS1513: } expected
.../net9.0/FilterEntityType.g.cs(197,117): error CS1026: ) expected
.../net9.0/FilterEntityType.g.cs(208,27): error CS1002: ; expected
.../net9.0/FilterEntityType.g.cs(208,27): error CS1513: } expected
.../net9.0/OauthAppEntityType.g.cs(327,24): error CS1026: ) expected
.../net9.0/MessagingMessageEntityType.g.cs(331,23): error CS1026: ) expected
.../net9.0/MessagingMessageEntityType.g.cs(332,123): error CS1002: ; expected
.../net9.0/OauthAppEntityType.g.cs(328,137): error CS1002: ; expected
.../net9.0/MessagingMessageEntityType.g.cs(332,123): error CS1513: } expected
.../net9.0/OauthAppEntityType.g.cs(328,137): error CS1513: } expected
.../net9.0/OauthAppEntityType.g.cs(391,23): error CS1026: ) expected
.../net9.0/GalleryPostEntityType.g.cs(236,27): error CS1026: ) expected
.../net9.0/OauthAppEntityType.g.cs(392,125): error CS1002: ; expected
.../net9.0/OauthAppEntityType.g.cs(392,125): error CS1513: } expected
.../net9.0/GalleryPostEntityType.g.cs(237,131): error CS1002: ; expected
.../net9.0/GalleryPostEntityType.g.cs(237,131): error CS1513: } expected
.../net9.0/MetaEntityType.g.cs(141,32): error CS1026: ) expected
.../net9.0/MetaEntityType.g.cs(142,145): error CS1002: ; expected
.../net9.0/GalleryPostEntityType.g.cs(394,24): error CS1026: ) expected
.../net9.0/MetaEntityType.g.cs(142,145): error CS1513: } expected
.../net9.0/GalleryPostEntityType.g.cs(395,121): error CS1002: ; expected
.../net9.0/GalleryPostEntityType.g.cs(395,121): error CS1513: } expected

Affected project/branch: https://iceshrimp.dev/iceshrimp/Iceshrimp.NET/src/branch/wip/net90-optimize2 (error occurs when building the Iceshrimp.Backend subfolder).

I'm not sure whether this is a bug in EF, or a bug with Npgsql. I've tested it against EF versions 9.0.0-rc.2, 9.0.0 (GA), as well as various rtm nightly builds. The issue also occurs against efcore.pg version 9.0.0-rc.2-ci.20241106T153535.

Any input would be greatly appreciated!

[roji]

Could you provide a bit more help with narrowing down the problem? For example, a minimal console program which contains only the offending parts from Iceshrimp.NET (which is quite a big project) would be very helpful, otherwise you're asking us to figure out Iceshrimp.NET and narrow the problem down ourselves (that would probably mean it'll take longer to work on this).

[roji]

Another thing which would be very helpful, is if you could simply attempt to do the same with the SQL Server provider. There's a pretty strong likelihood that you'd see the same trouble there, at which point this issue would need to move to the EF repo.

[zotanmew]

I tried to reproduce this in a minimal console project when rc.2 came out, but I sadly wasn't successful, and assumed it was an issue in EF that would be fixed before release, which ended up not being the case.

I'm not experienced with SQL Server, but I'll have a look when I have time, thanks for the hint!

Regarding building the project, you should be able to reproduce it by simply running make publish on the branch mentioned, since it's a build failure due to syntax errors. I don't think any other dependencies should be required, though I perfectly understand that not having a minimally reproducible example makes this difficult to debug. I did have a look at the source generator component when I first ran into this, but it was quite difficult to understand, especially because of the nature of the error & the complexity of the models. One thing I did discover is that copying an entity as closely as possible into a new project did not reproduce the error.

[zotanmew]

Update: I think I removed all Npgsql references in the project & swapped it out with SqlServer, which has caused the same errors. I'll go open an issue on dotnet/ef, and will keep trying to isolate it.

Nevermind, the build system is messing with me, I'll keep trying.

[zotanmew]

Okay, I've managed to verify that the issue does not occur with SQL Server. I got the application starting up without OnModelCreating being called & with no syntax errors on build.

[zotanmew]

Now I'm properly confused, I also managed to get it to work with Npgsql. The syntax errors seem to only occur when using the MSBuild task, not when using dotnet ef dbcontext optimize. Curiously, this matches the SQL server behavior, though that one produced one invalid cast instead of a barrage of syntax errors.

[zotanmew]

I have a feeling (though can't verify this) that the issue lies with Microsoft.EntityFrameworkCore.Tasks. I'll try to integrate the dotnet-ef call into our build pipeline for now.

[roji]

@zotanmew it would be very odd if there's a difference between dotnet ef and Microsoft.EntityFrameworkCore.Tasks, both end up calling into the same code path... I'd advise concentrating on getting a minimal repro together...

[zotanmew]

I'll get right to it, thanks so much for the advice! It is indeed very strange that they behave differently. I've been having strange issues with the .NET 9 tooling all day, I'd be wondering if I'm having memory corruption issues if everything else wasn't working properly...

[zotanmew]

It seems like all affected entity types have a List<string> mapped to a character varying(n)[]. Setting them to [NotMapped] makes the errors go away.

[zotanmew]

I managed to trace builds not being properly reproducible/consistent to <EFScaffoldModelStage>build</EFScaffoldModelStage>, removing that makes every publish on the same codebase throw the same errors.

The MSBuild Task <> global tool behavior difference appears to be consistently reproducible, which is concerning.

[zotanmew]

List<int> types (with no explicit postgres type mapping) do not appear to have the same issue.

[zotanmew]

New error! Setting all List<string> objects to [NotMapped] yields error : Cannot scaffold C# literals of type 'System.Reflection.NullabilityInfoContext'. The provider should implement CoreTypeMapping.GenerateCodeLiteral to support using it at design time.

Curiously, this now also applies to dotnet ef dbcontext optimize, which worked before this change.

[zotanmew]

Yep, that's it. Minimally reproducible example:

dotnet new webapi -o api
cd api

DbContext.cs

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using Microsoft.EntityFrameworkCore;

namespace api;

public class DatabaseContext(DbContextOptions<DatabaseContext> options) : DbContext(options)
{
	public virtual DbSet<Example> Objects { get; init; } = null!;

	protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
		optionsBuilder.UseNpgsql();
	}

	protected override void OnModelCreating(ModelBuilder modelBuilder) {
		modelBuilder.Entity<Example>().HasKey(p => p.Id);
	}
}

public class Example
{
	[Key]
	[Column("id", TypeName = "character varying(32)")]
	[StringLength(32)]
	public string Id { get; set; } = null!;

	[Column("test", TypeName = "character varying(32)[]")]
	public List<string> Test { get; set; } = [];
}

api.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

    <PropertyGroup>
        <TargetFramework>net9.0</TargetFramework>
        <Nullable>enable</Nullable>
        <ImplicitUsings>enable</ImplicitUsings>
        <EFOptimizeContext>true</EFOptimizeContext>
        <EFPrecompileQueriesStage>none</EFPrecompileQueriesStage>
    </PropertyGroup>

    <ItemGroup>
        <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.0-rc.2" />
        <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.0" />
        <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="9.0.0" />
        <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.0" />
        <PackageReference Include="Microsoft.EntityFrameworkCore.Tasks" Version="9.0.0" />
        <PackageReference Include="Microsoft.AspNetCore.DataProtection.EntityFrameworkCore" Version="9.0.0" />
    </ItemGroup>

</Project>

Program.cs

// [...]
builder.Services.AddNpgsql<DatabaseContext>(null);
// [...]

> dotnet publish
.../obj/Release/net9.0/ExampleEntityType.g.cs(140,31): error CS1026: ) expected
.../obj/Release/net9.0/ExampleEntityType.g.cs(141,129): error CS1002: ; expected
.../obj/Release/net9.0/ExampleEntityType.g.cs(141,129): error CS1513: } expected

[zotanmew]

Swapping it out for SqlServer (which is quick and easy here), no errors are reported.