add test

Author: majocha

tests/FSharp.Compiler.ComponentTests/FSharp.Compiler.ComponentTests.fsproj

@@ -277,6 +277,7 @@
     <Compile Include="Interop\Literals.fs" />
     <Compile Include="Scripting\Interactive.fs" />
     <Compile Include="Scripting\TypeCheckOnlyTests.fs" />
+    <Compile Include="TypeChecks\TypeRelations.fs" />
     <Compile Include="TypeChecks\SeqTypeCheckTests.fs" />
     <Compile Include="TypeChecks\CheckDeclarationsTests.fs" />
     <Compile Include="TypeChecks\Graph\Utils.fs" />

tests/FSharp.Compiler.ComponentTests/TypeChecks/CrgpLibrary.fs

@@ -0,0 +1,34 @@
+module MyModule
+
+type IFoo<'T when 'T :> IFoo<'T>> =
+    abstract member Bar: other:'T -> unit
+
+[<AbstractClass>]
+type FooBase() =
+    
+    interface IFoo<FooBase> with
+        member this.Bar (other: FooBase) = ()
+
+[<Sealed>]
+type FooDerived<'T>() =
+    inherit FooBase()
+    
+    interface IFoo<FooDerived<'T>> with
+        member this.Bar other = ()
+
+type IFooContainer<'T> =
+    abstract member Foo: FooDerived<'T>
+
+let inline bar<'a when 'a :> IFoo<'a>> (x: 'a) (y: 'a) = x.Bar y
+let inline takeSame<'a> (x: 'a) (y: 'a) = ()
+
+// Successfully compiles under .NET 9 + F# 9
+// Error under .NET 10 + F# 10: Program.fs(26,13): Error FS0193 : The type 'FooDerived<'TId>' does not match the type 'FooBase'
+let callBar_NewlyBroken (foo1: IFooContainer<'TId>) (foo2: IFooContainer<'TId>) =
+    bar foo1.Foo foo2.Foo
+    
+// Successfully compiles under both versions
+let callBar (foo1: IFooContainer<'TId>) (foo2: IFooContainer<'TId>) =
+    let id1 = foo1.Foo
+    let id2 = foo2.Foo
+    bar id1 id2

tests/FSharp.Compiler.ComponentTests/TypeChecks/TypeRelations.fs

@@ -0,0 +1,12 @@
+module TypeChecks.TypeRelations
+
+open Xunit
+open FSharp.Test.Compiler
+open FSharp.Test
+
+[<Theory; FileInlineData("CrgpLibrary.fs")>]
+let ``Unsolved type variables are not cached`` compilation =
+    compilation
+    |> getCompilation
+    |> typecheck
+    |> shouldSucceed