CSharpUseImplicitObjectCreationTests.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.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.UseImplicitObjectCreation;
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.UseImplicitObjectCreationTests;
 
using VerifyCS = CSharpCodeFixVerifier<
    CSharpUseImplicitObjectCreationDiagnosticAnalyzer,
    CSharpUseImplicitObjectCreationCodeFixProvider>;
 
[Trait(Traits.Feature, Traits.Features.CodeActionsUseImplicitObjectCreation)]
public class UseImplicitObjectCreationTests
{
    [Fact]
    public async Task TestMissingBeforeCSharp9()
    {
        var source = """
                class C
                {
                    C c = new C();
                }
                """;
        await new VerifyCS.Test
        {
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp8,
            TestCode = source,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestAfterCSharp9()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C c = new [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    C c = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithObjectInitializer()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C c = new [|C|]() { };
                }
                """,
            FixedCode = """
                class C
                {
                    C c = new() { };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithObjectInitializerWithoutArguments()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C c = new [|C|] { };
                }
                """,
            FixedCode = """
                class C
                {
                    C c = new() { };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithTriviaAfterNew()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C c = new /*x*/ [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    C c = new /*x*/ ();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithDifferentTypes()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    object c = new C();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithErrorTypes()
    {
        await new VerifyCS.Test
        {
            TestState = {
                Sources =
                {
                    """
                        class C
                        {
                            {|#0:E|} c = new {|#1:E|}();
                        }
                        """
                },
                ExpectedDiagnostics =
                {
                    // /0/Test0.cs(4,5): error CS0246: The type or namespace name 'E' could not be found (are you missing a using directive or an assembly reference?)
                    DiagnosticResult.CompilerError("CS0246").WithLocation(0).WithArguments("E"),
                    // /0/Test0.cs(4,15): error CS0246: The type or namespace name 'E' could not be found (are you missing a using directive or an assembly reference?)
                    DiagnosticResult.CompilerError("CS0246").WithLocation(1).WithArguments("E"),
                }
            },
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithDynamic()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    dynamic c = new C();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithArrayTypes()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    int[] c = new int[0];
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithTypeParameter()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C<T> where T : new()
                {
                    T t = new [|T|]();
                }
                """,
            FixedCode = """
                class C<T> where T : new()
                {
                    T t = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithLocalWhenUserDoesNotPreferVar()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    void M()
                    {
                        C c = new [|C|]();
                    }
                }
                """,
            FixedCode = """
                class C
                {
                    void M()
                    {
                        C c = new();
                    }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
            Options =
            {
                { CSharpCodeStyleOptions.VarWhenTypeIsApparent, CodeStyleOption2.FalseWithSuggestionEnforcement },
            }
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithLocalWhenUserDoesPreferVar()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    void M()
                    {
                        C c = new C();
                    }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
            Options =
            {
                { CSharpCodeStyleOptions.VarWhenTypeIsApparent, CodeStyleOption2.TrueWithSuggestionEnforcement },
            }
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithForVariable()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    void M()
                    {
                        for (C c = new [|C|]();;)
                        {
                        }
                    }
                }
                """,
            FixedCode = """
                class C
                {
                    void M()
                    {
                        for (C c = new();;)
                        {
                        }
                    }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithLocalFunctionExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    void M()
                    {
                        C Func() => new [|C|]();
                    }
                }
                """,
            FixedCode = """
                class C
                {
                    void M()
                    {
                        C Func() => new();
                    }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithMethodExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C Func() => new [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    C Func() => new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithConversionExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    public static implicit operator C(int i) => new [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    public static implicit operator C(int i) => new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithOperatorExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    public static C operator +(C c1, C c2) => new [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    public static C operator +(C c1, C c2) => new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithPropertyExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C P => new [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    C P => new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithPropertyAccessorExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C P { get => new [|C|](); }
                }
                """,
            FixedCode = """
                class C
                {
                    C P { get => new(); }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithPropertySetAccessorExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C P { set => new C(); }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithIndexerExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C this[int i] => new [|C|]();
                }
                """,
            FixedCode = """
                class C
                {
                    C this[int i] => new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestWithIndexerAccessorExpressionBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C this[int i] { get => new [|C|](); }
                }
                """,
            FixedCode = """
                class C
                {
                    C this[int i] { get => new(); }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotWithMethodBlockBody()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    C Func() { return new C(); }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotInNonApparentCode1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    void X() => Bar(new C());
                    void Bar(C c) { }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestNotInNonApparentCode2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                class C
                {
                    void X()
                    {
                        C c;
                        c = new C();
                    }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestQualifiedUnqualified1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
                class C
                {
                    List<int> list = new [|System.Collections.Generic.List<int>|]();
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                class C
                {
                    List<int> list = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestQualifiedUnqualified2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
                class C
                {
                    System.Collections.Generic.List<int> list = new [|List<int>|]();
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                class C
                {
                    System.Collections.Generic.List<int> list = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestAlias()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
                using X = System.Collections.Generic.List<int>;
                class C
                {
                    System.Collections.Generic.List<int> list = new [|X|]();
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                using X = System.Collections.Generic.List<int>;
                class C
                {
                    System.Collections.Generic.List<int> list = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact]
    public async Task TestFixAll1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System;
                class C
                {
                    public C() { }
                    public C(Action action) { }
 
                    C c1 = new [|C|](() =>
                    {
                        C c2 = new [|C|]();
                    });
                }
                """,
            FixedCode = """
                using System;
                class C
                {
                    public C() { }
                    public C(Action action) { }
 
                    C c1 = new(() =>
                    {
                        C c2 = new();
                    });
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/49291")]
    public async Task TestListOfTuplesWithLabels()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
                class C
                {
                    List<(int SomeName, int SomeOtherName, int YetAnotherName)> list = new [|List<(int SomeName, int SomeOtherName, int YetAnotherName)>|]();
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                class C
                {
                    List<(int SomeName, int SomeOtherName, int YetAnotherName)> list = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/49291")]
    public async Task TestListOfTuplesWithoutLabels()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
                class C
                {
                    List<(int SomeName, int SomeOtherName, int YetAnotherName)> list = new [|List<(int, int, int)>|]();
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                class C
                {
                    List<(int SomeName, int SomeOtherName, int YetAnotherName)> list = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/49291")]
    public async Task TestListOfTuplesWithoutLabelsAsLocal()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
                class C
                {
                    void M()
                    {
                        List<(int SomeName, int SomeOtherName, int YetAnotherName)> list = new [|List<(int, int, int)>|]();
                    }
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                class C
                {
                    void M()
                    {
                        List<(int SomeName, int SomeOtherName, int YetAnotherName)> list = new();
                    }
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57777")]
    public async Task TestMissingOnNullableStruct()
    {
        var source = """
                class C
                {
                    int? i = new int?();
                }
                """;
        await new VerifyCS.Test
        {
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
            TestCode = source,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57777")]
    public async Task TestOnNullableReferenceType()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                #nullable enable
                class C
                {
                    C? c = new [|C|]();
                }
                """,
            FixedCode = """
                #nullable enable
                class C
                {
                    C? c = new();
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestOnSingleDimensionalCollectionConstruction1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    IList<C> list = new List<C> { new [|C|]() };
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                
                class C
                {
                    IList<C> list = new List<C> { new() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestOnSingleDimensionalCollectionConstruction2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    IList<C> list = new List<C>() { new [|C|]() };
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                
                class C
                {
                    IList<C> list = new List<C>() { new() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestOnSingleDimensionalCollectionConstruction3()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    List<C> list = new [|List<C>|]() { new [|C|]() };
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                
                class C
                {
                    List<C> list = new() { new C() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestNotOnSingleDimensionalImplicitCollectionConstruction2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    List<C> list = new() { new C() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestNotOnMultiDimensionalImplicitCollectionConstruction2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    IDictionary<C, C> d = new Dictionary<C, C>() { { new C(), new C() } };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestOnSingleDimensionalArrayConstruction1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    C[] list = new C[] { new [|C|]() };
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                
                class C
                {
                    C[] list = new C[] { new() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestOnSingleDimensionalArrayConstruction2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    C[] list = { new [|C|]() };
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
                
                class C
                {
                    C[] list = { new() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestNotOnSingleDimensionalImplicitArrayConstruction2()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    C[] list = new[] { new C() };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestNotOnTwoDimensionalArrayConstruction1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    C[,] list = new C[,] { { new C(), new C() } };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
 
    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/57789")]
    public async Task TestOnInnerJaggedArray1()
    {
        await new VerifyCS.Test
        {
            TestCode = """
                using System.Collections.Generic;
 
                class C
                {
                    C[][] list = new C[][] { new C[] { new [|C|]() } };
                }
                """,
            FixedCode = """
                using System.Collections.Generic;
 
                class C
                {
                    C[][] list = new C[][] { new C[] { new() } };
                }
                """,
            LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
        }.RunAsync();
    }
}
File: src\Analyzers\CSharp\Tests\UseImplicitObjectCreation\CSharpUseImplicitObjectCreationTests.cs	Web Access
Project: src\src\Features\CSharpTest\Microsoft.CodeAnalysis.CSharp.Features.UnitTests.csproj (Microsoft.CodeAnalysis.CSharp.Features.UnitTests)