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Merged
roji merged 1 commit into from
Jul 28, 2025
Merged

Specify some lambda parameters/return type explicitly #36454

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3 changes: 3 additions & 0 deletions .editorconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -281,3 +281,6 @@ dotnet_naming_rule.everything_else_naming.severity = suggestion

# ReSharper properties
resharper_local_function_body = expression_body

# CS9236: Compiling requires binding the lambda expression at least 100 times
dotnet_diagnostic.CS9236.severity = error
59 changes: 32 additions & 27 deletions test/EFCore.Specification.Tests/Query/ComplexNavigationsQueryTestBase.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2941,20 +2941,23 @@ public virtual async Task Member_pushdown_chain_3_levels_deep(bool async)
{
using var ctx = CreateContext();

var query = from l1 in ctx.LevelOne
orderby l1.Id
where (from l2 in ctx.LevelTwo
orderby l2.Id
where l2.Level1_Optional_Id == l1.Id
select (from l3 in ctx.LevelThree
orderby l3.Id
where l3.Level2_Required_Id == l2.Id
select (from l4 in ctx.LevelFour
where l4.Level3_Required_Id == l3.Id
orderby l4.Id
select l4).FirstOrDefault()).FirstOrDefault()).FirstOrDefault().Name
!= "Foo"
select l1;
#pragma warning disable CS9236 // Compiling requires binding the lambda expression at least 200 times
var query = ctx.LevelOne
.OrderBy(l1 => l1.Id)
.Where(l1 => ctx.LevelTwo
.OrderBy(l2 => l2.Id)
.Where(l2 => l2.Level1_Optional_Id == l1.Id)
.Select(l2 => ctx.LevelThree
.OrderBy(l3 => l3.Id)
.Where(l3 => l3.Level2_Required_Id == l2.Id)
.Select(l3 => ctx.LevelFour
.Where(bool (Level4 l4) => l4.Level3_Required_Id == l3.Id)
.OrderBy(int (Level4 l4) => l4.Id)
.FirstOrDefault())
.FirstOrDefault())
.FirstOrDefault()
.Name != "Foo");
#pragma warning restore CS9236

_ = async ? await query.ToListAsync() : query.ToList();
}
Expand All @@ -2965,18 +2968,20 @@ public virtual async Task Member_pushdown_chain_3_levels_deep_entity(bool async)
{
using var ctx = CreateContext();

var query = from l1 in ctx.LevelOne
orderby l1.Id
select (from l2 in ctx.LevelTwo
orderby l2.Id
where l2.Level1_Optional_Id == l1.Id
select (from l3 in ctx.LevelThree
orderby l3.Id
where l3.Level2_Required_Id == l2.Id
select (from l4 in ctx.LevelFour
where l4.Level3_Required_Id == l3.Id
orderby l4.Id
select l4).FirstOrDefault()).FirstOrDefault()).FirstOrDefault();
var query = ctx.LevelOne
.OrderBy(l1 => l1.Id)
.Select(l1 => ctx.LevelTwo
.OrderBy(l2 => l2.Id)
.Where(l2 => l2.Level1_Optional_Id == l1.Id)
.Select(l2 => ctx.LevelThree
.OrderBy(l3 => l3.Id)
.Where(l3 => l3.Level2_Required_Id == l2.Id)
.Select(l3 => ctx.LevelFour
.Where(bool (Level4 l4) => l4.Level3_Required_Id == l3.Id)
.OrderBy(int (Level4 l4) => l4.Id)
.FirstOrDefault())
.FirstOrDefault())
.FirstOrDefault());

_ = async ? await query.ToListAsync() : query.ToList();
}
Expand Down Expand Up @@ -4052,7 +4057,7 @@ public virtual Task Max_in_multi_level_nested_subquery(bool async)
LevelFour = new
{
xx.OneToOne_Required_FK2.OneToOne_Required_FK3.Id,
Result = (xx.OneToOne_Required_FK2.OneToMany_Optional3.Max(xxx => (int?)xxx.Id) ?? 0)
Result = (xx.OneToOne_Required_FK2.OneToMany_Optional3.Max(int? (Level4 xxx) => (int?)xxx.Id) ?? 0)
> 1
}
}
Expand Down
4 changes: 2 additions & 2 deletions test/EFCore.Specification.Tests/Query/Ef6GroupByTestBase.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -360,7 +360,7 @@ public virtual Task Min_Elements_from_LINQ_101(bool async)
ss => from p in ss.Set<ProductForLinq>()
group p by p.Category
into g
let minPrice = g.Min(p => p.UnitPrice)
let minPrice = g.Min(decimal (ProductForLinq p) => p.UnitPrice)
select new { Category = g.Key, CheapestProducts = g.Where(p => p.UnitPrice == minPrice) }));

[ConditionalTheory]
Expand All @@ -383,7 +383,7 @@ public virtual Task Max_Elements_from_LINQ_101(bool async)
ss => from p in ss.Set<ProductForLinq>()
group p by p.Category
into g
let minPrice = g.Max(p => p.UnitPrice)
let minPrice = g.Max(decimal (ProductForLinq p) => p.UnitPrice)
select new { Category = g.Key, MostExpensiveProducts = g.Where(p => p.UnitPrice == minPrice) }));

[ConditionalTheory]
Expand Down
20 changes: 10 additions & 10 deletions test/EFCore.Specification.Tests/Query/NorthwindAggregateOperatorsQueryTestBase.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -139,23 +139,23 @@ public virtual Task Sum_over_subquery(bool async)
=> AssertSum(
async,
ss => ss.Set<Customer>(),
selector: c => c.Orders.Sum(o => o.OrderID));
selector: c => c.Orders.Sum(int (Order o) => o.OrderID));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Sum_over_nested_subquery(bool async)
=> AssertSum(
async,
ss => ss.Set<Customer>(),
selector: c => c.Orders.Sum(o => 5 + o.OrderDetails.Sum(od => od.ProductID)));
selector: c => c.Orders.Sum(int (Order o) => 5 + o.OrderDetails.Sum(int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Sum_over_min_subquery(bool async)
=> AssertSum(
async,
ss => ss.Set<Customer>(),
selector: c => c.Orders.Sum(o => 5 + o.OrderDetails.Min(od => od.ProductID)));
selector: c => c.Orders.Sum(int (Order o) => 5 + o.OrderDetails.Min(int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down Expand Up @@ -270,23 +270,23 @@ public virtual Task Average_over_subquery(bool async)
=> AssertAverage(
async,
ss => ss.Set<Customer>(),
selector: c => c.Orders.Sum(o => o.OrderID));
selector: c => c.Orders.Sum(int (Order o) => o.OrderID));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Average_over_nested_subquery(bool async)
=> AssertAverage(
async,
ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(3),
selector: c => (decimal)c.Orders.Average(o => 5 + o.OrderDetails.Average(od => od.ProductID)));
selector: c => (decimal)c.Orders.Average(double (Order o) => 5 + o.OrderDetails.Average(int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Average_over_max_subquery(bool async)
=> AssertAverage(
async,
ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(3),
selector: c => (decimal)c.Orders.Average(o => 5 + o.OrderDetails.Max(od => od.ProductID)));
selector: c => (decimal)c.Orders.Average(int (Order o) => 5 + o.OrderDetails.Max(int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down Expand Up @@ -447,15 +447,15 @@ public virtual Task Min_over_nested_subquery(bool async)
=> AssertMin(
async,
ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(3),
selector: c => c.Orders.Min(o => 5 + Enumerable.Min(o.OrderDetails, od => od.ProductID)));
selector: c => c.Orders.Min(o => 5 + Enumerable.Min(o.OrderDetails, int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Min_over_max_subquery(bool async)
=> AssertMin(
async,
ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(3),
selector: c => c.Orders.Min(o => 5 + o.OrderDetails.Max(od => od.ProductID)));
selector: c => c.Orders.Min(o => 5 + o.OrderDetails.Max(int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down Expand Up @@ -494,15 +494,15 @@ public virtual Task Max_over_nested_subquery(bool async)
=> AssertMax(
async,
ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(3),
selector: c => c.Orders.Max(o => 5 + Enumerable.Max(o.OrderDetails, od => od.ProductID)));
selector: c => c.Orders.Max(o => 5 + Enumerable.Max(o.OrderDetails, int (OrderDetail od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Max_over_sum_subquery(bool async)
=> AssertMax(
async,
ss => ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(3),
selector: c => c.Orders.Max(o => 5 + o.OrderDetails.Sum(od => od.ProductID)));
selector: c => c.Orders.Max(o => 5 + o.OrderDetails.Sum(int (od) => od.ProductID)));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down
24 changes: 12 additions & 12 deletions test/EFCore.Specification.Tests/Query/NorthwindGroupByQueryTestBase.cs
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Expand Up @@ -37,7 +37,7 @@ public virtual Task GroupBy_Property_Select_Average_with_group_enumerable_projec
async,
ss => ss.Set<Order>().Where(o => o.Customer.City != "London")
.GroupBy(o => o.CustomerID, (k, es) => new { k, es })
.Select(g => g.es.Average(o => o.OrderID))));
.Select(g => g.es.Average(int (Order o) => o.OrderID))));

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down Expand Up @@ -1580,7 +1580,7 @@ into g
{
s.Month,
s.Total,
Payment = ss.Set<Order>().Where(e => e.OrderDate.Value.Month == s.Month).Sum(e => e.OrderID)
Payment = ss.Set<Order>().Where(e => e.OrderDate.Value.Month == s.Month).Sum(int (Order e) => e.OrderID)
},
elementSorter: e => (e.Month, e.Total),
elementAsserter: (e, a) =>
Expand Down Expand Up @@ -1775,7 +1775,7 @@ public virtual Task GroupBy_Aggregate_Join_converted_from_SelectMany(bool async)
ss => from c in ss.Set<Customer>()
from o in ss.Set<Order>().GroupBy(o => o.CustomerID)
.Where(g => g.Count() > 5)
.Select(g => new { CustomerID = g.Key, LastOrderID = g.Max(o => o.OrderID) })
.Select(g => new { CustomerID = g.Key, LastOrderID = g.Max(int (Order o) => o.OrderID) })
.Where(c1 => c.CustomerID == c1.CustomerID)
select c);

Expand All @@ -1787,7 +1787,7 @@ public virtual Task GroupBy_Aggregate_LeftJoin_converted_from_SelectMany(bool as
ss => from c in ss.Set<Customer>()
from o in ss.Set<Order>().GroupBy(o => o.CustomerID)
.Where(g => g.Count() > 5)
.Select(g => new { CustomerID = g.Key, LastOrderID = g.Max(o => o.OrderID) })
.Select(g => new { CustomerID = g.Key, LastOrderID = g.Max(int (Order o) => o.OrderID) })
.Where(c1 => c.CustomerID == c1.CustomerID)
.DefaultIfEmpty()
select c);
Expand Down Expand Up @@ -2342,7 +2342,7 @@ from oc1 in ss.Set<Order>()
.Where(x => x.CustomerID == c.CustomerID).DefaultIfEmpty()
group new { c.CustomerID, oc1.Count } by c.CustomerID
into g
select new { CustomerID = g.Key, Count = g.Sum(x => x.Count) }).Where(x => x.CustomerID == c1.CustomerID)
select new { CustomerID = g.Key, Count = g.Sum(int? (x) => x.Count) }).Where(x => x.CustomerID == c1.CustomerID)
.DefaultIfEmpty()
select new
{
Expand All @@ -2357,7 +2357,7 @@ from oc1 in ss.Set<Order>()
.Where(x => x.CustomerID == c.CustomerID).DefaultIfEmpty()
group new { c.CustomerID, Count = oc1.MaybeScalar(e => e.Count) } by c.CustomerID
into g
select new { CustomerID = g.Key, Count = g.Sum(x => x.Count) }).Where(x => x.CustomerID == c1.CustomerID)
select new { CustomerID = g.Key, Count = g.Sum(int? (x) => x.Count) }).Where(x => x.CustomerID == c1.CustomerID)
.DefaultIfEmpty()
select new
{
Expand Down Expand Up @@ -3200,7 +3200,7 @@ public virtual Task Complex_query_with_groupBy_in_subquery1(bool async)
Subquery = c.Orders
.Select(o => new { First = o.CustomerID, Second = o.OrderID })
.GroupBy(x => x.First)
.Select(g => new { Sum = g.Sum(x => x.Second) }).ToList()
.Select(g => new { Sum = g.Sum(int (x) => x.Second) }).ToList()
}),
elementSorter: e => e.Key,
elementAsserter: (e, a) =>
Expand All @@ -3222,7 +3222,7 @@ public virtual Task Complex_query_with_groupBy_in_subquery2(bool async)
Subquery = c.Orders
.Select(o => new { First = o.CustomerID, Second = o.OrderID })
.GroupBy(x => x.First)
.Select(g => new { Max = g.Max(x => x.First.Length), Sum = g.Sum(x => x.Second) }).ToList()
.Select(g => new { Max = g.Max(int (x) => x.First.Length), Sum = g.Sum(int (x) => x.Second) }).ToList()
}),
elementSorter: e => e.Key,
elementAsserter: (e, a) =>
Expand All @@ -3244,7 +3244,7 @@ public virtual Task Complex_query_with_groupBy_in_subquery3(bool async)
Subquery = ss.Set<Order>()
.Select(o => new { First = o.CustomerID, Second = o.OrderID })
.GroupBy(x => x.First)
.Select(g => new { Max = g.Max(x => x.First.Length), Sum = g.Sum(x => x.Second) }).ToList()
.Select(g => new { Max = g.Max(int (x) => x.First.Length), Sum = g.Sum(int (x) => x.Second) }).ToList()
}),
elementSorter: e => e.Key,
elementAsserter: (e, a) =>
Expand All @@ -3266,7 +3266,7 @@ public virtual Task Complex_query_with_groupBy_in_subquery4(bool async)
Subquery = c.Orders
.Select(o => new { First = o.OrderID, Second = o.Customer.City + o.CustomerID })
.GroupBy(x => x.Second)
.Select(g => new { Sum = g.Sum(x => x.First), Count = g.Count(x => x.Second.StartsWith("Lon")) }).ToList()
.Select(g => new { Sum = g.Sum(int (x) => x.First), Count = g.Count(x => x.Second.StartsWith("Lon")) }).ToList()
}),
elementSorter: e => e.Key,
elementAsserter: (e, a) =>
Expand All @@ -3288,7 +3288,7 @@ into grouping
{
Sum = grouping.Sum(x => x.ProductID + x.OrderID * 1000),
Subquery = (from c in ss.Set<Customer>()
where c.CustomerID.Length < grouping.Min(x => x.OrderID / 100)
where c.CustomerID.Length < grouping.Min(int (OrderDetail x) => x.OrderID / 100)
orderby c.CustomerID
select new { c.CustomerID, c.City }).ToList()
},
Expand Down Expand Up @@ -3381,7 +3381,7 @@ public virtual Task GroupBy_aggregate_from_multiple_query_in_same_projection_2(b
{
g.Key,
A = ss.Set<Employee>().Where(e => e.City == "Seattle").GroupBy(e => e.City)
.Select(g2 => g2.Count() + g.Min(e => e.OrderID))
.Select(g2 => g2.Count() + g.Min(int (Order e) => e.OrderID))
.OrderBy(e => 1)
.FirstOrDefault()
}),
Expand Down
2 changes: 1 addition & 1 deletion test/EFCore.Specification.Tests/Query/NorthwindJoinQueryTestBase.cs
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Expand Up @@ -721,7 +721,7 @@ public virtual Task GroupJoin_aggregate_nested_anonymous_key_selectors(bool asyn
ss.Set<Order>(),
x => new { x.CustomerID, Nested = new { x.City, Year = 1996 } },
x => new { x.CustomerID, Nested = new { City = "London", x.OrderDate.Value.Year } },
(c, g) => new { c.CustomerID, Sum = g.Sum(x => x.CustomerID.Length) }),
(c, g) => new { c.CustomerID, Sum = g.Sum(int (x) => x.CustomerID.Length) }),
elementSorter: e => e.CustomerID));

[ConditionalTheory]
Expand Down
8 changes: 6 additions & 2 deletions test/EFCore.Specification.Tests/Query/NorthwindMiscellaneousQueryTestBase.cs
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Expand Up @@ -1833,6 +1833,7 @@ public virtual Task Where_query_composition3(bool async)
where c1.City == ss.Set<Customer>().OrderBy(c => c.CustomerID).First(c => c.IsLondon).City
select c1));

#pragma warning disable CS9236 // Compiling requires binding the lambda expression at least 200 times
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@roji roji Jul 28, 2025

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/cc @jaredpar @CyrusNajmabadi

Here I got a CS9236, but oddly adding the typing information didn't make it go away (SDK 10.0.100-preview.6.25358.103). A naive attempt at a minimal repro didn't work (see code below). Let me know if there are known false positives like this or how I can help.

Failed attempted repro 
await using var context = new CustomerContext();
await context.Database.EnsureDeletedAsync();
await context.Database.EnsureCreatedAsync();

await AssertTranslationFailed(
    () => AssertQuery(
        async: true,
        ss => from c1 in ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(2)
                where c1.City
                    == (from c2 in ss.Set<Customer>().OrderBy(c => c.CustomerID)
                        // from c3 in ss.Set<Customer>().OrderBy(bool (Customer c) => c.IsLondon).ThenBy(string (Customer c) => c.CustomerID)
                        from c3 in ss.Set<Customer>().OrderBy(c => c.IsLondon).ThenBy(string (Customer c) => c.CustomerID)
                        select new { c3 }).First().c3.City
                select c1));

static Task AssertTranslationFailed(Func<Task> query)
    => throw new NotImplementedException();

Task AssertQuery<TResult>(
        bool async,
        Func<CustomerContext, IQueryable<TResult>> query,
        Func<TResult, object>? elementSorter = null,
        Action<TResult, TResult>? elementAsserter = null,
        bool assertOrder = false,
        bool assertEmpty = false,
        QueryTrackingBehavior? queryTrackingBehavior = null,
        [CallerMemberName] string testMethodName = "")
        => throw new NotImplementedException();

public class CustomerContext : DbContext;

public class Customer
{
    public required string CustomerID { get; set; }
    public required string City { get; set; }
    public bool IsLondon { get; set; }
}

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@CyrusNajmabadi CyrusNajmabadi Jul 28, 2025

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it's possible the outer from/where and the selects are themselves the ones having issues. you may have to write this without linq entirely.

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Where_query_composition4(bool async)
Expand All @@ -1842,9 +1843,10 @@ public virtual Task Where_query_composition4(bool async)
ss => from c1 in ss.Set<Customer>().OrderBy(c => c.CustomerID).Take(2)
where c1.City
== (from c2 in ss.Set<Customer>().OrderBy(c => c.CustomerID)
from c3 in ss.Set<Customer>().OrderBy(c => c.IsLondon).ThenBy(c => c.CustomerID)
from c3 in ss.Set<Customer>().OrderBy(bool (Customer c) => c.IsLondon).ThenBy(string (Customer c) => c.CustomerID)
select new { c3 }).First().c3.City
select c1));
#pragma warning restore CS9236

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down Expand Up @@ -3990,6 +3992,7 @@ public virtual Task Complex_query_with_repeated_query_model_compiles_correctly(b
where customers.Any()
select customers).Any()));

#pragma warning disable CS9236 // Compiling requires binding the lambda expression at least 200 times
[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
public virtual Task Complex_query_with_repeated_nested_query_model_compiles_correctly(bool async)
Expand All @@ -4001,10 +4004,11 @@ public virtual Task Complex_query_with_repeated_nested_query_model_compiles_corr
outer =>
(from c in ss.Set<Customer>()
let customers = ss.Set<Customer>().Where(
cc => ss.Set<Customer>().OrderBy(inner => inner.CustomerID).Take(10).Distinct().Any())
cc => ss.Set<Customer>().OrderBy(string (Customer inner) => inner.CustomerID).Take(10).Distinct().Any())
.Select(cc => cc.CustomerID).ToList()
where customers.Any()
select customers).Any()));
#pragma warning restore CS9236

[ConditionalTheory]
[MemberData(nameof(IsAsyncData))]
Expand Down
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