fixup! ObjectListFilter filter values to target type coercion (#589)

Author: xperiandri

src/FSharp.Data.GraphQL.Server.Middleware/FSharp.Data.GraphQL.Server.Middleware.fsproj

@@ -14,6 +14,12 @@
     <PublicSign Condition=" '$(OS)' != 'Windows_NT' ">true</PublicSign>-->
   </PropertyGroup>
 
+  <ItemGroup Label="InternalsVisibleTo">
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
+      <_Parameter1>FSharp.Data.GraphQL.Tests</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="FSharp.Control.Reactive" />
     <PackageReference Include="System.Reactive" />

src/FSharp.Data.GraphQL.Server.Middleware/ObjectListFilterModule.fs

@@ -195,25 +195,36 @@ module ObjectListFilter =
         |> Seq.head
 
     /// Maps an IComparer to a StringComparison value.
-    /// Returns ValueNone for null or Ordinal comparers (use default Expression.Equal path).
-    let private comparerToStringComparison (comparer : IComparer) =
+    /// Returns ValueNone for null or unsupported comparers.
+    let internal comparerToStringComparison (comparer : IComparer) =
         match comparer with
         | null -> ValueNone
         | :? StringComparer as sc ->
-            if obj.ReferenceEquals (sc, StringComparer.OrdinalIgnoreCase) then
-                ValueSome StringComparison.OrdinalIgnoreCase
-            elif obj.ReferenceEquals (sc, StringComparer.InvariantCultureIgnoreCase) then
-                ValueSome StringComparison.InvariantCultureIgnoreCase
-            elif obj.ReferenceEquals (sc, StringComparer.CurrentCultureIgnoreCase) then
-                ValueSome StringComparison.CurrentCultureIgnoreCase
-            elif obj.ReferenceEquals (sc, StringComparer.Ordinal) then
-                ValueSome StringComparison.Ordinal
-            elif obj.ReferenceEquals (sc, StringComparer.InvariantCulture) then
-                ValueSome StringComparison.InvariantCulture
-            elif obj.ReferenceEquals (sc, StringComparer.CurrentCulture) then
-                ValueSome StringComparison.CurrentCulture
+            let mutable isOrdinalIgnoreCase = false
+
+            if StringComparer.IsWellKnownOrdinalComparer (sc, &isOrdinalIgnoreCase) then
+                if isOrdinalIgnoreCase then
+                    ValueSome StringComparison.OrdinalIgnoreCase
+                else
+                    ValueSome StringComparison.Ordinal
             else
-                ValueNone
+                let mutable compareInfo = Unchecked.defaultof<Globalization.CompareInfo>
+                let mutable compareOptions = Globalization.CompareOptions.None
+
+                if StringComparer.IsWellKnownCultureAwareComparer (sc, &compareInfo, &compareOptions) then
+                    let isCurrentCulture = compareInfo.Equals Globalization.CultureInfo.CurrentCulture.CompareInfo
+                    let isInvariantCulture = compareInfo.Equals Globalization.CultureInfo.InvariantCulture.CompareInfo
+
+                    match compareOptions with
+                    | Globalization.CompareOptions.None when isCurrentCulture -> ValueSome StringComparison.CurrentCulture
+                    | Globalization.CompareOptions.IgnoreCase when isCurrentCulture ->
+                        ValueSome StringComparison.CurrentCultureIgnoreCase
+                    | Globalization.CompareOptions.None when isInvariantCulture -> ValueSome StringComparison.InvariantCulture
+                    | Globalization.CompareOptions.IgnoreCase when isInvariantCulture ->
+                        ValueSome StringComparison.InvariantCultureIgnoreCase
+                    | _ -> ValueNone
+                else
+                    ValueNone
         | _ -> ValueNone
 
      /// Gets the type from a MemberInfo (PropertyInfo or FieldInfo).

tests/FSharp.Data.GraphQL.Tests/FSharp.Data.GraphQL.Tests.fsproj

@@ -77,6 +77,7 @@
     <Compile Include="SelectLinqTests.fs" />
     <Compile Include="ObjectListFilter\ObjectListFilterLinqTests.fs" />
     <Compile Include="ObjectListFilter\ObjectListFilterLinqGenerateTests.fs" />
+    <Compile Include="ObjectListFilter\ObjectListFilterComparerMappingTests.fs" />
     <Compile Include="ObjectListFilter\TypeCoercionTests.Common.fs" />
     <Compile Include="ObjectListFilter\TypeCoercionValueTests.fs" />
     <Compile Include="ObjectListFilter\TypeCoercionFilterTests.fs" />

tests/FSharp.Data.GraphQL.Tests/ObjectListFilter/ObjectListFilterComparerMappingTests.fs

@@ -0,0 +1,34 @@
+[<Xunit.Trait (Tests.TraitType.Category, Tests.TraitName.Linq)>]
+[<Xunit.Trait (Tests.TraitType.Category, Tests.TraitName.ObjectListFilter)>]
+module FSharp.Data.GraphQL.Tests.ObjectListFilter.ComparerMapping.Tests
+
+open System
+open System.Collections
+open Xunit
+open FSharp.Data.GraphQL.Server.Middleware
+
+[<Fact>]
+let ``comparerToStringComparison maps well-known StringComparer instances`` () =
+    let testCases =
+        [
+            (StringComparer.OrdinalIgnoreCase :> IComparer, StringComparison.OrdinalIgnoreCase)
+            (StringComparer.InvariantCultureIgnoreCase :> IComparer, StringComparison.InvariantCultureIgnoreCase)
+            (StringComparer.CurrentCultureIgnoreCase :> IComparer, StringComparison.CurrentCultureIgnoreCase)
+            (StringComparer.Ordinal :> IComparer, StringComparison.Ordinal)
+            (StringComparer.InvariantCulture :> IComparer, StringComparison.InvariantCulture)
+            (StringComparer.CurrentCulture :> IComparer, StringComparison.CurrentCulture)
+        ]
+
+    for comparer, expected in testCases do
+        let actual = ObjectListFilter.comparerToStringComparison comparer |> wantValueSome
+        actual |> equals expected
+
+[<Fact>]
+let ``comparerToStringComparison returns ValueNone for unsupported comparers`` () =
+    let customComparer =
+        { new IComparer with
+            member _.Compare (_, _) = 0
+        }
+
+    ObjectListFilter.comparerToStringComparison null |> wantValueNone
+    ObjectListFilter.comparerToStringComparison customComparer |> wantValueNone