Source generators don't run when a file in AdditionalFiles is deleted

[Eli-Black-Work]

Version Used:
VS 17.2.0 Preview 2.0

Overview
If a source generator transforms an input file that's given to it via AdditionalFiles and then the input file is deleted, the generated source remains.

Steps to Reproduce:

Set up a project, like so:

MyProject.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">
	<PropertyGroup>
		<TargetFramework>net6.0</TargetFramework>
	</PropertyGroup>

	<ItemGroup>
		<ProjectReference Include="..\MyGenerator\MyGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" SetTargetFramework="TargetFramework=netstandard2.0" />
	</ItemGroup>

	<ItemGroup>
		<AdditionalFiles Include="$(ProjectDir)examplesubfolder\*.json" />
	</ItemGroup>
</Project>

Set up a generator, like so:

MyGenerator

[Generator]
public class ControllerGenerator : ISourceGenerator
{
    public void Execute(GeneratorExecutionContext context)
    {
        foreach (var file in context.AdditionalFiles)
        {
            string inputFilename = Path.GetFileNameWithoutExtension(file.Path);
            string outputFilename = inputFilename + ".g.cs";

            context.AddSource(outputFilename, $"class {inputFilename}");
        }
    }
}

1. Place two files in examplesubfolder\: one.json and two.json.
2. Compile MyProject.
3. VS shows two generated files: one.g.cs and two.g.cs
4. Delete two.json from examplesubfolder\
5. VS still shows two generated files: one.g.cs and two.g.cs, even though two.json has been deleted. The only way to fix this is to restart VS. Rebuilding MyProject or doing a clean and then build doesn't work.

Expected Behavior:
When two.json is deleted, its corresponding two.g.cs file should disappear from within VS.

Actual Behavior:
When two.json is deleted, the corresponding two.g.cs file remains visible in VS.

[jasonmalinowski]

@Bosch-Eli-Black trying this in 17.3 Preview 1.1 I do see the file disappear under the Solution Explorer and the generated content does disappear from intellisense as expected. I don't think we made any recent fixes here that would have fixed this. You're still seeing this as best you know?

[jasonmalinowski]

And oh I should also say @Bosch-Eli-Black the delay for updating the solution explorer list is intentionally very slow, so it might take a few seconds after everything else has settled down.

[Eli-Black-Work]

@jasonmalinowski Seems to be working for me on 17.3 Preview 1.1, too 🙂 The file disappears after 4-5 seconds.

Not sure what changed, if anything, but thanks for looking into this 🙂

[jasonmalinowski]

@Bosch-Eli-Black Thanks for the follow-up!

[Eli-Black-Work]

@jasonmalinowski No problem! 🙂