Only apply AsSplitQuery in VerifyEntity when a collection is included

src/EfLocalDb.MSTest/LocalDbTestBase_Verify.cs

@@ -68,12 +68,12 @@ QueryableSettingsTask<TEntity> InnerVerifyEntity<TEntity>(object id, string sour
         var expression = Expression.Lambda<Func<TEntity, bool>>(predicate, parameter);
 
         return new(
-            set.AsSplitQuery(),
+            set,
             null,
             async (settings, source) =>
             {
                 using var verifier = BuildVerifier(settings, sourceFile);
-                return await verifier.Verify(source.SingleOrDefaultAsync(expression));
+                return await verifier.Verify(QuerySplitting.SplitIfIncludesCollection(source).SingleOrDefaultAsync(expression));
             });
     }
 }

src/EfLocalDb.MSTest/QueryableSettingsTask/QuerySplitting.cs

@@ -0,0 +1,68 @@
+using System.Collections;
+
+namespace EfLocalDb;
+
+// AsSplitQuery only changes how collections are loaded. So only apply it when an Include loads a collection,
+// since a query that loads no collection is a single query either way (and Verify.EntityFramework throws for it).
+static class QuerySplitting
+{
+    public static IQueryable<TEntity> SplitIfIncludesCollection<TEntity>(IQueryable<TEntity> source)
+        where TEntity : class
+    {
+        if (IncludesCollection(source.Expression))
+        {
+            return source.AsSplitQuery();
+        }
+
+        return source;
+    }
+
+    static bool IncludesCollection(Expression expression)
+    {
+        while (expression is MethodCallExpression
+               {
+                   Method.IsStatic: true,
+                   Arguments.Count: > 0
+               } call)
+        {
+            if (IsInclude(call.Method) &&
+                call.Arguments.Count > 1)
+            {
+                var argument = Unquote(call.Arguments[1]);
+                // a string Include can not be checked without resolving the path, so it is assumed to be a collection
+                if (argument is not LambdaExpression lambda ||
+                    IsCollection(lambda.Body.Type))
+                {
+                    return true;
+                }
+            }
+
+            expression = call.Arguments[0];
+        }
+
+        return false;
+    }
+
+    static Expression Unquote(Expression expression)
+    {
+        while (expression is UnaryExpression
+               {
+                   NodeType: ExpressionType.Quote
+               } unary)
+        {
+            expression = unary.Operand;
+        }
+
+        return expression;
+    }
+
+    static bool IsInclude(MethodInfo method) =>
+        method.DeclaringType == typeof(EntityFrameworkQueryableExtensions) &&
+        method.Name is
+            nameof(EntityFrameworkQueryableExtensions.Include) or
+            nameof(EntityFrameworkQueryableExtensions.ThenInclude);
+
+    static bool IsCollection(Type type) =>
+        type != typeof(string) &&
+        typeof(IEnumerable).IsAssignableFrom(type);
+}

src/EfLocalDb.NUnit/EfLocalDb.NUnit.csproj

@@ -17,6 +17,7 @@
     <Compile Include="..\EfLocalDb.MSTest\SharedDbWithTransactionAttribute.cs" Link="SharedDbWithTransactionAttribute.cs" />
     <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\QueryableSettingsTask.cs" Link="QueryableSettingsTask\QueryableSettingsTask.cs" />
     <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\NestedQueryableSettingsTask.cs" Link="QueryableSettingsTask\NestedQueryableSettingsTask.cs" />
+    <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\QuerySplitting.cs" Link="QueryableSettingsTask\QuerySplitting.cs" />
     <PackageReference Include="Verify.EntityFramework" />
     <PackageReference Include="Verify.NUnit" />
     <PackageReference Include="Argon" />

src/EfLocalDb.NUnit/LocalDbTestBase_Verify.cs

@@ -68,12 +68,12 @@ QueryableSettingsTask<TEntity> InnerVerifyEntity<TEntity>(object id, string sour
         var expression = Expression.Lambda<Func<TEntity, bool>>(predicate, parameter);
 
         return new(
-            set.AsSplitQuery(),
+            set,
             null,
             async (settings, source) =>
             {
                 using var verifier = BuildVerifier(sourceFile, settings);
-                return await verifier.Verify(source.SingleOrDefaultAsync(expression));
+                return await verifier.Verify(QuerySplitting.SplitIfIncludesCollection(source).SingleOrDefaultAsync(expression));
             });
     }
 }

src/EfLocalDb.TUnit/EfLocalDb.TUnit.csproj

@@ -17,6 +17,7 @@
     <Compile Include="..\EfLocalDb.MSTest\SharedDbWithTransactionAttribute.cs" Link="SharedDbWithTransactionAttribute.cs" />
     <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\QueryableSettingsTask.cs" Link="QueryableSettingsTask\QueryableSettingsTask.cs" />
     <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\NestedQueryableSettingsTask.cs" Link="QueryableSettingsTask\NestedQueryableSettingsTask.cs" />
+    <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\QuerySplitting.cs" Link="QueryableSettingsTask\QuerySplitting.cs" />
     <PackageReference Include="Verify.EntityFramework" />
     <PackageReference Include="TUnit" />
     <PackageReference Include="Verify.TUnit" />

src/EfLocalDb.TUnit/LocalDbTestBase_Verify.cs

@@ -68,12 +68,12 @@ QueryableSettingsTask<TEntity> InnerVerifyEntity<TEntity>(object id, string sour
         var expression = Expression.Lambda<Func<TEntity, bool>>(predicate, parameter);
 
         return new(
-            set.AsSplitQuery(),
+            set,
             null,
             async (settings, source) =>
             {
                 using var verifier = BuildVerifier(sourceFile, settings);
-                return await verifier.Verify(source.SingleOrDefaultAsync(expression));
+                return await verifier.Verify(QuerySplitting.SplitIfIncludesCollection(source).SingleOrDefaultAsync(expression));
             });
     }
 }

src/EfLocalDb.Xunit.V3/EfLocalDb.Xunit.V3.csproj

@@ -17,6 +17,7 @@
     <Compile Include="..\EfLocalDb.MSTest\SharedDbWithTransactionAttribute.cs" Link="SharedDbWithTransactionAttribute.cs" />
     <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\QueryableSettingsTask.cs" Link="QueryableSettingsTask\QueryableSettingsTask.cs" />
     <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\NestedQueryableSettingsTask.cs" Link="QueryableSettingsTask\NestedQueryableSettingsTask.cs" />
+    <Compile Include="..\EfLocalDb.MSTest\QueryableSettingsTask\QuerySplitting.cs" Link="QueryableSettingsTask\QuerySplitting.cs" />
     <PackageReference Include="Verify.EntityFramework" />
     <PackageReference Include="Verify.XunitV3" />
     <PackageReference Include="Argon" />

src/EfLocalDb.Xunit.V3/LocalDbTestBase_Verify.cs

@@ -68,12 +68,12 @@ QueryableSettingsTask<TEntity> InnerVerifyEntity<TEntity>(object id, string sour
         var expression = Expression.Lambda<Func<TEntity, bool>>(predicate, parameter);
 
         return new(
-            set.AsSplitQuery(),
+            set,
             null,
             async (settings, source) =>
             {
                 using var verifier = BuildVerifier(settings, sourceFile);
-                return await verifier.Verify(source.SingleOrDefaultAsync(expression));
+                return await verifier.Verify(QuerySplitting.SplitIfIncludesCollection(source).SingleOrDefaultAsync(expression));
             });
     }
 }