RCS1124InlineLocalVariableTests.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 Microsoft.CodeAnalysis;
using Roslynator.CSharp.CodeFixes;
using Roslynator.Testing.CSharp;
using Xunit;

namespace Roslynator.CSharp.Analysis.Tests;

public class RCS1124InlineLocalVariableTests : AbstractCSharpDiagnosticVerifier<InlineLocalVariableAnalyzer, LocalDeclarationStatementCodeFixProvider>
{
    public override DiagnosticDescriptor Descriptor { get; } = DiagnosticRules.InlineLocalVariable;

    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.InlineLocalVariable)]
    public async Task Test_LocalDeclaration()
    {
        await VerifyDiagnosticAndFixAsync(@"
class C
{
    void M()
    {
        // a
        [|int x = 1 // b
            + 1;|]
        int y = x;
    }
}
", @"
class C
{
    void M()
    {
        // a
        int y = 1 // b
            + 1;
    }
}
");
    }

    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.InlineLocalVariable)]
    public async Task Test_YieldReturn()
    {
        await VerifyDiagnosticAndFixAsync(@"
using System.Collections.Generic;

class C
{
    IEnumerable<string> M()
    {
        [|var s = """";|]
        yield return s;
    }
}
", @"
using System.Collections.Generic;

class C
{
    IEnumerable<string> M()
    {
        yield return """";
    }
}
");
    }

    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.InlineLocalVariable)]
    public async Task Test_VarType()
    {
        await VerifyDiagnosticAndFixAsync(@"
#nullable enable

class C
{
    public string P { get; set; } = null!;

    void M()
    {
        var c = new C();

        [|var p = c.P;|]
        var s = p;
    }
}
", @"
#nullable enable

class C
{
    public string P { get; set; } = null!;

    void M()
    {
        var c = new C();

        var s = c.P;
    }
}
");
    }

    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.InlineLocalVariable)]
    public async Task TestNoDiagnostic_YieldReturnIsNotLastStatement()
    {
        await VerifyNoDiagnosticAsync(@"
using System.Collections.Generic;

class C
{
    IEnumerable<string> M()
    {
        var s = """";
        yield return s;
        s = null;
    }
}
");
    }

    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.InlineLocalVariable)]
    public async Task TestNoDiagnostic_ForEachWithAwait()
    {
        await VerifyNoDiagnosticAsync(@"
using System.Collections.Generic;
using System.Threading.Tasks;

class C
{
    async Task<IEnumerable<object>> GetAsync()
    {
        var items = await GetAsync();

        foreach (var item in items)
        {
        }

        return null;
    }
}
");
    }

    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.InlineLocalVariable)]
    public async Task TestNoDiagnostic_SwitchWithAwait()
    {
        await VerifyNoDiagnosticAsync(@"
using System.Threading.Tasks;

class C
{
    async Task<string> GetAsync()
    {
        var x = await GetAsync();

        switch (x)
        {
            case """":
                break;
        }

        return null;
    }
}
");
    }
}