Source Generator creates files but no dependency is added

[lucanatalidg]

Hi,

I’m having an issue that I’ll try to explain as clearly as possible.

I’ve created an IIncrementalGenerator project (Mapper) that looks for files starting with "MapConfig" in referencing projects.

For example, a file named MapConfigTestApi.cs contains the following mapping definitions:

[assembly: MapperConfiguration(typeof(SimpleClass), typeof(SimpleClassDto), "ToSimpleClassDto")]
[assembly: MapperConfiguration(typeof(SimpleAddress), typeof(SimpleAddressDto), "ToSimpleAddressDto")]

The TestApi project references the Mapper project like this:

<ProjectReference Include="..\mapper\mapper.csproj" OutputItemType="Analyzer" />

Here are the class definitions:

namespace ModelLibrary
{
    public class SimpleClass
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public SimpleAddress Address { get; set; }
    }

    public class SimpleClassDto
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public SimpleAddressDto Address { get; set; }
    }

    public class SimpleAddress
    {
        public int Id { get; set; }
        public string Street { get; set; }
    }

    public class SimpleAddressDto
    {
        public int Id { get; set; }
        public string Street { get; set; }
    }
}

Now, the issue I’m facing is this:

When the class definitions are inside the TestApi project, everything works fine.
The generated files appear under:
Dependencies → Analyzers → mapper → MapperGenerator.MapToGenerator → SimpleAddress_Map_SimpleAddressDto.g.cs
and
SimpleClass_Map_SimpleClassDto.g.cs.

However, if I move these classes into another project (e.g. ModelLibrary) that TestApi references, then no dependency is added to TestApi project.

But, if I add the following line to TestApi.csproj:

<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\generated</CompilerGeneratedFilesOutputPath>

I can see all the generated files there, and they are correct!

Additionally, if I remove the nested class (so that SimpleClass no longer contains the SimpleAddress property), everything works — even when the classes are declared in another project.

Just another thing, as workaround, if I add this line to TestApi.csproj

    <ItemGroup>
		<Compile Include="$(BaseIntermediateOutputPath)\generated\**\*_Map_*.g.cs" Visible="false" />
    </ItemGroup>

generated files are added to the project and everything works... but it is not the same thing :-/

Could you please help me understand why these files are not added as dependencies when the class definitions are located in a different project?

Many thanks! 🙏
Luca

[333fred]

However, if I move these classes into another project (e.g. ModelLibrary) that TestApi references, then no dependency is added to TestApi project.

This is what I would expect. Generators do not see files from dependencies; they only see symbols. You need to reference the generator from where the types you want to use in the generator are defined. I'm guessing that CompilerGeneratedFilesOutputPath bit was simply something left over from a previous run, and you would not see them in a fresh, clean run.