RemoveAsyncModifierTests.cs

// 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.Threading.Tasks;
using Microsoft.CodeAnalysis.CSharp.RemoveAsyncModifier;
using Microsoft.CodeAnalysis.CSharp.Test.Utilities;
using Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions;
using Microsoft.CodeAnalysis.Test.Utilities;
using Microsoft.CodeAnalysis.Testing;
using Roslyn.Test.Utilities;
using Xunit;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.RemoveAsyncModifier;
 
using VerifyCS = CSharpCodeFixVerifier<
    CSharpRemoveUnnecessaryAsyncModifierDiagnosticAnalyzer,
    CSharpRemoveAsyncModifierCodeFixProvider>;
 
[Trait(Traits.Feature, Traits.Features.CodeActionsRemoveAsyncModifier)]
public sealed class RemoveAsyncModifierTests
{
    [Fact]
    public Task Method_Task_MultipleAndNested()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo()
                {
                    if (DateTime.Now.Ticks > 0)
                    {
                        return;
                    }
                }
 
                {|IDE0390:async|} Task Foo()
                {
                    Console.WriteLine(1);
                }
 
                {|IDE0390:async|} Task Bar()
                {
                    {|IDE0390:async|} Task Baz()
                    {
                        Func<Task<int>> g = {|IDE0390:async|} () => 5;
                    }
                }
 
                {|IDE0390:async|} Task<string> Tur()
                {
                    {|IDE0390:async|} Task<string> Duck()
                    {
                        {|IDE0390:async|} Task<string> En()
                        {
                            return "Developers!";
                        }
 
                        return "Developers! Developers!";
                    }
 
                    return "Developers! Developers! Developers!";
                }
 
                {|IDE0390:async|} Task Nurk()
                {
                    Func<Task<int>> f = {|IDE0390:async|} () => 4;
 
                    if (DateTime.Now.Ticks > f().Result)
                    {
                    }
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    if (DateTime.Now.Ticks > 0)
                    {
                        return Task.CompletedTask;
                    }
 
                    return Task.CompletedTask;
                }
 
                Task Foo()
                {
                    Console.WriteLine(1);
                    return Task.CompletedTask;
                }
 
                Task Bar()
                {
                    Task Baz()
                    {
                        Func<Task<int>> g = () => Task.FromResult(5);
                        return Task.CompletedTask;
                    }
 
                    return Task.CompletedTask;
                }
 
                Task<string> Tur()
                {
                    Task<string> Duck()
                    {
                        Task<string> En()
                        {
                            return Task.FromResult("Developers!");
                        }
 
                        return Task.FromResult("Developers! Developers!");
                    }
 
                    return Task.FromResult("Developers! Developers! Developers!");
                }
 
                Task Nurk()
                {
                    Func<Task<int>> f = () => Task.FromResult(4);
 
                    if (DateTime.Now.Ticks > f().Result)
                    {
                    }
 
                    return Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task Method_Task_EmptyBlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo(){}
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    return Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task Method_Task_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return;
                    }
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return Task.CompletedTask;
                    }
 
                    return Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task Method_ValueTask_BlockBody()
        => new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} ValueTask Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return;
                    }
                }
            }
            """,
            FixedCode = """
            using System.Threading.Tasks;
 
            class C
            {
                ValueTask Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return new ValueTask();
                    }
 
                    return new ValueTask();
                }
            }
            """,
        }.RunAsync();
 
    [Fact]
    public Task Method_ValueTaskOfT_BlockBody()
        => new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} ValueTask<int> Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return 2;
                    }
 
                    return 3;
                }
            }
            """,
            FixedCode = """
            using System.Threading.Tasks;
 
            class C
            {
                ValueTask<int> Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return new ValueTask<int>(2);
                    }
 
                    return new ValueTask<int>(3);
                }
            }
            """,
        }.RunAsync();
 
    [Fact]
    public Task Method_ValueTask_ExpressionBody()
        => new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} ValueTask Goo() => System.Console.WriteLine(1);
            }
            """,
            FixedCode = """
            using System.Threading.Tasks;
 
            class C
            {
                ValueTask Goo()
                {
                    System.Console.WriteLine(1);
                    return new ValueTask();
                }
            }
            """,
        }.RunAsync();
 
    [Fact]
    public Task Method_ValueTaskOfT_ExpressionBody()
        => new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} ValueTask<int> Goo() => 3;
            }
            """,
            FixedCode = """
            using System.Threading.Tasks;
 
            class C
            {
                ValueTask<int> Goo() => new ValueTask<int>(3);
            }
            """,
        }.RunAsync();
 
    [Fact]
    public Task Method_Task_BlockBody_Throws()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return;
                    }
 
                    throw new System.ApplicationException();
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return Task.CompletedTask;
                    }
 
                    throw new System.ApplicationException();
                }
            }
            """);
 
    [Fact]
    public Task Method_Task_BlockBody_WithLocalFunction()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo()
                {
                    if (GetTicks() > 0)
                    {
                        return;
                    }
 
                    long GetTicks()
                    {
                        return System.DateTime.Now.Ticks;
                    }
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    if (GetTicks() > 0)
                    {
                        return Task.CompletedTask;
                    }
 
                    long GetTicks()
                    {
                        return System.DateTime.Now.Ticks;
                    }
 
                    return Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task Method_Task_BlockBody_WithLambda()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo()
                {
                    System.Func<long> getTicks = () => {
                        return System.DateTime.Now.Ticks;
                    };
 
                    if (getTicks() > 0)
                    {
                        return;
                    }
 
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    System.Func<long> getTicks = () => {
                        return System.DateTime.Now.Ticks;
                    };
 
                    if (getTicks() > 0)
                    {
                        return Task.CompletedTask;
                    }
 
                    return Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task Method_TaskOfT_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task<int> Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return 2;
                    }
 
                    return 3;
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task<int> Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return Task.FromResult(2);
                    }
 
                    return Task.FromResult(3);
                }
            }
            """);
 
    [Fact]
    public Task Method_TaskOfT_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task<int> Goo() => 2;
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                Task<int> Goo() => Task.FromResult(2);
            }
            """);
 
    [Fact]
    public Task Method_Task_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} Task Goo() => Console.WriteLine("Hello");
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                Task Goo()
                {
                    Console.WriteLine("Hello");
                    return Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task LocalFunction_Task_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    {|IDE0390:async|} Task Goo()
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return;
                        }
                    }
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Task Goo()
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return Task.CompletedTask;
                        }
 
                        return Task.CompletedTask;
                    }
                }
            }
            """);
 
    [Fact]
    public Task LocalFunction_Task_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    {|IDE0390:async|} Task Goo() => Console.WriteLine(1);
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Task Goo() { Console.WriteLine(1); return Task.CompletedTask; }
                }
            }
            """);
 
    [Fact]
    public Task LocalFunction_TaskOfT_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    {|IDE0390:async|} Task<int> Goo()
                    {
                        return 1;
                    }
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Task<int> Goo()
                    {
                        return Task.FromResult(1);
                    }
                }
            }
            """);
 
    [Fact]
    public Task LocalFunction_TaskOfT_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    {|IDE0390:async|} Task<int> Goo() => 1;
                }
            }
            """,
            """
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Task<int> Goo() => Task.FromResult(1);
                }
            }
            """);
 
    [Fact]
    public Task AnonymousFunction_Task_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task> foo = (Func<Task>){|IDE0390:async|} delegate {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return;
                        }
                    };
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task> foo = (Func<Task>)delegate
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return Task.CompletedTask;
                        }
 
                        return Task.CompletedTask;
                    };
                }
            }
            """);
 
    [Fact]
    public Task AnonymousFunction_TaskOfT_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task<int>> foo = (Func<Task<int>>){|IDE0390:async|} delegate
                    {
                        return 1;
                    };
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task<int>> foo = (Func<Task<int>>)delegate
                    {
                        return Task.FromResult(1);
                    };
                }
            }
            """);
 
    [Fact]
    public Task SimpleLambda_TaskOfT_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task<int>> foo = {|IDE0390:async|} x => 1;
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task<int>> foo = x => Task.FromResult(1);
                }
            }
            """);
 
    [Fact]
    public Task SimpleLambda_TaskOfT_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task<int>> foo = {|IDE0390:async|} x => {
                        return 1;
                    };
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task<int>> foo = x =>
                    {
                        return Task.FromResult(1);
                    };
                }
            }
            """);
 
    [Fact]
    public Task SimpleLambda_Task_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task> foo = {|IDE0390:async|} x => Console.WriteLine(1);
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task> foo = x => { Console.WriteLine(1); return Task.CompletedTask; };
                }
            }
            """);
 
    [Fact]
    public Task SimpleLambda_Task_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task> foo = {|IDE0390:async|} x =>
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return;
                        }
                    };
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<int, Task> foo = x =>
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return Task.CompletedTask;
                        }
 
                        return Task.CompletedTask;
                    };
                }
            }
            """);
 
    [Fact]
    public Task ParenthesizedLambda_TaskOfT_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task<int>> foo = {|IDE0390:async|} () => 1;
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task<int>> foo = () => Task.FromResult(1);
                }
            }
            """);
 
    [Fact]
    public Task ParenthesizedLambda_TaskOfT_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task<int>> foo = {|IDE0390:async|} () => {
                        return 1;
                    };
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task<int>> foo = () =>
                    {
                        return Task.FromResult(1);
                    };
                }
            }
            """);
 
    [Fact]
    public Task ParenthesizedLambda_Task_ExpressionBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task> foo = {|IDE0390:async|} () => Console.WriteLine(1);
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task> foo = () => { Console.WriteLine(1); return Task.CompletedTask; };
                }
            }
            """);
 
    [Fact]
    public Task ParenthesizedLambda_Task_BlockBody()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task> foo = {|IDE0390:async|} () =>
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return;
                        }
                    };
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                public void M1()
                {
                    Func<Task> foo = () =>
                    {
                        if (System.DateTime.Now.Ticks > 0)
                        {
                            return Task.CompletedTask;
                        }
 
                        return Task.CompletedTask;
                    };
                }
            }
            """);
 
    [Fact]
    public Task Method_Task_BlockBody_FullyQualified()
        => VerifyCS.VerifyCodeFixAsync(
            """
            class C
            {
                {|IDE0390:async|} System.Threading.Tasks.Task Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return;
                    }
                }
            }
            """,
            """
            class C
            {
                System.Threading.Tasks.Task Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return System.Threading.Tasks.Task.CompletedTask;
                    }
 
                    return System.Threading.Tasks.Task.CompletedTask;
                }
            }
            """);
 
    [Fact]
    public Task Method_TaskOfT_BlockBody_FullyQualified()
        => VerifyCS.VerifyCodeFixAsync(
            """
            class C
            {
                {|IDE0390:async|} System.Threading.Tasks.Task<int> Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return 1;
                    }
 
                    return 2;
                }
            }
            """,
            """
            class C
            {
                System.Threading.Tasks.Task<int> Goo()
                {
                    if (System.DateTime.Now.Ticks > 0)
                    {
                        return System.Threading.Tasks.Task.FromResult(1);
                    }
 
                    return System.Threading.Tasks.Task.FromResult(2);
                }
            }
            """);
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/65536")]
    public Task Method_TaskOfT_BlockBody_QualifyTaskFromResultType()
        => VerifyCS.VerifyCodeFixAsync("""
            using System.Threading.Tasks;
            using System.Collections.Generic;
 
            class C
            {
                public {|IDE0390:async|} Task<IReadOnlyCollection<int>> M()
                {
                    return new int[0];
                }
            }
            """, """
            using System.Threading.Tasks;
            using System.Collections.Generic;
            
            class C
            {
                public Task<IReadOnlyCollection<int>> M()
                {
                    return Task.FromResult<IReadOnlyCollection<int>>(new int[0]);
                }
            }
            """);
 
    [Fact]
    public async Task IAsyncEnumerable_Missing()
    {
        var source = """
            using System.Threading.Tasks;
            using System.Collections.Generic;
 
            class C
            {
                {|IDE0390:async|} IAsyncEnumerable<int> M()
                {
                    yield return 1;
                }
            }
            """ + CSharpTestBase.AsyncStreamsTypes;
 
        await new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = source,
            FixedCode = source,
        }.RunAsync();
    }
 
    [Fact]
    public async Task Method_AsyncVoid_Missing()
    {
        var source = """
            using System.Threading.Tasks;
 
            class C
            {
                {|IDE0390:async|} void M()
                {
                    System.Console.WriteLine(1);
                }
            }
            """;
 
        await new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = source,
            FixedCode = source,
        }.RunAsync();
    }
 
    [Fact]
    public async Task ParenthesizedLambda_AsyncVoid_Missing()
    {
        var source = """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                void M()
                {
                    Action a = {|IDE0390:async|} () => Console.WriteLine(1);
                }
            }
            """;
 
        await new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = source,
            FixedCode = source,
        }.RunAsync();
    }
 
    [Fact]
    public async Task SimpleLambda_AsyncVoid_Missing()
    {
        var source = """
            using System;
            using System.Threading.Tasks;
 
            class C
            {
                void M()
                {
                    Action<int> a = {|IDE0390:async|} x => Console.WriteLine(x);
                }
            }
            """;
 
        await new VerifyCS.Test
        {
            ReferenceAssemblies = ReferenceAssemblies.NetStandard.NetStandard21,
            TestCode = source,
            FixedCode = source,
        }.RunAsync();
    }
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/65380")]
    public Task TestCloseBraceTrivia()
        => VerifyCS.VerifyCodeFixAsync(
            """
            using System;
            using System.Threading.Tasks;
 
            public class Class1
            {
                public {|IDE0390:async|} Task Goo()
                {
                    //Hello 
                    Console.WriteLine("Goo");
                    //World
                }
            }
            """,
            """
            using System;
            using System.Threading.Tasks;
            
            public class Class1
            {
                public Task Goo()
                {
                    //Hello 
                    Console.WriteLine("Goo");
                    return Task.CompletedTask;
                    //World
                }
            }
            """);
}
File: src\Analyzers\CSharp\Tests\RemoveAsyncModifier\RemoveAsyncModifierTests.cs	Web Access
Project: src\src\Features\CSharpTest\Microsoft.CodeAnalysis.CSharp.Features.UnitTests.csproj (Microsoft.CodeAnalysis.CSharp.Features.UnitTests)