Migrations do not fully qualify types, resulting in compile errors

[tpodolak]

File a bug

dotnet ef migrations add MigrationName generates code without fully qualified class names when referencing properties

modelBuilder.Entity("TestProject1.Models.Products.Product", b =>
                {
                    b.Property<string>("Id")
                        .HasColumnType("text");

                    b.Property<Label>("Label") <--  CS0104
                        .HasColumnType("jsonb");

                    b.HasKey("Id");

                    b.ToTable("Product");
                });

resulting in CS0104 compiler error in snapshot,migration and Migration.Designer.cs. That is happening the moment we have same class name in different namespaces (with same root namespace) see sample code below. This is very inconvenient as the only workaround I found is to rename classes - which result in prefixed names eg Label -> VariantLabel
This looks similar to #25523, however newest preview version of EF Core/EF Core Tools still generates conflicting code in migrations.

As far as I can tell, bug is located here

efcore/src/EFCore.Design/Migrations/Design/CSharpSnapshotGenerator.cs

Line 476 in 85b0670

var propertyBuilderName = $"{entityTypeBuilderName}.Property<{Code.Reference(clrType)}>({Code.Literal(property.Name)})";

as Code.Reference(clrType) is called without fullName flag

Include your code

Sample project attached TestProject1.zip

Include stack traces

N/A

Include verbose output

dotnet ef migrations add Init --verbose
Using project '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj'.
Using startup project '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj'.
Writing '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/obj/TestProject1.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=/tmp/tmpeI2Ypu.tmp /verbosity:quiet /nologo /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj
Writing '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/obj/TestProject1.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=/tmp/tmp6s7fdL.tmp /verbosity:quiet /nologo /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj
Build started...
dotnet build /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj /verbosity:quiet /nologo

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:01.90
Build succeeded.
dotnet exec --depsfile /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/bin/Debug/net5.0/TestProject1.deps.json --additionalprobingpath /home/tpodolak/.nuget/packages --additionalprobingpath /usr/share/dotnet/sdk/NuGetFallbackFolder --runtimeconfig /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/bin/Debug/net5.0/TestProject1.runtimeconfig.json /home/tpodolak/.dotnet/tools/.store/dotnet-ef/6.0.0-preview.7.21378.4/dotnet-ef/6.0.0-preview.7.21378.4/tools/netcoreapp3.1/any/tools/netcoreapp2.0/any/ef.dll migrations add Init --assembly /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/bin/Debug/net5.0/TestProject1.dll --project /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj --startup-assembly /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/bin/Debug/net5.0/TestProject1.dll --startup-project /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/TestProject1.csproj --project-dir /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/ --root-namespace TestProject1 --language C# --working-dir /media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1 --verbose
Using assembly 'TestProject1'.
Using startup assembly 'TestProject1'.
Using application base '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/bin/Debug/net5.0'.
Using working directory '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1'.
Using root namespace 'TestProject1'.
Using project directory '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/'.
Remaining arguments: .
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Finding application service provider in assembly 'TestProject1'...
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...
Found DbContext 'MyDataContext'.
Using context 'MyDataContext'.
Finding design-time services for provider 'Npgsql.EntityFrameworkCore.PostgreSQL'...
Using design-time services from provider 'Npgsql.EntityFrameworkCore.PostgreSQL'.
Finding design-time services referenced by assembly 'TestProject1'...
Finding design-time services referenced by assembly 'TestProject1'...
No referenced design-time services were found.
Finding IDesignTimeServices implementations in assembly 'TestProject1'...
No design-time services were found.
DetectChanges starting for 'MyDataContext'.
DetectChanges completed for 'MyDataContext'.
Writing migration to '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/Migrations/20210908134406_Init.cs'.
Writing model snapshot to '/media/tpodolak/b43e2cf3-1a1e-436b-96d5-25448f19a97c/home/tpodolak/Code/TestProject1/TestProject1/Migrations/MyDataContextModelSnapshot.cs'.
'MyDataContext' disposed.
Done. To undo this action, use 'ef migrations remove'

Include provider and version information

EF Core version: 5.0.9
EF Tools: both 5.x and 6.x generates invalid code
Database provider: Npgsql.EntityFrameworkCore.PostgreSQL
Target framework: .NET 5.0
Operating system:
IDE: Rider

[AndriySvyryd]

Detecting cases like this is out of scope for EF. However in 6.0 you will be able to specify which types should be fully qualified by overriding CSharpHelper.ShouldUseFullName using IDesignTimeServices