Skip to content

Allow for specify return value on System.Linq.Enumerable.*OrDefault methods #48886

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 14 commits into from
Mar 18, 2021
Merged

Allow for specify return value on System.Linq.Enumerable.*OrDefault methods #48886

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
14 commits
Select commit Hold shift + click to select a range
b261537
Fix #20064
Feb 28, 2021
41b8091
Add API to ref assembly
Feb 28, 2021
d7e120b
Make overloads with defaultValue not nullable
Mar 2, 2021
2ff34cd
Add unit tests, simplify implementation
Mar 11, 2021
b54edb4
Add LastOrDefault tests
Mar 11, 2021
ed55a24
Add Queryable tests
Mar 11, 2021
fa5bc80
Additional tests. Reformatting TryGet Methods.
Mar 11, 2021
8082459
Update src/libraries/System.Linq.Queryable/tests/FirstOrDefaultTests.cs
eiriktsarpalis Mar 12, 2021
24cf263
Apply suggestions from code review
Mar 14, 2021
ed9728d
Fix ref methods
Mar 15, 2021
604ee59
Further adjust nullability
Mar 16, 2021
5a05802
Fix more nullables
Mar 16, 2021
9e8699e
fix failing tests
eiriktsarpalis Mar 17, 2021
9499df6
Restore coding style
Mar 17, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 6 additions & 0 deletions src/libraries/System.Linq.Queryable/ref/System.Linq.Queryable.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -86,7 +86,9 @@ public static partial class Queryable
public static System.Linq.IQueryable<TSource> Except<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2) { throw null; }
public static System.Linq.IQueryable<TSource> Except<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2, System.Collections.Generic.IEqualityComparer<TSource>? comparer) { throw null; }
public static TSource? FirstOrDefault<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
public static TSource FirstOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, TSource defaultValue) { throw null; }
public static TSource? FirstOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
public static TSource FirstOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate, TSource defaultValue) { throw null; }
public static TSource First<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
public static TSource First<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
public static System.Linq.IQueryable<System.Linq.IGrouping<TKey, TSource>> GroupBy<TSource, TKey>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, TKey>> keySelector) { throw null; }
Expand All @@ -104,7 +106,9 @@ public static partial class Queryable
public static System.Linq.IQueryable<TResult> Join<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter, TInner, TResult>> resultSelector) { throw null; }
public static System.Linq.IQueryable<TResult> Join<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter, TInner, TResult>> resultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
public static TSource? LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
public static TSource LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, TSource defaultValue) { throw null; }
public static TSource? LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
public static TSource LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate, TSource defaultValue) { throw null; }
public static TSource Last<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
public static TSource Last<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
public static long LongCount<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
Expand All @@ -129,7 +133,9 @@ public static partial class Queryable
public static bool SequenceEqual<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2) { throw null; }
public static bool SequenceEqual<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2, System.Collections.Generic.IEqualityComparer<TSource>? comparer) { throw null; }
public static TSource? SingleOrDefault<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
public static TSource SingleOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, TSource defaultValue) { throw null; }
public static TSource? SingleOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
public static TSource SingleOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate, TSource defaultValue) { throw null; }
public static TSource Single<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
public static TSource Single<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
public static System.Linq.IQueryable<TSource> SkipLast<TSource>(this System.Linq.IQueryable<TSource> source, int count) { throw null; }
Expand Down
42 changes: 42 additions & 0 deletions src/libraries/System.Linq.Queryable/src/System/Linq/CachedReflection.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -284,6 +284,20 @@ public static MethodInfo FirstOrDefault_TSource_2(Type TSource) =>
(s_FirstOrDefault_TSource_2 ??= new Func<IQueryable<object>, Expression<Func<object, bool>>, object?>(Queryable.FirstOrDefault).GetMethodInfo().GetGenericMethodDefinition())
.MakeGenericMethod(TSource);

private static MethodInfo? s_FirstOrDefault_TSource_3;

public static MethodInfo FirstOrDefault_TSource_3(Type TSource) =>
(s_FirstOrDefault_TSource_3 ??
(s_FirstOrDefault_TSource_3 = new Func<IQueryable<object>, object, object>(Queryable.FirstOrDefault).GetMethodInfo().GetGenericMethodDefinition()))
.MakeGenericMethod(TSource);

private static MethodInfo? s_FirstOrDefault_TSource_4;

public static MethodInfo FirstOrDefault_TSource_4(Type TSource) =>
(s_FirstOrDefault_TSource_4 ??
(s_FirstOrDefault_TSource_4 = new Func<IQueryable<object>, Expression<Func<object, bool>>, object, object>(Queryable.FirstOrDefault).GetMethodInfo().GetGenericMethodDefinition()))
.MakeGenericMethod(TSource);

private static MethodInfo? s_GroupBy_TSource_TKey_2;

public static MethodInfo GroupBy_TSource_TKey_2(Type TSource, Type TKey) =>
Expand Down Expand Up @@ -392,6 +406,20 @@ public static MethodInfo LastOrDefault_TSource_2(Type TSource) =>
(s_LastOrDefault_TSource_2 ??= new Func<IQueryable<object>, Expression<Func<object, bool>>, object?>(Queryable.LastOrDefault).GetMethodInfo().GetGenericMethodDefinition())
.MakeGenericMethod(TSource);

private static MethodInfo? s_LastOrDefault_TSource_3;

public static MethodInfo LastOrDefault_TSource_3(Type TSource) =>
(s_LastOrDefault_TSource_3 ??
(s_LastOrDefault_TSource_3 = new Func<IQueryable<object>, object, object>(Queryable.LastOrDefault).GetMethodInfo().GetGenericMethodDefinition()))
.MakeGenericMethod(TSource);

private static MethodInfo? s_LastOrDefault_TSource_4;

public static MethodInfo LastOrDefault_TSource_4(Type TSource) =>
(s_LastOrDefault_TSource_4 ??
(s_LastOrDefault_TSource_4 = new Func<IQueryable<object>, Expression<Func<object, bool>>, object, object>(Queryable.LastOrDefault).GetMethodInfo().GetGenericMethodDefinition()))
.MakeGenericMethod(TSource);

private static MethodInfo? s_LongCount_TSource_1;

public static MethodInfo LongCount_TSource_1(Type TSource) =>
Expand Down Expand Up @@ -536,6 +564,20 @@ public static MethodInfo SingleOrDefault_TSource_2(Type TSource) =>
(s_SingleOrDefault_TSource_2 ??= new Func<IQueryable<object>, Expression<Func<object, bool>>, object?>(Queryable.SingleOrDefault).GetMethodInfo().GetGenericMethodDefinition())
.MakeGenericMethod(TSource);

private static MethodInfo? s_SingleOrDefault_TSource_3;

public static MethodInfo SingleOrDefault_TSource_3(Type TSource) =>
(s_SingleOrDefault_TSource_3 ??
(s_SingleOrDefault_TSource_3 = new Func<IQueryable<object>, object, object>(Queryable.SingleOrDefault).GetMethodInfo().GetGenericMethodDefinition()))
.MakeGenericMethod(TSource);

private static MethodInfo? s_SingleOrDefault_TSource_4;

public static MethodInfo SingleOrDefault_TSource_4(Type TSource) =>
(s_SingleOrDefault_TSource_4 ??
(s_SingleOrDefault_TSource_4 = new Func<IQueryable<object>, Expression<Func<object, bool>>, object, object>(Queryable.SingleOrDefault).GetMethodInfo().GetGenericMethodDefinition()))
.MakeGenericMethod(TSource);

private static MethodInfo? s_Skip_TSource_2;

public static MethodInfo Skip_TSource_2(Type TSource) =>
Expand Down
82 changes: 82 additions & 0 deletions src/libraries/System.Linq.Queryable/src/System/Linq/Queryable.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -864,6 +864,18 @@ public static TSource First<TSource>(this IQueryable<TSource> source, Expression
CachedReflectionInfo.FirstOrDefault_TSource_1(typeof(TSource)), source.Expression));
}

[DynamicDependency("FirstOrDefault`1", typeof(Enumerable))]
public static TSource FirstOrDefault<TSource>(this IQueryable<TSource> source, TSource defaultValue)
{
if (source == null)
throw Error.ArgumentNull(nameof(source));
return source.Provider.Execute<TSource>(
Expression.Call(
null,
CachedReflectionInfo.FirstOrDefault_TSource_3(typeof(TSource)),
source.Expression, Expression.Constant(defaultValue, typeof(TSource))));
}

[DynamicDependency("FirstOrDefault`1", typeof(Enumerable))]
public static TSource? FirstOrDefault<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
{
Expand All @@ -879,6 +891,21 @@ public static TSource First<TSource>(this IQueryable<TSource> source, Expression
));
}

[DynamicDependency("FirstOrDefault`1", typeof(Enumerable))]
public static TSource FirstOrDefault<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate, TSource defaultValue)
{
if (source == null)
throw Error.ArgumentNull(nameof(source));
if (predicate == null)
throw Error.ArgumentNull(nameof(predicate));
return source.Provider.Execute<TSource>(
Expression.Call(
null,
CachedReflectionInfo.FirstOrDefault_TSource_4(typeof(TSource)),
source.Expression, Expression.Quote(predicate), Expression.Constant(defaultValue, typeof(TSource))
));
}

[DynamicDependency("Last`1", typeof(Enumerable))]
public static TSource Last<TSource>(this IQueryable<TSource> source)
{
Expand Down Expand Up @@ -916,6 +943,18 @@ public static TSource Last<TSource>(this IQueryable<TSource> source, Expression<
CachedReflectionInfo.LastOrDefault_TSource_1(typeof(TSource)), source.Expression));
}

[DynamicDependency("LastOrDefault`1", typeof(Enumerable))]
public static TSource LastOrDefault<TSource>(this IQueryable<TSource> source, TSource defaultValue)
{
if (source == null)
throw Error.ArgumentNull(nameof(source));
return source.Provider.Execute<TSource>(
Expression.Call(
null,
CachedReflectionInfo.LastOrDefault_TSource_3(typeof(TSource)),
source.Expression, Expression.Constant(defaultValue, typeof(TSource))));
}

[DynamicDependency("LastOrDefault`1", typeof(Enumerable))]
public static TSource? LastOrDefault<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
{
Expand All @@ -931,6 +970,21 @@ public static TSource Last<TSource>(this IQueryable<TSource> source, Expression<
));
}

[DynamicDependency("LastOrDefault`1", typeof(Enumerable))]
public static TSource LastOrDefault<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate, TSource defaultValue)
{
if (source == null)
throw Error.ArgumentNull(nameof(source));
if (predicate == null)
throw Error.ArgumentNull(nameof(predicate));
return source.Provider.Execute<TSource>(
Expression.Call(
null,
CachedReflectionInfo.LastOrDefault_TSource_4(typeof(TSource)),
source.Expression, Expression.Quote(predicate), Expression.Constant(defaultValue, typeof(TSource))
));
}

[DynamicDependency("Single`1", typeof(Enumerable))]
public static TSource Single<TSource>(this IQueryable<TSource> source)
{
Expand Down Expand Up @@ -968,6 +1022,19 @@ public static TSource Single<TSource>(this IQueryable<TSource> source, Expressio
CachedReflectionInfo.SingleOrDefault_TSource_1(typeof(TSource)), source.Expression));
}

[DynamicDependency("SingleOrDefault`1", typeof(Enumerable))]
public static TSource SingleOrDefault<TSource>(this IQueryable<TSource> source, TSource defaultValue)
{
if (source == null)
throw Error.ArgumentNull(nameof(source));
return source.Provider.Execute<TSource>(
Expression.Call(
null,
CachedReflectionInfo.SingleOrDefault_TSource_3(typeof(TSource)),
source.Expression, Expression.Constant(defaultValue, typeof(TSource))));

}

[DynamicDependency("SingleOrDefault`1", typeof(Enumerable))]
public static TSource? SingleOrDefault<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
{
Expand All @@ -983,6 +1050,21 @@ public static TSource Single<TSource>(this IQueryable<TSource> source, Expressio
));
}

[DynamicDependency("SingleOrDefault`1", typeof(Enumerable))]
public static TSource SingleOrDefault<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate, TSource defaultValue)
{
if (source == null)
throw Error.ArgumentNull(nameof(source));
if (predicate == null)
throw Error.ArgumentNull(nameof(predicate));
return source.Provider.Execute<TSource>(
Expression.Call(
null,
CachedReflectionInfo.SingleOrDefault_TSource_4(typeof(TSource)),
source.Expression, Expression.Quote(predicate), Expression.Constant(defaultValue, typeof(TSource))
));
}

[DynamicDependency("ElementAt`1", typeof(Enumerable))]
public static TSource ElementAt<TSource>(this IQueryable<TSource> source, int index)
{
Expand Down
46 changes: 46 additions & 0 deletions src/libraries/System.Linq.Queryable/tests/FirstOrDefaultTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,15 @@ public void Empty()
Assert.Equal(0, source.AsQueryable().FirstOrDefault());
}

[Fact]
public void EmptyDefault()
{
int[] source = { };
int defaultValue = 5;

Assert.Equal(defaultValue, source.AsQueryable().FirstOrDefault(defaultValue));
}

[Fact]
public void ManyElementsFirstIsDefault()
{
Expand All @@ -37,37 +46,74 @@ public void OneElementTruePredicate()
Assert.Equal(4, source.AsQueryable().FirstOrDefault(i => i % 2 == 0));
}

[Fact]
public void OneElementTruePredicateDefault()
{
int[] source = { 4 };
Assert.Equal(4, source.AsQueryable().FirstOrDefault(i => i % 2 == 0, 5));
}

[Fact]
public void OneElementFalsePredicate()
{
int[] source = { 3 };
Assert.Equal(0, source.AsQueryable().FirstOrDefault(i => i % 2 == 0));
}

[Fact]
public void OneElementFalsePredicateDefault()
{
int[] source = { 3 };
Assert.Equal(5, source.AsQueryable().FirstOrDefault(i => i % 2 == 0, 5));
}

[Fact]
public void ManyElementsPredicateFalseForAll()
{
int[] source = { 9, 5, 1, 3, 17, 21 };
Assert.Equal(0, source.AsQueryable().FirstOrDefault(i => i % 2 == 0));
}

[Fact]
public void ManyElementsPredicateFalseForAllDefault()
{
int[] source = { 9, 5, 1, 3, 17, 21 };
Assert.Equal(2, source.AsQueryable().FirstOrDefault(i => i % 2 == 0, 2));
}

[Fact]
public void PredicateTrueForSome()
{
int[] source = { 3, 7, 10, 7, 9, 2, 11, 17, 13, 8 };
Assert.Equal(10, source.AsQueryable().FirstOrDefault(i => i % 2 == 0));
}
[Fact]
public void PredicateTrueForSomeDefault()
{
int[] source = { 3, 7, 10, 7, 9, 2, 11, 17, 13, 8 };
Assert.Equal(10, source.AsQueryable().FirstOrDefault(i => i % 2 == 0, 5));
}

[Fact]
public void NullSource()
{
AssertExtensions.Throws<ArgumentNullException>("source", () => ((IQueryable<int>)null).FirstOrDefault());
AssertExtensions.Throws<ArgumentNullException>("source", () => ((IQueryable<int>)null).FirstOrDefault(5));
}

[Fact]
public void NullSourcePredicateUsed()
{
AssertExtensions.Throws<ArgumentNullException>("source", () => ((IQueryable<int>)null).FirstOrDefault(i => i != 2));
AssertExtensions.Throws<ArgumentNullException>("source", () => ((IQueryable<int>)null).FirstOrDefault(i => i != 2, 5));
}

[Fact]
public void NullPredicate()
{
Expression<Func<int, bool>> predicate = null;
AssertExtensions.Throws<ArgumentNullException>("predicate", () => Enumerable.Range(0, 3).AsQueryable().FirstOrDefault(predicate));
AssertExtensions.Throws<ArgumentNullException>("predicate", () => Enumerable.Range(0, 3).AsQueryable().FirstOrDefault(predicate, 5));
}

[Fact]
Expand Down
15 changes: 15 additions & 0 deletions src/libraries/System.Linq.Queryable/tests/LastOrDefaultTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,13 +14,28 @@ public void Empty()
Assert.Null(Enumerable.Empty<int?>().AsQueryable().LastOrDefault());
}

[Fact]
public void EmptyDefault()
{
int[] source = { };
int defaultValue = 5;
Assert.Equal(defaultValue, source.AsQueryable().LastOrDefault(defaultValue));
}

[Fact]
public void OneElement()
{
int[] source = { 5 };
Assert.Equal(5, source.AsQueryable().LastOrDefault());
}

[Fact]
public void OneElementFalsePredicate()
{
int[] source = { 3 };
Assert.Equal(5, source.AsQueryable().LastOrDefault(i => i % 2 == 0, 5));
}

[Fact]
public void ManyElementsLastIsDefault()
{
Expand Down
14 changes: 14 additions & 0 deletions src/libraries/System.Linq.Queryable/tests/SingleOrDefaultTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,12 +22,26 @@ public void Empty()
Assert.Null(Enumerable.Empty<int?>().AsQueryable().SingleOrDefault());
}

[Fact]
public void EmptyDefault()
{
int[] source = { };
int defaultValue = 5;
Assert.Equal(defaultValue, source.AsQueryable().SingleOrDefault(5));
}

[Fact]
public void EmptySourceWithPredicate()
{
Assert.Null(Enumerable.Empty<int?>().AsQueryable().SingleOrDefault(i => i % 2 == 0));
}

[Fact]
public void EmptySourceWithPredicateDefault()
{
Assert.Equal(5, Enumerable.Empty<int?>().AsQueryable().SingleOrDefault(i => i % 2 == 0, 5));
}

[Theory]
[InlineData(1, 100)]
[InlineData(42, 100)]
Expand Down
Loading