Implement ToImmutable*Async extension methods

Ix.NET/Source/System.Linq.Async.SourceGenerator/AsyncOverloadsGenerator.cs

@@ -52,28 +52,21 @@ private static IEnumerable<AsyncMethodGrouping> GetMethodsGroupedBySyntaxTree(Ge
 
         private static string GenerateOverloads(AsyncMethodGrouping grouping, GenerationOptions options)
         {
-            var usings = grouping.SyntaxTree.GetRoot() is CompilationUnitSyntax compilationUnit
-                ? compilationUnit.Usings.ToString()
-                : string.Empty;
-
-            var overloads = new StringBuilder();
-            overloads.AppendLine("#nullable enable");
-            overloads.AppendLine(usings);
-            overloads.AppendLine("namespace System.Linq");
-            overloads.AppendLine("{");
-            overloads.AppendLine("    partial class AsyncEnumerable");
-            overloads.AppendLine("    {");
-
-            foreach (var method in grouping.Methods)
-                overloads.AppendLine(GenerateOverload(method, options));
-
-            overloads.AppendLine("    }");
-            overloads.AppendLine("}");
-
-            return overloads.ToString();
+            var compilationRoot = grouping.SyntaxTree.GetCompilationUnitRoot();
+            var namespaceDeclaration = compilationRoot.ChildNodes().OfType<NamespaceDeclarationSyntax>().Single();
+            var classDeclaration = namespaceDeclaration.ChildNodes().OfType<ClassDeclarationSyntax>().Single();
+
+            return CompilationUnit()
+                .WithUsings(List(compilationRoot.Usings.Select(@using => @using.WithoutTrivia())))
+                .AddMembers(NamespaceDeclaration(namespaceDeclaration.Name)
+                    .AddMembers(ClassDeclaration(classDeclaration.Identifier)
+                        .AddModifiers(Token(SyntaxKind.PartialKeyword))
+                        .WithMembers(List(grouping.Methods.Select(method => GenerateOverload(method, options))))))
+                .NormalizeWhitespace()
+                .ToFullString();
         }
 
-        private static string GenerateOverload(AsyncMethod method, GenerationOptions options)
+        private static MemberDeclarationSyntax GenerateOverload(AsyncMethod method, GenerationOptions options)
             => MethodDeclaration(method.Syntax.ReturnType, GetMethodName(method.Symbol, options))
                 .WithModifiers(TokenList(Token(SyntaxKind.PublicKeyword), Token(SyntaxKind.StaticKeyword)))
                 .WithTypeParameterList(method.Syntax.TypeParameterList)
@@ -87,9 +80,7 @@ private static string GenerateOverload(AsyncMethod method, GenerationOptions opt
                                 method.Syntax.ParameterList.Parameters
                                     .Select(p => Argument(IdentifierName(p.Identifier))))))))
                 .WithSemicolonToken(Token(SyntaxKind.SemicolonToken))
-                .WithLeadingTrivia(method.Syntax.GetLeadingTrivia().Where(t => t.GetStructure() is not DirectiveTriviaSyntax))
-                .NormalizeWhitespace()
-                .ToFullString();
+                .WithLeadingTrivia(method.Syntax.GetLeadingTrivia().Where(t => t.GetStructure() is not DirectiveTriviaSyntax));
 
         private static INamedTypeSymbol GetAsyncOverloadAttributeSymbol(GeneratorExecutionContext context)
             => context.Compilation.GetTypeByMetadataName("System.Linq.GenerateAsyncOverloadAttribute") ?? throw new InvalidOperationException();

Ix.NET/Source/System.Linq.Async.Tests/System/Collections/Immutable/ToImmutableArray.cs

@@ -0,0 +1,84 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Tests
+{
+    public class ToImmutableArray : AsyncEnumerableTests
+    {
+        [Fact]
+        public async Task ToImmutableArray_Null()
+        {
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableArrayAsyncEnumerableExtensions.ToImmutableArrayAsync<int>(default).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableArrayAsyncEnumerableExtensions.ToImmutableArrayAsync<int>(default, CancellationToken.None).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_IAsyncIListProvider_Simple()
+        {
+            var xs = new[] { 42, 25, 39 };
+            var res = xs.ToAsyncEnumerable().ToImmutableArrayAsync();
+            Assert.True((await res).SequenceEqual(xs));
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_IAsyncIListProvider_Empty1()
+        {
+            var xs = new int[0];
+            var res = xs.ToAsyncEnumerable().ToImmutableArrayAsync();
+            Assert.True((await res).SequenceEqual(xs));
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_IAsyncIListProvider_Empty2()
+        {
+            var xs = new HashSet<int>();
+            var res = xs.ToAsyncEnumerable().ToImmutableArrayAsync();
+            Assert.True((await res).SequenceEqual(xs));
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_Empty()
+        {
+            var xs = AsyncEnumerable.Empty<int>();
+            var res = xs.ToImmutableArrayAsync();
+            Assert.True((await res).Length == 0);
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_Throw()
+        {
+            var ex = new Exception("Bang!");
+            var res = Throw<int>(ex).ToImmutableArrayAsync();
+            await AssertThrowsAsync(res, ex);
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_Query()
+        {
+            var xs = await AsyncEnumerable.Range(5, 50).Take(10).ToImmutableArrayAsync();
+            var ex = new[] { 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 };
+
+            Assert.True(ex.SequenceEqual(xs));
+        }
+
+        [Fact]
+        public async Task ToImmutableArray_Set()
+        {
+            var res = new[] { 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 };
+            var xs = new HashSet<int>(res);
+
+            var arr = await xs.ToAsyncEnumerable().ToImmutableArrayAsync();
+
+            Assert.True(res.SequenceEqual(arr));
+        }
+    }
+}

Ix.NET/Source/System.Linq.Async.Tests/System/Collections/Immutable/ToImmutableDictionary.cs

@@ -0,0 +1,113 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Tests
+{
+    public class ToImmutableDictionary : AsyncEnumerableTests
+    {
+        [Fact]
+        public async Task ToImmutableDictionary_Null()
+        {
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int>(default, x => 0).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync(Return42, default(Func<int, int>)).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int>(default, x => 0, EqualityComparer<int>.Default).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync(Return42, default, EqualityComparer<int>.Default).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(default, x => 0, x => 0).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(Return42, default, x => 0).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(Return42, x => 0, default).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(default, x => 0, x => 0, EqualityComparer<int>.Default).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync(Return42, default, x => 0, EqualityComparer<int>.Default).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(Return42, x => 0, default, EqualityComparer<int>.Default).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int>(default, x => 0, CancellationToken.None).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync(Return42, default(Func<int, int>), CancellationToken.None).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int>(default, x => 0, EqualityComparer<int>.Default, CancellationToken.None).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync(Return42, default, EqualityComparer<int>.Default, CancellationToken.None).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(default, x => 0, x => 0, CancellationToken.None).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(Return42, default, x => 0, CancellationToken.None).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(Return42, x => 0, default, CancellationToken.None).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(default, x => 0, x => 0, EqualityComparer<int>.Default, CancellationToken.None).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync(Return42, default, x => 0, EqualityComparer<int>.Default, CancellationToken.None).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableDictionaryAsyncEnumerableExtensions.ToImmutableDictionaryAsync<int, int, int>(Return42, x => 0, default, EqualityComparer<int>.Default, CancellationToken.None).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary1Async()
+        {
+            var xs = new[] { 1, 4 }.ToAsyncEnumerable();
+            var res = await xs.ToImmutableDictionaryAsync(x => x % 2);
+            Assert.True(res[0] == 4);
+            Assert.True(res[1] == 1);
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary2Async()
+        {
+            var xs = new[] { 1, 4, 2 }.ToAsyncEnumerable();
+            await AssertThrowsAsync<ArgumentException>(xs.ToImmutableDictionaryAsync(x => x % 2).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary3Async()
+        {
+            var xs = new[] { 1, 4 }.ToAsyncEnumerable();
+            var res = await xs.ToImmutableDictionaryAsync(x => x % 2, x => x + 1);
+            Assert.True(res[0] == 5);
+            Assert.True(res[1] == 2);
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary4Async()
+        {
+            var xs = new[] { 1, 4, 2 }.ToAsyncEnumerable();
+            await AssertThrowsAsync<ArgumentException>(xs.ToImmutableDictionaryAsync(x => x % 2, x => x + 1).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary5Async()
+        {
+            var xs = new[] { 1, 4 }.ToAsyncEnumerable();
+            var res = await xs.ToImmutableDictionaryAsync(x => x % 2, new Eq());
+            Assert.True(res[0] == 4);
+            Assert.True(res[1] == 1);
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary6Async()
+        {
+            var xs = new[] { 1, 4, 2 }.ToAsyncEnumerable();
+            await AssertThrowsAsync<ArgumentException>(xs.ToImmutableDictionaryAsync(x => x % 2, new Eq()).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableDictionary7Async()
+        {
+            var xs = new[] { 1, 4 }.ToAsyncEnumerable();
+            var res = await xs.ToImmutableDictionaryAsync(x => x % 2, x => x, new Eq());
+            Assert.True(res[0] == 4);
+            Assert.True(res[1] == 1);
+        }
+
+        private sealed class Eq : IEqualityComparer<int>
+        {
+            public bool Equals(int x, int y) => EqualityComparer<int>.Default.Equals(Math.Abs(x), Math.Abs(y));
+
+            public int GetHashCode(int obj) => EqualityComparer<int>.Default.GetHashCode(Math.Abs(obj));
+        }
+    }
+}

Ix.NET/Source/System.Linq.Async.Tests/System/Collections/Immutable/ToImmutableHashSet.cs

@@ -0,0 +1,49 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Tests
+{
+    public class ToImmutableHashSet : AsyncEnumerableTests
+    {
+        [Fact]
+        public async Task ToImmutableHashSet_Null()
+        {
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableHashSetAsyncEnumerableExtensions.ToImmutableHashSetAsync<int>(default).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableHashSetAsyncEnumerableExtensions.ToImmutableHashSetAsync<int>(default, CancellationToken.None).AsTask());
+
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableHashSetAsyncEnumerableExtensions.ToImmutableHashSetAsync(default, EqualityComparer<int>.Default, CancellationToken.None).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableHashSet_Simple()
+        {
+            var xs = new[] { 1, 2, 1, 2, 3, 4, 1, 2, 3, 4 };
+            var res = xs.ToAsyncEnumerable().ToImmutableHashSetAsync();
+            Assert.True((await res).OrderBy(x => x).SequenceEqual(new[] { 1, 2, 3, 4 }));
+        }
+
+        [Fact]
+        public async Task ToImmutableHashSet_Comparer()
+        {
+            var xs = new[] { 1, 12, 11, 2, 3, 14, 1, 12, 13, 4 };
+            var res = xs.ToAsyncEnumerable().ToImmutableHashSetAsync(new Eq());
+            Assert.True((await res).OrderBy(x => x).SequenceEqual(new[] { 1, 3, 12, 14 }));
+        }
+
+        private class Eq : IEqualityComparer<int>
+        {
+            public bool Equals(int x, int y) => x % 10 == y % 10;
+
+            public int GetHashCode(int obj) => obj % 10;
+        }
+    }
+}

Ix.NET/Source/System.Linq.Async.Tests/System/Collections/Immutable/ToImmutableList.cs

@@ -0,0 +1,47 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Tests
+{
+    public class ToImmutableList : AsyncEnumerableTests
+    {
+        [Fact]
+        public async Task ToImmutableList_Null()
+        {
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableListAsyncEnumerableExtensions.ToImmutableListAsync<int>(default).AsTask());
+            await Assert.ThrowsAsync<ArgumentNullException>(() => ImmutableListAsyncEnumerableExtensions.ToImmutableListAsync<int>(default, CancellationToken.None).AsTask());
+        }
+
+        [Fact]
+        public async Task ToImmutableList_Simple()
+        {
+            var xs = new[] { 42, 25, 39 };
+            var res = xs.ToAsyncEnumerable().ToImmutableListAsync();
+            Assert.True((await res).SequenceEqual(xs));
+        }
+
+        [Fact]
+        public async Task ToImmutableList_Empty()
+        {
+            var xs = AsyncEnumerable.Empty<int>();
+            var res = xs.ToImmutableListAsync();
+            Assert.True((await res).Count == 0);
+        }
+
+        [Fact]
+        public async Task ToImmutableList_Throw()
+        {
+            var ex = new Exception("Bang!");
+            var res = Throw<int>(ex).ToImmutableListAsync();
+            await AssertThrowsAsync(res, ex);
+        }
+    }
+}