Fix tests

src/Compilers/CSharp/Test/Emit/Attributes/AttributeTests_NativeInteger.cs

@@ -1249,6 +1249,7 @@ static void Main()
         }
 
         [Fact]
+        [WorkItem(45519, "https://github.com/dotnet/roslyn/issues/45519")]
         public void EmitAttribute_PartialMethods()
         {
             var source =
@@ -1260,13 +1261,13 @@ public void EmitAttribute_PartialMethods()
     static partial void F2(nuint x);
 }";
             var comp = CreateCompilation(source, options: TestOptions.ReleaseDll.WithMetadataImportOptions(MetadataImportOptions.All), parseOptions: TestOptions.Regular9);
-            // Ideally should not emit any attributes. Compare with dynamic/object.
-            var expected =
-@"Program
-    void F2(System.UIntPtr x)
-        [NativeInteger] System.UIntPtr x
-";
-            AssertNativeIntegerAttributes(comp, expected);
+            comp.VerifyEmitDiagnostics(
+                // (4,25): error CS8824: Partial method declarations 'void Program.F2(nuint x)' and 'void Program.F2(UIntPtr x)' must have identical parameter types and identical return types.
+                //     static partial void F2(System.UIntPtr x) { }
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "F2").WithArguments("void Program.F2(nuint x)", "void Program.F2(UIntPtr x)").WithLocation(4, 25),
+                // (5,25): error CS8824: Partial method declarations 'void Program.F1(IntPtr x)' and 'void Program.F1(nint x)' must have identical parameter types and identical return types.
+                //     static partial void F1(nint x) { }
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "F1").WithArguments("void Program.F1(IntPtr x)", "void Program.F1(nint x)").WithLocation(5, 25));
         }
 
         // Shouldn't depend on [NullablePublicOnly].

src/Compilers/CSharp/Test/Symbol/Symbols/ExtendedPartialMethodsTests.cs

@@ -2687,7 +2687,13 @@ partial class C
     public partial IEnumerable<string> M2() => null!;
 }";
             var comp = CreateCompilation(source, parseOptions: TestOptions.RegularWithExtendedPartialMethods);
-            comp.VerifyDiagnostics();
+            comp.VerifyDiagnostics(
+                // (8,27): error CS8824: Partial method declarations 'string? C.M1()' and 'string C.M1()' must have identical parameter types and identical return types.
+                //     public partial string M1() => "hello";
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "M1").WithArguments("string? C.M1()", "string C.M1()").WithLocation(8, 27),
+                // (11,40): error CS8824: Partial method declarations 'IEnumerable<string?> C.M2()' and 'IEnumerable<string> C.M2()' must have identical parameter types and identical return types.
+                //     public partial IEnumerable<string> M2() => null!;
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "M2").WithArguments("IEnumerable<string?> C.M2()", "IEnumerable<string> C.M2()").WithLocation(11, 40));
         }
 
         [Fact, WorkItem(44930, "https://github.com/dotnet/roslyn/issues/44930")]
@@ -2967,7 +2973,13 @@ partial class C
     public partial object M2() => null;
 }";
             var comp = CreateCompilation(source, parseOptions: TestOptions.RegularWithExtendedPartialMethods);
-            comp.VerifyDiagnostics();
+            comp.VerifyDiagnostics(
+                // (5,28): error CS8824: Partial method declarations 'object C.M1()' and 'dynamic C.M1()' must have identical parameter types and identical return types.
+                //     public partial dynamic M1() => null;
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "M1").WithArguments("object C.M1()", "dynamic C.M1()").WithLocation(5, 28),
+                // (8,27): error CS8824: Partial method declarations 'dynamic C.M2()' and 'object C.M2()' must have identical parameter types and identical return types.
+                //     public partial object M2() => null;
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "M2").WithArguments("dynamic C.M2()", "object C.M2()").WithLocation(8, 27));
         }
 
         [Fact, WorkItem(44930, "https://github.com/dotnet/roslyn/issues/44930")]
@@ -2985,7 +2997,13 @@ partial class C
     public partial IntPtr M2() => default;
 }";
             var comp = CreateCompilation(source, parseOptions: TestOptions.RegularWithExtendedPartialMethods);
-            comp.VerifyDiagnostics();
+            comp.VerifyDiagnostics(
+                // (7,25): error CS8824: Partial method declarations 'IntPtr C.M1()' and 'nint C.M1()' must have identical parameter types and identical return types.
+                //     public partial nint M1() => 0;
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "M1").WithArguments("IntPtr C.M1()", "nint C.M1()").WithLocation(7, 25),
+                // (10,27): error CS8824: Partial method declarations 'nint C.M2()' and 'IntPtr C.M2()' must have identical parameter types and identical return types.
+                //     public partial IntPtr M2() => default;
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "M2").WithArguments("nint C.M2()", "IntPtr C.M2()").WithLocation(10, 27));
         }
 
         [Fact, WorkItem(44930, "https://github.com/dotnet/roslyn/issues/44930")]