Support for projectable generic methods

tests/EntityFrameworkCore.Projectables.FunctionalTests/ExtensionsMethods/ExtensionMethodTests.cs

@@ -63,4 +63,4 @@ namespace EntityFrameworkCore.Projectables.FunctionalTests.ExtensionMethods
             return Verifier.Verify(query.ToQueryString());
         }
     }
-}
+}

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/Entity.cs

@@ -0,0 +1,8 @@
+namespace EntityFrameworkCore.Projectables.FunctionalTests.Generics
+{
+    public record Entity : IEntity
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+    }
+}

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/EntityExtensions.cs

@@ -0,0 +1,11 @@
+using System.Linq;
+
+namespace EntityFrameworkCore.Projectables.FunctionalTests.Generics
+{
+    public static class EntityExtensions
+    {
+        [Projectable]
+        public static TEntity? DefaultIfIdIsNegative<TEntity>(this TEntity entity) where TEntity : IEntity
+            => entity.Id >= 0 ? entity : default;
+    }
+}

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/GenericExtensionMethodTests.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.FunctionalTests.Helpers;
+using Microsoft.EntityFrameworkCore;
+using VerifyXunit;
+using Xunit;
+
+namespace EntityFrameworkCore.Projectables.FunctionalTests.Generics
+{
+    [UsesVerify]
+    public class GenericFunctionTests
+    {
+        [Fact]
+        public Task DefaultIfIdIsNegative()
+        {
+            using var context = new SampleDbContext<Entity>();
+            var query = context.Set<Entity>()
+                .Select(x => x.DefaultIfIdIsNegative());
+
+            return Verifier.Verify(query.ToQueryString());
+        }
+    }
+}

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/GenericFunctionTests.DefaultIfIdIsNegative.verified.txt

@@ -0,0 +1,5 @@
+SELECT CASE
+    WHEN [e].[Id] >= 0 THEN CAST(1 AS bit)
+    ELSE CAST(0 AS bit)
+END, [e].[Id], [e].[Name]
+FROM [Entity] AS [e]

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/GenericFunctionTests.QueryOrderedByDefault.verified.txt

@@ -0,0 +1,3 @@
+SELECT [e].[Id]
+FROM [Entity] AS [e]
+ORDER BY [e].[Id]

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/IEntity.cs

@@ -0,0 +1,7 @@
+namespace EntityFrameworkCore.Projectables.FunctionalTests.Generics
+{
+    public interface IEntity
+    {
+        int Id { get; }
+    }
+}

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/MultipleGenericsTests.TestMultipleArguments.verified.txt

@@ -0,0 +1,2 @@
+SELECT CAST(1 AS bit), [e].[Id], [e].[Name]
+FROM [Entity] AS [e]

tests/EntityFrameworkCore.Projectables.FunctionalTests/Generics/MultipleGenericsTests.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.FunctionalTests.Helpers;
+using Microsoft.EntityFrameworkCore;
+using VerifyXunit;
+using Xunit;
+
+namespace EntityFrameworkCore.Projectables.FunctionalTests.Generics
+{
+    [UsesVerify]
+    public class MultipleGenericsTests
+    {
+        [Projectable]
+        public static object? Coalesce<T1, T2>(T1? t1, T2 t2)
+            => t1 != null ? t1 : t2;
+
+        [Fact]
+        public Task TestMultipleArguments()
+        {
+            using var context = new SampleDbContext<Entity>();
+            
+            var query = context.Set<Entity>()
+                .Select(x => Coalesce(x.Id, x.Name));
+
+            return Verifier.Verify(query.ToQueryString());
+        }
+
+
+        [Fact]
+        public void MultipleInvocations()
+        {
+            using var context = new SampleDbContext<Entity>(Infrastructure.CompatibilityMode.Full);
+
+            var query1 = context.Set<Entity>()
+                .Select(x => Coalesce(x.Id, x.Name))
+                .ToQueryString();
+
+            var query2 = context.Set<Entity>()
+                .Select(x => Coalesce(x.Name, x.Id))
+                .ToQueryString();
+
+            Assert.NotEqual(query1, query2);
+        }
+    }
+}