Fixed program declaration in explicit namespace

Author: benhopkinstech

src/Framework/AspNetCoreAnalyzers/src/SourceGenerators/PublicTopLevelProgramGenerator.cs

@@ -10,6 +10,7 @@ namespace Microsoft.AspNetCore.SourceGenerators;
 [Generator]
 public class PublicProgramSourceGenerator : IIncrementalGenerator
 {
+    private const string Program = "Program";
     private const string PublicPartialProgramClassSource = """
 // <auto-generated />
 #pragma warning disable CS1591
@@ -20,22 +21,31 @@ public partial class Program { }
     public void Initialize(IncrementalGeneratorInitializationContext context)
     {
         var internalGeneratedProgramClass = context.CompilationProvider.Select(static (compilation, cancellationToken) =>
+        {
+            // If there is a user-declared Program in a non-global namespace, skip generation
+            if (compilation.GetSymbolsWithName(Program, SymbolFilter.Type, cancellationToken)
+                .OfType<INamedTypeSymbol>()
+                .Any(symbol => !symbol.ContainingNamespace.IsGlobalNamespace))
+            {
+                return false;
+            }
+
             // Get the entry point associated with the compilation, this maps to the Main method definition
             // Get the containing symbol of the entry point, this maps to the Program class
-            compilation.GetEntryPoint(cancellationToken)?.ContainingSymbol is INamedTypeSymbol
+            return compilation.GetEntryPoint(cancellationToken)?.ContainingSymbol is INamedTypeSymbol
             {
+                // If the program class is already public, we don't need to generate anything
+                DeclaredAccessibility: not Accessibility.Public,
                 // If the discovered `Program` type is not a class then its not
                 // generated and has been defined in source, so we can skip it
-                // If the program class is already public, we don't need to generate anything.
-                DeclaredAccessibility: not Accessibility.Public,
                 TypeKind: TypeKind.Class,
                 // If there are multiple partial declarations, then do nothing since we don't want
                 // to trample on visibility explicitly set by the user
                 DeclaringSyntaxReferences: { Length: 1 } declaringSyntaxReferences
             } &&
-            // If the `Program` class is already declared in user code, we don't need to generate anything.
-            declaringSyntaxReferences.Single().GetSyntax(cancellationToken) is not ClassDeclarationSyntax
-        );
+            // If the `Program` class is already declared in user code, we don't need to generate anything
+            declaringSyntaxReferences.Single().GetSyntax(cancellationToken) is not ClassDeclarationSyntax;
+        });
 
         context.RegisterSourceOutput(internalGeneratedProgramClass, (context, result) =>
         {

src/Framework/AspNetCoreAnalyzers/test/SourceGenerators/PublicTopLevelProgramGeneratorTests.cs

@@ -30,10 +30,17 @@ public partial class Program { }
         await VerifyCS.VerifyAsync(source, "PublicTopLevelProgram.Generated.g.cs", expected);
     }
 
-    [Fact]
-    public async Task DoesNotGeneratesSource_IfProgramIsAlreadyPublic()
+    [Theory]
+    [InlineData("public partial class Program { }")]
+    [InlineData("""
+namespace Foo
+{
+    public partial class Program { }
+}
+""")]
+    public async Task DoesNotGeneratesSource_IfProgramIsAlreadyPublic(string declaration)
     {
-        var source = """
+        var source = $$"""
 using Microsoft.AspNetCore.Builder;
 
 var app = WebApplication.Create();
@@ -42,16 +49,23 @@ public async Task DoesNotGeneratesSource_IfProgramIsAlreadyPublic()
 
 app.Run();
 
-public partial class Program { }
+{{declaration}}
 """;
 
         await VerifyCS.VerifyAsync(source);
     }
 
-    [Fact]
-    public async Task DoesNotGeneratesSource_IfProgramDeclaresExplicitInternalAccess()
+    [Theory]
+    [InlineData("internal partial class Program { }")]
+    [InlineData("""
+namespace Foo
+{
+    internal partial class Program { }
+}
+""")]
+    public async Task DoesNotGeneratesSource_IfProgramDeclaresExplicitInternalAccess(string declaration)
     {
-        var source = """
+        var source = $$"""
 using Microsoft.AspNetCore.Builder;
 
 var app = WebApplication.Create();
@@ -60,7 +74,7 @@ public async Task DoesNotGeneratesSource_IfProgramDeclaresExplicitInternalAccess
 
 app.Run();
 
-internal partial class Program { }
+{{declaration}}
 """;
 
         await VerifyCS.VerifyAsync(source);
@@ -88,6 +102,31 @@ public static void Main()
         await VerifyCS.VerifyAsync(source);
     }
 
+    [Fact]
+    public async Task DoesNotGeneratorSource_ExplicitPublicProgramClassInNamespace()
+    {
+        var source = """
+using Microsoft.AspNetCore.Builder;
+
+namespace Foo
+{
+    public class Program
+    {
+        public static void Main()
+        {
+            var app = WebApplication.Create();
+
+            app.MapGet("/", () => "Hello, World!");
+
+            app.Run();
+        }
+    }
+}
+""";
+
+        await VerifyCS.VerifyAsync(source);
+    }
+
     [Fact]
     public async Task DoesNotGeneratorSource_ExplicitInternalProgramClass()
     {
@@ -110,6 +149,31 @@ public static void Main()
         await VerifyCS.VerifyAsync(source);
     }
 
+    [Fact]
+    public async Task DoesNotGeneratorSource_ExplicitInternalProgramClassInNamespace()
+    {
+        var source = """
+using Microsoft.AspNetCore.Builder;
+
+namespace Foo
+{
+    internal class Program
+    {
+        public static void Main()
+        {
+            var app = WebApplication.Create();
+
+            app.MapGet("/", () => "Hello, World!");
+
+            app.Run();
+        }
+    }
+}
+""";
+
+        await VerifyCS.VerifyAsync(source);
+    }
+
     [Theory]
     [InlineData("interface")]
     [InlineData("struct")]
@@ -129,6 +193,33 @@ public static void Main(string[] args)
         app.Run();
     }
 }
+""";
+
+        await VerifyCS.VerifyAsync(source);
+    }
+
+    [Theory]
+    [InlineData("interface")]
+    [InlineData("struct")]
+    public async Task DoesNotGeneratorSource_ExplicitInternalProgramTypeInNamespace(string type)
+    {
+        var source = $$"""
+using Microsoft.AspNetCore.Builder;
+
+namespace Foo
+{
+    internal {{type}} Program
+    {
+        public static void Main(string[] args)
+        {
+            var app = WebApplication.Create();
+
+            app.MapGet("/", () => "Hello, World!");
+
+            app.Run();
+        }
+    }
+}
 """;
 
         await VerifyCS.VerifyAsync(source);