Remove the ISourceGenerator type constraint

This change simplifies the pattern for testing IIncrementalGenerator
without removing the ability to test ISourceGenerator.

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs

@@ -281,21 +281,21 @@ namespace Microsoft.CodeAnalysis.Testing
                 return ImmutableArray<Diagnostic>.Empty;
             }
 
-            return await VerifySourceGeneratorAsync(Language, GetSourceGenerators().ToImmutableArray(), testState, ApplySourceGeneratorAsync, verifier.PushContext("Source generator application"), cancellationToken);
+            return await VerifySourceGeneratorAsync(Language, sourceGenerators, testState, ApplySourceGeneratorsAsync, verifier.PushContext("Source generator application"), cancellationToken);
         }
 
         private protected async Task<ImmutableArray<Diagnostic>> VerifySourceGeneratorAsync(
             string language,
             ImmutableArray<Type> sourceGenerators,
             SolutionState testState,
-            Func<ImmutableArray<Type>, Project, IVerifier, CancellationToken, Task<(Project project, ImmutableArray<Diagnostic> diagnostics)>> getFixedProject,
+            Func<ImmutableArray<Type>, Project, IVerifier, CancellationToken, Task<(Project project, ImmutableArray<Diagnostic> diagnostics)>> applySourceGenerators,
             IVerifier verifier,
             CancellationToken cancellationToken)
         {
             var project = await CreateProjectAsync(new EvaluatedProjectState(testState, ReferenceAssemblies), testState.AdditionalProjects.Values.Select(additionalProject => new EvaluatedProjectState(additionalProject, ReferenceAssemblies)).ToImmutableArray(), cancellationToken);
 
             ImmutableArray<Diagnostic> diagnostics;
-            (project, diagnostics) = await getFixedProject(sourceGenerators, project, verifier, cancellationToken).ConfigureAwait(false);
+            (project, diagnostics) = await applySourceGenerators(sourceGenerators, project, verifier, cancellationToken).ConfigureAwait(false);
 
             // After applying the source generator, compare the resulting string to the inputted one
             if (!TestBehaviors.HasFlag(TestBehaviors.SkipGeneratedSourcesCheck))
@@ -1153,11 +1153,11 @@ namespace Microsoft.CodeAnalysis.Testing
 
         protected virtual async Task<(Compilation compilation, ImmutableArray<Diagnostic> generatorDiagnostics)> GetProjectCompilationAsync(Project project, IVerifier verifier, CancellationToken cancellationToken)
         {
-            var (finalProject, generatorDiagnostics) = await ApplySourceGeneratorAsync(GetSourceGenerators().ToImmutableArray(), project, verifier, cancellationToken).ConfigureAwait(false);
+            var (finalProject, generatorDiagnostics) = await ApplySourceGeneratorsAsync(GetSourceGenerators().ToImmutableArray(), project, verifier, cancellationToken).ConfigureAwait(false);
             return ((await finalProject.GetCompilationAsync(cancellationToken).ConfigureAwait(false))!, generatorDiagnostics);
         }
 
-        private protected async Task<(Project project, ImmutableArray<Diagnostic> diagnostics)> ApplySourceGeneratorAsync(ImmutableArray<Type> sourceGeneratorTypes, Project project, IVerifier verifier, CancellationToken cancellationToken)
+        private protected async Task<(Project project, ImmutableArray<Diagnostic> diagnostics)> ApplySourceGeneratorsAsync(ImmutableArray<Type> sourceGeneratorTypes, Project project, IVerifier verifier, CancellationToken cancellationToken)
         {
             var compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
             verifier.True(compilation is { });
@@ -1228,6 +1228,7 @@ namespace Microsoft.CodeAnalysis.Testing
                 else
                 {
                     var iincrementalGeneratorType = isourceGeneratorType.GetTypeInfo().Assembly.GetType("Microsoft.CodeAnalysis.IIncrementalGenerator");
+                    verifier.True(iincrementalGeneratorType?.IsAssignableFrom(sourceGenerators[i].GetType()) ?? false, $"'{sourceGenerators[i].GetType().FullName}' must implement '{iincrementalGeneratorType.FullName}' or '{isourceGeneratorType.FullName}'");
                     var asGeneratorMethod = (from method in isourceGeneratorType.GetTypeInfo().Assembly.GetType("Microsoft.CodeAnalysis.GeneratorExtensions")!.GetMethods()
                                              where method is { Name: "AsSourceGenerator", IsStatic: true, IsPublic: true }
                                              let parameterTypes = method.GetParameters().Select(parameter => parameter.ParameterType).ToArray()

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.MSTest/SourceGeneratorVerifier.cs

@@ -7,7 +7,7 @@ namespace Microsoft.CodeAnalysis.CSharp.Testing.MSTest
     public static class SourceGeneratorVerifier
     {
         public static SourceGeneratorVerifier<TSourceGenerator> Create<TSourceGenerator>()
-            where TSourceGenerator : ISourceGenerator, new()
+            where TSourceGenerator : new()
         {
             return new SourceGeneratorVerifier<TSourceGenerator>();
         }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.MSTest/SourceGeneratorVerifier`1.cs

@@ -7,7 +7,7 @@ using Microsoft.CodeAnalysis.Testing.Verifiers;
 namespace Microsoft.CodeAnalysis.CSharp.Testing.MSTest
 {
     public class SourceGeneratorVerifier<TSourceGenerator> : CSharpSourceGeneratorVerifier<TSourceGenerator, MSTestVerifier>
-        where TSourceGenerator : ISourceGenerator, new()
+        where TSourceGenerator : new()
     {
     }
 }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.NUnit/SourceGeneratorVerifier.cs

@@ -7,7 +7,7 @@ namespace Microsoft.CodeAnalysis.CSharp.Testing.NUnit
     public static class SourceGeneratorVerifier
     {
         public static SourceGeneratorVerifier<TSourceGenerator> Create<TSourceGenerator>()
-            where TSourceGenerator : ISourceGenerator, new()
+            where TSourceGenerator : new()
         {
             return new SourceGeneratorVerifier<TSourceGenerator>();
         }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.NUnit/SourceGeneratorVerifier`1.cs

@@ -7,7 +7,7 @@ using Microsoft.CodeAnalysis.Testing.Verifiers;
 namespace Microsoft.CodeAnalysis.CSharp.Testing.NUnit
 {
     public class SourceGeneratorVerifier<TSourceGenerator> : CSharpSourceGeneratorVerifier<TSourceGenerator, NUnitVerifier>
-        where TSourceGenerator : ISourceGenerator, new()
+        where TSourceGenerator : new()
     {
     }
 }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.XUnit/SourceGeneratorVerifier.cs

@@ -7,7 +7,7 @@ namespace Microsoft.CodeAnalysis.CSharp.Testing.XUnit
     public static class SourceGeneratorVerifier
     {
         public static SourceGeneratorVerifier<TSourceGenerator> Create<TSourceGenerator>()
-            where TSourceGenerator : ISourceGenerator, new()
+            where TSourceGenerator : new()
         {
             return new SourceGeneratorVerifier<TSourceGenerator>();
         }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.XUnit/SourceGeneratorVerifier`1.cs

@@ -7,7 +7,7 @@ using Microsoft.CodeAnalysis.Testing.Verifiers;
 namespace Microsoft.CodeAnalysis.CSharp.Testing.XUnit
 {
     public class SourceGeneratorVerifier<TSourceGenerator> : CSharpSourceGeneratorVerifier<TSourceGenerator, XUnitVerifier>
-        where TSourceGenerator : ISourceGenerator, new()
+        where TSourceGenerator : new()
     {
     }
 }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing/CSharpSourceGeneratorTest`2.cs

@@ -9,7 +9,7 @@ using Microsoft.CodeAnalysis.Testing;
 namespace Microsoft.CodeAnalysis.CSharp.Testing
 {
     public class CSharpSourceGeneratorTest<TSourceGenerator, TVerifier> : SourceGeneratorTest<TVerifier>
-        where TSourceGenerator : ISourceGenerator, new()
+        where TSourceGenerator : new()
         where TVerifier : IVerifier, new()
     {
         private static readonly LanguageVersion DefaultLanguageVersion =

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing/CSharpSourceGeneratorVerifier`2.cs

@@ -7,7 +7,7 @@ using Microsoft.CodeAnalysis.Testing;
 namespace Microsoft.CodeAnalysis.CSharp.Testing
 {
     public class CSharpSourceGeneratorVerifier<TSourceGenerator, TVerifier> : SourceGeneratorVerifier<TSourceGenerator, CSharpSourceGeneratorTest<TSourceGenerator, TVerifier>, TVerifier>
-        where TSourceGenerator : ISourceGenerator, new()
+        where TSourceGenerator : new()
         where TVerifier : IVerifier, new()
     {
     }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.SourceGenerators.Testing/SourceGeneratorTest`1.cs

@@ -18,7 +18,7 @@ namespace Microsoft.CodeAnalysis.Testing
         /// <summary>
         /// Returns the source generators being tested - to be implemented in non-abstract class.
         /// </summary>
-        /// <returns>The <see cref="ISourceGenerator"/> to be used.</returns>
+        /// <returns>The <see cref="ISourceGenerator"/> and/or <see cref="T:Microsoft.CodeAnalysis.IIncrementalGenerator"/> to be used.</returns>
         protected override abstract IEnumerable<Type> GetSourceGenerators();
     }
 }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.SourceGenerators.Testing/SourceGeneratorVerifier`3.cs

@@ -7,11 +7,11 @@ namespace Microsoft.CodeAnalysis.Testing
     /// <summary>
     /// A default verifier for source generators.
     /// </summary>
-    /// <typeparam name="TSourceGenerator">The <see cref="ISourceGenerator"/> to test.</typeparam>
+    /// <typeparam name="TSourceGenerator">The <see cref="ISourceGenerator"/> or <see cref="T:Microsoft.CodeAnalysis.IIncrementalGenerator"/> to test.</typeparam>
     /// <typeparam name="TTest">The test implementation to use.</typeparam>
     /// <typeparam name="TVerifier">The type of verifier to use.</typeparam>
     public class SourceGeneratorVerifier<TSourceGenerator, TTest, TVerifier>
-           where TSourceGenerator : ISourceGenerator, new()
+           where TSourceGenerator : new()
            where TTest : SourceGeneratorTest<TVerifier>, new()
            where TVerifier : IVerifier, new()
     {

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing.MSTest/SourceGeneratorVerifier.vb

@@ -1,7 +1,7 @@
 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 Module SourceGeneratorVerifier
-    Public Function Create(Of TSourceGenerator As {ISourceGenerator, New})() As SourceGeneratorVerifier(Of TSourceGenerator)
+    Public Function Create(Of TSourceGenerator As New)() As SourceGeneratorVerifier(Of TSourceGenerator)
         Return New SourceGeneratorVerifier(Of TSourceGenerator)
     End Function
 End Module

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing.MSTest/SourceGeneratorVerifier`1.vb

@@ -2,6 +2,6 @@
 
 Imports Microsoft.CodeAnalysis.Testing.Verifiers
 
-Public Class SourceGeneratorVerifier(Of TSourceGenerator As {ISourceGenerator, New})
+Public Class SourceGeneratorVerifier(Of TSourceGenerator As New)
     Inherits VisualBasicSourceGeneratorVerifier(Of TSourceGenerator, MSTestVerifier)
 End Class

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing.NUnit/SourceGeneratorVerifier.vb

@@ -1,7 +1,7 @@
 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 Module SourceGeneratorVerifier
-    Public Function Create(Of TSourceGenerator As {ISourceGenerator, New})() As SourceGeneratorVerifier(Of TSourceGenerator)
+    Public Function Create(Of TSourceGenerator As New)() As SourceGeneratorVerifier(Of TSourceGenerator)
         Return New SourceGeneratorVerifier(Of TSourceGenerator)
     End Function
 End Module

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing.NUnit/SourceGeneratorVerifier`1.vb

@@ -2,6 +2,6 @@
 
 Imports Microsoft.CodeAnalysis.Testing.Verifiers
 
-Public Class SourceGeneratorVerifier(Of TSourceGenerator As {ISourceGenerator, New})
+Public Class SourceGeneratorVerifier(Of TSourceGenerator As New)
     Inherits VisualBasicSourceGeneratorVerifier(Of TSourceGenerator, NUnitVerifier)
 End Class

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing.XUnit/SourceGeneratorVerifier.vb

@@ -1,7 +1,7 @@
 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 Module SourceGeneratorVerifier
-    Public Function Create(Of TSourceGenerator As {ISourceGenerator, New})() As SourceGeneratorVerifier(Of TSourceGenerator)
+    Public Function Create(Of TSourceGenerator As New)() As SourceGeneratorVerifier(Of TSourceGenerator)
         Return New SourceGeneratorVerifier(Of TSourceGenerator)
     End Function
 End Module

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing.XUnit/SourceGeneratorVerifier`1.vb

@@ -2,6 +2,6 @@
 
 Imports Microsoft.CodeAnalysis.Testing.Verifiers
 
-Public Class SourceGeneratorVerifier(Of TSourceGenerator As {ISourceGenerator, New})
+Public Class SourceGeneratorVerifier(Of TSourceGenerator As New)
     Inherits VisualBasicSourceGeneratorVerifier(Of TSourceGenerator, XUnitVerifier)
 End Class

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing/VisualBasicSourceGeneratorTest`2.vb

@@ -2,7 +2,7 @@
 
 Imports Microsoft.CodeAnalysis.Testing
 
-Public Class VisualBasicSourceGeneratorTest(Of TSourceGenerator As {ISourceGenerator, New}, TVerifier As {IVerifier, New})
+Public Class VisualBasicSourceGeneratorTest(Of TSourceGenerator As New, TVerifier As {IVerifier, New})
     Inherits SourceGeneratorTest(Of TVerifier)
 
     Private Shared ReadOnly DefaultLanguageVersion As LanguageVersion =

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.VisualBasic.SourceGenerators.Testing/VisualBasicSourceGeneratorVerifier`2.vb

@@ -2,6 +2,6 @@
 
 Imports Microsoft.CodeAnalysis.Testing
 
-Public Class VisualBasicSourceGeneratorVerifier(Of TSourceGenerator As {ISourceGenerator, New}, TVerifier As {IVerifier, New})
+Public Class VisualBasicSourceGeneratorVerifier(Of TSourceGenerator As New, TVerifier As {IVerifier, New})
     Inherits SourceGeneratorVerifier(Of TSourceGenerator, VisualBasicSourceGeneratorTest(Of TSourceGenerator, TVerifier), TVerifier)
 End Class