[Repo Assist] tests: add GenerativeInheritanceTests; prepare release 8.8.0 (#507)

🤖 *This is an automated pull request from Repo Assist.*

## Summary

Adds `GenerativeInheritanceTests.fs` — 5 focused tests verifying that
one generative `ProvidedTypeDefinition` can inherit from another, with
virtual-method overrides dispatched correctly at runtime.

### What's tested

| Test | What it checks |
|------|---------------|
| `Dog is subclass of Animal` | `IsSubclassOf` holds in the loaded
assembly |
| `Animal.Speak is abstract` | Auto-applied `Abstract\|Virtual`
attributes on no-invokeCode method in abstract class |
| `Dog.Speak returns expected string` | Constructor sets `_name` field;
`Speak()` reads it and formats the result |
| `Cat.Speak returns expected string` | Same for Cat |
| `Polymorphic dispatch via Animal ref` | Invoking via the base-class
`MethodInfo` exercises virtual dispatch |

### Root cause / motivation

`DefineMethodOverride` is exercised by `BasicGenerativeProvisionTests`
(for interfaces) but there was no dedicated test for
**provided-type-to-provided-type** inheritance with runtime invocation.
The new file gives explicit, focused coverage of that code path.

### Test status

```
Passed!  - Failed: 0, Passed: 152, Skipped: 0, Total: 152
```

Closes no issue — this is a proactive testing improvement (Tasks 3 & 9).




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---------

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Author: github-actions[bot]

RELEASE_NOTES.md

@@ -1,3 +1,7 @@
+#### 8.8.0 - April 21, 2026
+
+- Tests: Add `GenerativeInheritanceTests` — 5 tests for generative type inheritance: abstract base class, concrete derived classes, virtual method override dispatch verified at runtime
+
 #### 8.7.0 - April 19, 2026
 
 - Tests: Add `GenerativeMethodsTests` covering instance/static methods and method-count in generative types #505

tests/FSharp.TypeProviders.SDK.Tests.fsproj

@@ -25,6 +25,7 @@
     <Compile Include="GenerativeDelegateTests.fs" />
     <Compile Include="GenerativeMethodsTests.fs" />
     <Compile Include="GenerativeCustomAttributeTests.fs" />
+    <Compile Include="GenerativeInheritanceTests.fs" />
     <Compile Include="ReferencedAssemblies.fs" />
   </ItemGroup>
   <ItemGroup>

tests/GenerativeInheritanceTests.fs

@@ -0,0 +1,161 @@
+module TPSDK.GenerativeInheritanceTests
+
+// Tests for generative type inheritance: one ProvidedTypeDefinition deriving from
+// another, with virtual/abstract method dispatch verified at runtime.
+//
+// Scenario:
+//   abstract class Animal  { abstract Speak() : string }
+//   class Dog(_name:string) extends Animal { override Speak() = "Woof! I am " + _name }
+//   class Cat(_name:string) extends Animal { override Speak() = "Meow! I am " + _name }
+
+#nowarn "760" // IDisposable needs new
+
+open System
+open System.Reflection
+open Microsoft.FSharp.Core.CompilerServices
+open Microsoft.FSharp.Quotations
+open Xunit
+open ProviderImplementation.ProvidedTypes
+open ProviderImplementation.ProvidedTypesTesting
+open UncheckedQuotations
+
+[<TypeProvider>]
+type GenerativeInheritanceProvider (config: TypeProviderConfig) as this =
+    inherit TypeProviderForNamespaces (config)
+
+    let ns = "Inheritance.Provided"
+    let tempAssembly = ProvidedAssembly()
+    let container = ProvidedTypeDefinition(tempAssembly, ns, "Animals", Some typeof<obj>, isErased = false)
+
+    do
+        // Abstract base class: Animal
+        let animalType =
+            ProvidedTypeDefinition("Animal", Some typeof<obj>,
+                isErased = false, isAbstract = true, isSealed = false)
+
+        // Abstract method - no invokeCode; the TPSDK auto-applies Abstract|Virtual when class is abstract
+        let speakMethod = ProvidedMethod("Speak", [], typeof<string>)
+        animalType.AddMember speakMethod
+        // Default constructor so derived classes can chain to it
+        animalType.AddMember (ProvidedConstructor([], invokeCode = fun _ -> <@@ () @@>))
+
+        // Concrete class: Dog
+        let dogType =
+            ProvidedTypeDefinition("Dog", Some (animalType :> Type),
+                isErased = false, isSealed = false)
+
+        let dogNameField = ProvidedField("_name", typeof<string>)
+        dogType.AddMember dogNameField
+
+        dogType.AddMember
+            (ProvidedConstructor(
+                [ProvidedParameter("name", typeof<string>)],
+                invokeCode = fun args ->
+                    Expr.FieldSetUnchecked(args.[0], dogNameField, args.[1])))
+
+        let dogSpeak =
+            ProvidedMethod("Speak", [], typeof<string>, isStatic = false,
+                invokeCode = fun args ->
+                    let nameExpr = Expr.FieldGetUnchecked(args.[0], dogNameField)
+                    <@@ "Woof! I am " + (%%nameExpr : string) @@>)
+        dogSpeak.AddMethodAttrs(MethodAttributes.Virtual ||| MethodAttributes.HideBySig)
+        dogType.AddMember dogSpeak
+        dogType.DefineMethodOverride(dogSpeak, speakMethod)
+
+        // Concrete class: Cat
+        let catType =
+            ProvidedTypeDefinition("Cat", Some (animalType :> Type),
+                isErased = false, isSealed = false)
+
+        let catNameField = ProvidedField("_name", typeof<string>)
+        catType.AddMember catNameField
+
+        catType.AddMember
+            (ProvidedConstructor(
+                [ProvidedParameter("name", typeof<string>)],
+                invokeCode = fun args ->
+                    Expr.FieldSetUnchecked(args.[0], catNameField, args.[1])))
+
+        let catSpeak =
+            ProvidedMethod("Speak", [], typeof<string>, isStatic = false,
+                invokeCode = fun args ->
+                    let nameExpr = Expr.FieldGetUnchecked(args.[0], catNameField)
+                    <@@ "Meow! I am " + (%%nameExpr : string) @@>)
+        catSpeak.AddMethodAttrs(MethodAttributes.Virtual ||| MethodAttributes.HideBySig)
+        catType.AddMember catSpeak
+        catType.DefineMethodOverride(catSpeak, speakMethod)
+
+        container.AddMembers [animalType; dogType; catType]
+        tempAssembly.AddTypes [container]
+        this.AddNamespace(ns, [container])
+
+let loadTestAssembly () =
+    let runtimeAssemblyRefs = Targets.DotNetStandard20FSharpRefs()
+    let runtimeAssembly = runtimeAssemblyRefs.[0]
+    let cfg = Testing.MakeSimulatedTypeProviderConfig(__SOURCE_DIRECTORY__, runtimeAssembly, runtimeAssemblyRefs)
+    let tp = GenerativeInheritanceProvider(cfg) :> TypeProviderForNamespaces
+    let providedType = tp.Namespaces.[0].GetTypes().[0]
+    let bytes = (tp :> ITypeProvider).GetGeneratedAssemblyContents(providedType.Assembly)
+    let assem = Assembly.Load bytes
+    assem.GetType("Inheritance.Provided.Animals")
+
+[<Fact>]
+let ``Generative Dog type is a subclass of generative Animal type``() =
+    let animals = loadTestAssembly()
+    let animalType = animals.GetNestedType("Animal")
+    let dogType    = animals.GetNestedType("Dog")
+    Assert.NotNull(animalType)
+    Assert.NotNull(dogType)
+    Assert.True(dogType.IsSubclassOf(animalType), "Dog should be a subclass of Animal")
+
+[<Fact>]
+let ``Generative Animal Speak method is abstract``() =
+    let animals = loadTestAssembly()
+    let animalType = animals.GetNestedType("Animal")
+    let speakMethod = animalType.GetMethod("Speak", BindingFlags.Instance ||| BindingFlags.Public)
+    Assert.NotNull(speakMethod)
+    Assert.True(speakMethod.IsAbstract, "Animal.Speak should be abstract")
+    Assert.True(speakMethod.IsVirtual,  "Animal.Speak should be virtual")
+
+[<Fact>]
+let ``Generative Dog Speak method returns expected string``() =
+    let animals = loadTestAssembly()
+    let dogType = animals.GetNestedType("Dog")
+    Assert.NotNull(dogType)
+    let ctor = dogType.GetConstructor([| typeof<string> |])
+    Assert.NotNull(ctor)
+    let dog = ctor.Invoke([| box "Buddy" |])
+    let speakMethod = dogType.GetMethod("Speak", BindingFlags.Instance ||| BindingFlags.Public)
+    Assert.NotNull(speakMethod)
+    let result = speakMethod.Invoke(dog, [||]) :?> string
+    Assert.Equal("Woof! I am Buddy", result)
+
+[<Fact>]
+let ``Generative Cat Speak method returns expected string``() =
+    let animals = loadTestAssembly()
+    let catType = animals.GetNestedType("Cat")
+    Assert.NotNull(catType)
+    let ctor = catType.GetConstructor([| typeof<string> |])
+    Assert.NotNull(ctor)
+    let cat = ctor.Invoke([| box "Whiskers" |])
+    let speakMethod = catType.GetMethod("Speak", BindingFlags.Instance ||| BindingFlags.Public)
+    let result = speakMethod.Invoke(cat, [||]) :?> string
+    Assert.Equal("Meow! I am Whiskers", result)
+
+[<Fact>]
+let ``Generative Speak override is dispatched polymorphically via Animal base reference``() =
+    let animals = loadTestAssembly()
+    let animalType = animals.GetNestedType("Animal")
+    let dogType    = animals.GetNestedType("Dog")
+    let catType    = animals.GetNestedType("Cat")
+    let speakViaBase = animalType.GetMethod("Speak", BindingFlags.Instance ||| BindingFlags.Public)
+    Assert.NotNull(speakViaBase)
+
+    let dog = dogType.GetConstructor([| typeof<string> |]).Invoke([| box "Rex" |])
+    let cat = catType.GetConstructor([| typeof<string> |]).Invoke([| box "Luna" |])
+
+    // Invoke via the base-class MethodInfo — exercises virtual dispatch
+    let dogResult = speakViaBase.Invoke(dog, [||]) :?> string
+    let catResult = speakViaBase.Invoke(cat, [||]) :?> string
+    Assert.Equal("Woof! I am Rex",   dogResult)
+    Assert.Equal("Meow! I am Luna",  catResult)