FSharp issue with EFCoreExpressionAttribute or UseFSharpTypes (#246)

* add test for linq2db/linq2db#3743

* update test

* proposed fix

Author: MaceWindu

Directory.Packages.props

@@ -20,5 +20,8 @@
 		<PackageVersion Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="6.0.4" />
 		<PackageVersion Include="Microsoft.EntityFrameworkCore.Sqlite" Version="6.0.5" />
 		<PackageVersion Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.5" />
+
+		<PackageVersion Include="EntityFrameworkCore.FSharp" Version="6.0.7" />
+		<PackageVersion Include="FSharp.Core" Version="6.0.5" />
 	</ItemGroup>
 </Project>

Source/LinqToDB.EntityFrameworkCore/EFCoreMetadataReader.cs

@@ -523,7 +523,7 @@ public override int GetHashCode()
 					var objExpr = new SqlTransparentExpression(Expression.Constant(DefaultValue.GetValue(type), type), _mappingSource?.FindMapping(propInfo));
 
 					var newExpression = _dependencies.MemberTranslatorProvider.Translate(objExpr, propInfo, propInfo.GetMemberType(), _logger!);
-					if (newExpression != null)
+					if (newExpression != null && newExpression != objExpr)
 					{
 						var parametersArray = new Expression[] { objExpr };
 						result = ConvertToExpressionAttribute(propInfo, newExpression, parametersArray);

Tests/LinqToDB.EntityFrameworkCore.FSharpTests/LinqToDB.EntityFrameworkCore.FSharpTests.fsproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <Import Project="..\..\Build\linq2db.Tests.props" />
+
+    <PropertyGroup>
+        <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <Compile Include="Tests.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\..\Source\LinqToDB.EntityFrameworkCore\linq2db.EntityFrameworkCore.csproj" />
+        <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" />
+        <PackageReference Include="EntityFrameworkCore.FSharp" />
+        <PackageReference Include="FSharp.Core" />
+    </ItemGroup>
+
+</Project>

Tests/LinqToDB.EntityFrameworkCore.FSharpTests/Tests.fs

@@ -0,0 +1,61 @@
+module LinqToDB.EntityFrameworkCore.FSharpTests
+
+open System.Linq
+open LinqToDB
+open System.ComponentModel.DataAnnotations
+open System.ComponentModel.DataAnnotations.Schema
+open Microsoft.EntityFrameworkCore
+open EntityFrameworkCore.FSharp.Extensions
+open NUnit.Framework
+
+[<CLIMutable>]
+type WithIdentity = {
+    [<Key>]
+    [<DatabaseGenerated(DatabaseGeneratedOption.Identity)>]
+    Id : int
+    Name : string
+}
+
+type AppDbContext(options: DbContextOptions<AppDbContext>) =
+    inherit DbContext(options)
+
+    [<DefaultValue>] val mutable WithIdentity : DbSet<WithIdentity>
+    member this.CompaniesInformation
+        with get() = this.WithIdentity
+        and set v = this.WithIdentity <- v
+
+type TestDbContextFactory() =
+    member this.CreateDbContext() =
+        let options = new DbContextOptionsBuilder<AppDbContext>()
+        options.UseSqlite("DataSource=:memory:").UseFSharpTypes() |> ignore
+        new AppDbContext(options.Options)
+
+[<TestFixture>]
+type Tests() =
+
+    [<Test>]
+    member this.TestLeftJoin() =
+        let context = TestDbContextFactory().CreateDbContext()
+        let q =
+            context
+                .WithIdentity
+                .Join(
+                    context.WithIdentity,
+                    (fun p -> p.Id),
+                    (fun c -> c.Id),
+                    (fun p c ->
+                    {|
+                        Person = p
+                        Company = c
+                    |}) )
+                .LeftJoin(
+                    context.WithIdentity,
+                    (fun partialPerson cInfo -> partialPerson.Company.Id = cInfo.Id),
+                    (fun partialPerson cInfo ->
+                    {|
+                        Company = partialPerson.Company
+                        CompanyInformation = cInfo
+                        Person = partialPerson.Person
+                    |}) )
+        //q.ToArray() |> ignore
+        q.ToLinqToDB().ToString() |> ignore

linq2db.EFCore.sln

@@ -41,6 +41,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LinqToDB.EntityFrameworkCor
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LinqToDB.EntityFrameworkCore.SQLite.Tests", "Tests\LinqToDB.EntityFrameworkCore.SQLite.Tests\LinqToDB.EntityFrameworkCore.SQLite.Tests.csproj", "{615C5697-5FA7-490C-8812-3D61994A8AC1}"
 EndProject
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LinqToDB.EntityFrameworkCore.FSharpTests", "Tests\LinqToDB.EntityFrameworkCore.FSharpTests\LinqToDB.EntityFrameworkCore.FSharpTests.fsproj", "{ECF4637B-1C93-4D87-BDF2-E7F4DF7ED5C9}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -71,6 +73,10 @@ Global
 		{615C5697-5FA7-490C-8812-3D61994A8AC1}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{615C5697-5FA7-490C-8812-3D61994A8AC1}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{615C5697-5FA7-490C-8812-3D61994A8AC1}.Release|Any CPU.Build.0 = Release|Any CPU
+		{ECF4637B-1C93-4D87-BDF2-E7F4DF7ED5C9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{ECF4637B-1C93-4D87-BDF2-E7F4DF7ED5C9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{ECF4637B-1C93-4D87-BDF2-E7F4DF7ED5C9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{ECF4637B-1C93-4D87-BDF2-E7F4DF7ED5C9}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE