RR0021ChangeMethodReturnTypeToVoidTests.cs

// Copyright (c) Josef Pihrt and Contributors. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.Threading.Tasks;
using Roslynator.Testing.CSharp;
using Xunit;

namespace Roslynator.CSharp.Refactorings.Tests;

public class RR0021ChangeMethodReturnTypeToVoidTests : AbstractCSharpRefactoringVerifier
{
    public override string RefactoringId { get; } = RefactoringIdentifiers.ChangeMethodReturnTypeToVoid;

    public override CSharpTestOptions Options
    {
        get { return base.Options.AddAllowedCompilerDiagnosticId(CompilerDiagnosticIdentifiers.CS0161_NotAllCodePathsReturnValue); }
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task Test_Method()
    {
        await VerifyRefactoringAsync(@"
class C
{
    string M()
    {[||]
        M();
    }
}
", @"
class C
{
    void M()
    {
        M();
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task Test_Method_IEnumerableOfT()
    {
        await VerifyRefactoringAsync(@"
class C
{
    System.Collections.Generic.IEnumerable<string> M()
    {[||]
        M();
    }
}
", @"
class C
{
    void M()
    {
        M();
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task Test_LocalFunction()
    {
        await VerifyRefactoringAsync(@"
class C
{
    void M()
    {
        string LF()
        {[||]
            LF();
        }
    }
}
", @"
class C
{
    void M()
    {
        void LF()
        {
            LF();
        }
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_MethodWithReturn()
    {
        await VerifyNoRefactoringAsync(@"
class C
{
    string M()
    {[||]
        return M();
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_VoidMethod()
    {
        await VerifyNoRefactoringAsync(@"
class C
{
    void M()
    {[||]
        M();
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_Iterator()
    {
        await VerifyNoRefactoringAsync(@"
using System.Collections.Generic;

class C
{
    IEnumerable<string> M()
    {[||]
        yield return null;
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_Iterator_YieldBreak()
    {
        await VerifyNoRefactoringAsync(@"
using System.Collections.Generic;

class C
{
    IEnumerable<string> M()
    {[||]
        yield break;
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_ReturnsTask()
    {
        await VerifyNoRefactoringAsync(@"
using System.Threading.Tasks;

class C
{
    async Task M()
    {[||]
        string x = await Task.FromResult(default(string));
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_Throws()
    {
        await VerifyNoRefactoringAsync(@"
using System;

class C
{
    string M()
    {[||]
        throw new InvalidOperationException();
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_InterfaceImplementation()
    {
        await VerifyNoRefactoringAsync(@"
interface IFoo
{
    string M();
}

class C : IFoo
{
    public string M()
    {[||]
        M();
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }

    [Fact, Trait(Traits.Refactoring, RefactoringIdentifiers.ChangeMethodReturnTypeToVoid)]
    public async Task TestNoRefactoring_Override()
    {
        await VerifyNoRefactoringAsync(@"
class B
{
    public virtual string M() => null;
}

class C : B
{
    public override string M()
    {[||]
        object x = null;
    }
}
", equivalenceKey: EquivalenceKey.Create(RefactoringId));
    }
}