// 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;
using Microsoft.CodeAnalysis.CSharp.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.InitializeParameter;
using Microsoft.CodeAnalysis.CSharp.Shared.Extensions;
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.InitializeParameter
{
    using VerifyCS = CSharpCodeRefactoringVerifier<CSharpAddParameterCheckCodeRefactoringProvider>;
 
    [Trait(Traits.Feature, Traits.Features.CodeActionsInitializeParameter)]
    public class AddParameterCheckTests
    {
        [Fact]
        public async Task TestEmptyFile()
        {
            var code = @"[||]";
 
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestSimpleReferenceType_AlreadyNullChecked()
        {
            var testCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp11,
                TestCode = testCode,
                FixedCode = testCode
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestSimpleReferenceType()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestSimpleReferenceType_CSharp6()
        {
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp6,
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s == null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestNullable()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C([||]int? i)
                    {
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(int? i)
                    {
                        if (i is null)
                        {
                            throw new ArgumentNullException(nameof(i));
                        }
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/47030")]
        public async Task TestNotOnOutParameter()
        {
            var code = """
                class C
                {
                    public C([||]out string s)
                    {
                        s = "";
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestNotOnValueType()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]int i)
                    {
                    }
                }
                """;
 
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestNotOnInterfaceParameter()
        {
            var code = """
                using System;
 
                interface I
                {
                    void M([||]string s);
                }
                """;
 
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestNotOnNullableParameter()
        {
            var code = """
                #nullable enable
 
                using System;
 
                class C
                {
                    void M([||]string? s)
                    {
                    }
                }
                """;
 
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestNotOnAbstractParameter()
        {
            var code = """
                using System;
 
                abstract class C
                {
                    public abstract void M([||]string s);
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestNotOnExternParameter()
        {
            var code = """
                using System;
 
                class C
                {
                    extern void M([||]string s);
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Theory]
        [InlineData(LanguageVersion.CSharp11)]
        [InlineData(LanguageVersion.CSharp8)]
        public async Task TestNotOnPartialMethodDefinition1(LanguageVersion languageVersion)
        {
            var code = """
                using System;
 
                partial class C
                {
                    partial void M([||]string s);
 
                    partial void M(string s)
                    {
                    }
                }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = languageVersion,
                TestCode = code,
                FixedCode = code
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestNotOnExtendedPartialMethodDefinition1()
        {
            var code = """
                using System;
 
                partial class C
                {
                    public partial void M([||]string s);
 
                    public partial void M(string s)
                    {
                    }
                }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp9,
                TestCode = code,
                FixedCode = code
            }.RunAsync();
        }
 
        [Theory]
        [InlineData(LanguageVersion.CSharp11)]
        [InlineData(LanguageVersion.CSharp8)]
        public async Task TestNotOnPartialMethodDefinition2(LanguageVersion languageVersion)
        {
            var code = """
                using System;
 
                partial class C
                {
                    partial void M(string s)
                    {
                    }
 
                    partial void M([||]string s);
                }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = languageVersion,
                TestCode = code,
                FixedCode = code
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestNotOnExtendedPartialMethodDefinition2()
        {
            var code = """
                using System;
 
                partial class C
                {
                    public partial void M(string s)
                    {
                    }
 
                    public partial void M([||]string s);
                }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp9,
                TestCode = code,
                FixedCode = code
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestOnPartialMethodImplementation1()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                partial class C
                {
                    partial void M(string s);
 
                    partial void M([||]string s)
                    {
                    }
                }
                """,
                """
                using System;
 
                partial class C
                {
                    partial void M(string s);
 
                    partial void M(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestOnExtendedPartialMethodImplementation1()
        {
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp9,
                TestCode = """
                using System;
 
                partial class C
                {
                    public partial void M(string s);
 
                    public partial void M([||]string s)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                partial class C
                {
                    public partial void M(string s);
 
                    public partial void M(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestOnPartialMethodImplementation2()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                partial class C
                {
                    partial void M([||]string s)
                    {
                    }
 
                    partial void M(string s);
                }
                """,
                """
                using System;
 
                partial class C
                {
                    partial void M(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
 
                    partial void M(string s);
                }
                """);
        }
 
        [Fact]
        public async Task TestOnExtendedPartialMethodImplementation2()
        {
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp9,
                TestCode = """
                using System;
 
                partial class C
                {
                    public partial void M([||]string s)
                    {
                    }
 
                    public partial void M(string s);
                }
                """,
                FixedCode = """
                using System;
 
                partial class C
                {
                    public partial void M(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
 
                    public partial void M(string s);
                }
                """
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestUpdateExistingFieldAssignment()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    private string _s;
 
                    public C([||]string s)
                    {
                        _s = s;
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    private string _s;
 
                    public C(string s)
                    {
                        _s = s ?? throw new ArgumentNullException(nameof(s));
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestMultiNullableParameters()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string a, string b, string c)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string a, string b, string c)
    {{
        if (string.IsNullOrEmpty(a))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(a)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(a));
        }}
 
        if (string.IsNullOrEmpty(b))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(b)}").Replace("""
                                            "
                                            """, """
                                            \"
                                            """)}"", nameof(b));
        }}
 
        if (string.IsNullOrEmpty(c))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(c)}").Replace("""
                                                     "
                                                     """, """
                                                     \"
                                                     """)}"", nameof(c));
        }}
    }}
}}",
                CodeActionIndex = 3,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestMultiNullableParametersSomeNullableReferenceTypes()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                #nullable enable
 
                using System;
 
                class C
                {
                    public C([||]string a, string b, string? c)
                    {
                    }
                }
                """,
                FixedCode = @$"#nullable enable
 
using System;
 
class C
{{
    public C(string a, string b, string? c)
    {{
        if (string.IsNullOrEmpty(a))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(a)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(a));
        }}
 
        if (string.IsNullOrEmpty(b))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(b)}").Replace("""
                                            "
                                            """, """
                                            \"
                                            """)}"", nameof(b));
        }}
    }}
}}",
                CodeActionIndex = 3,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestCursorNotOnParameters()
        {
            var code = """
                using System;
 
                class C
                {
                    public C(string a[|,|] string b, string c)
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMultiNullableWithCursorOnNonNullable()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C(string a, [||]bool b, string c)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string a, bool b, string c)
    {{
        if (string.IsNullOrEmpty(a))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(a)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(a));
        }}
 
        if (string.IsNullOrEmpty(c))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(c)}").Replace("""
                                            "
                                            """, """
                                            \"
                                            """)}"", nameof(c));
        }}
    }}
}}",
                CodeActionIndex = 0,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestMultiNullableNonNullable()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string a, bool b, string c)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string a, bool b, string c)
    {{
        if (string.IsNullOrEmpty(a))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(a)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(a));
        }}
 
        if (string.IsNullOrEmpty(c))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(c)}").Replace("""
                                            "
                                            """, """
                                            \"
                                            """)}"", nameof(c));
        }}
    }}
}}",
                CodeActionIndex = 3,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestMultiNullableStringsAndObjects()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string a, object b, string c)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string a, object b, string c)
    {{
        if (string.IsNullOrEmpty(a))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(a)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(a));
        }}
 
        if (b is null)
        {{
            throw new ArgumentNullException(nameof(b));
        }}
 
        if (string.IsNullOrEmpty(c))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(c)}").Replace("""
                                            "
                                            """, """
                                            \"
                                            """)}"", nameof(c));
        }}
    }}
}}",
                CodeActionIndex = 3,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestMultiNullableObjects()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]object a, object b, object c)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object a, object b, object c)
                    {
                        if (a is null)
                        {
                            throw new ArgumentNullException(nameof(a));
                        }
 
                        if (b is null)
                        {
                            throw new ArgumentNullException(nameof(b));
                        }
 
                        if (c is null)
                        {
                            throw new ArgumentNullException(nameof(c));
                        }
                    }
                }
                """,
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestMultiNullableStructs()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]int ? a, bool ? b, double ? c)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(int ? a, bool ? b, double ? c)
                    {
                        if (a is null)
                        {
                            throw new ArgumentNullException(nameof(a));
                        }
 
                        if (b is null)
                        {
                            throw new ArgumentNullException(nameof(b));
                        }
 
                        if (c is null)
                        {
                            throw new ArgumentNullException(nameof(c));
                        }
                    }
                }
                """,
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestUpdateExistingPropertyAssignment()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    private string S;
 
                    public C([||]string s)
                    {
                        S = s;
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    private string S;
 
                    public C(string s)
                    {
                        S = s ?? throw new ArgumentNullException(nameof(s));
                    }
                }
                """);
        }
 
        [Fact]
        public async Task DoNotUseThrowExpressionBeforeCSharp7()
        {
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp6,
                TestCode = """
                using System;
 
                class C
                {
                    private string S;
 
                    public C([||]string s)
                    {
                        S = s;
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    private string S;
 
                    public C(string s)
                    {
                        if (s == null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
 
                        S = s;
                    }
                }
                """
            }.RunAsync();
        }
 
        [Fact]
        public async Task RespectUseThrowExpressionOption()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    private string S;
 
                    public C([||]string s)
                    {
                        S = s;
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    private string S;
 
                    public C(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
 
                        S = s;
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false, NotificationOption2.Silent }
                }
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestUpdateExpressionBody1()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    private string S;
 
                    public C([||]string s)
                        => S = s;
                }
                """,
                """
                using System;
 
                class C
                {
                    private string S;
 
                    public C(string s)
                        => S = s ?? throw new ArgumentNullException(nameof(s));
                }
                """);
        }
 
        [Fact]
        public async Task TestUpdateExpressionBody2()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C([||]string s)
                        => Init();
 
                    private void Init()
                    {
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
 
                        Init();
                    }
 
                    private void Init()
                    {
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestUpdateExpressionBody3()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                        => Init();
 
                    private void Init()
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
 
                        Init();
                    }
 
                    private void Init()
                    {
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferExpressionBodiedConstructors, CSharpCodeStyleOptions.WhenPossibleWithSuggestionEnforcement }
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestUpdateLocalFunctionExpressionBody_NonVoid()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        int F([||]string s) => Init();
                    }
 
                    private int Init() => 1;
                }
                """,
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        int F(string s)
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            return Init();
                        }
                    }
 
                    private int Init() => 1;
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestUpdateLocalFunctionExpressionBody_Void()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        void F([||]string s) => Init();
                    }
 
                    private int Init() => 1;
                }
                """,
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        void F(string s)
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            Init();
                        }
                    }
 
                    private int Init() => 1;
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestUpdateLambdaExpressionBody_NonVoid()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        Func<string, int> f = [||]s => GetValue();
 
                        int GetValue() => 0;
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        Func<string, int> f = s =>
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            return GetValue();
                        };
 
                        int GetValue() => 0;
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestUpdateLambdaExpressionBody_Void()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        Action<string> f = [||]s => NoValue();
 
                        void NoValue() { }
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    void M()
                    {
                        Action<string> f = s =>
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            NoValue();
                        };
 
                        void NoValue() { }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestInsertAfterExistingNullCheck1()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C(string a, [||]string s)
                    {
                        if (a == null)
                        {
                        }
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(string a, string s)
                    {
                        if (a == null)
                        {
                        }
 
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestInsertBeforeExistingNullCheck1()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C(string [||]a, string s)
                    {
                        if (s == null)
                        {
                        }
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(string a, string s)
                    {
                        if (a is null)
                        {
                            throw new ArgumentNullException(nameof(a));
                        }
 
                        if (s == null)
                        {
                        }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestMissingWithExistingNullCheck1()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                        if (s == null)
                        {
                            throw new ArgumentNullException();
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMissingWithExistingNullCheck2()
        {
            var code = """
                using System;
 
                class C
                {
                    private string _s;
 
                    public C([||]string s)
                    {
                        _s = s ?? throw new ArgumentNullException();
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMissingWithExistingNullCheck3()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                        if (string.IsNullOrEmpty(s))
                        {
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMissingWithExistingNullCheck4()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                        if (string.IsNullOrWhiteSpace(s))
                        {
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMissingWithExistingNullCheck5()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                        if (null == s)
                        {
                            throw new ArgumentNullException();
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMissingWithExistingNullCheck6()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException();
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestMissingWithExistingNullCheckInLocalFunction()
        {
            var code = """
                using System;
 
                class C
                {
                    public C()
                    {
                        void F([||]string s)
                        {
                            if (s == null)
                            {
                                throw new ArgumentNullException();
                            }
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestMissingWithExistingNullCheckInLambda()
        {
            var code = """
                using System;
 
                class C
                {
                    public C()
                    {
                        Action<string> f = ([||]string s) => { if (s == null) { throw new ArgumentNullException(nameof(s)); } };
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestMissingWithoutParameterName()
        {
            var code = """
                using System;
 
                class C
                {
                    public C([||]string{|CS1001:)|}
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestInMethod()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    void F([||]string s)
                    {
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    void F(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestInOperator()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public static C operator +(C c1, [||]string s)
                    {
                        return null;
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public static C operator +(C c1, [||]string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
 
                        return null;
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnSimpleLambdaParameter()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = [||]s => { return 0; };
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = s =>
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            return 0;
                        };
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnSimpleLambdaParameter_EmptyBlock()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Action<string> f = [||]s => { };
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Action<string> f = s =>
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
                        };
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnParenthesizedLambdaParameter()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = ([||]string s) => { return 0; };
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = (string s) =>
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            return 0;
                        };
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnDiscardLambdaParameter1()
        {
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp11,
                TestCode = """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = ([||]_) => { return 0; };
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = (_) =>
                        {
                            if (_ is null)
                            {
                                throw new ArgumentNullException(nameof(_));
                            }
 
                            return 0;
                        };
                    }
                }
                """
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnDiscardLambdaParameter2()
        {
            var testCode = """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, string, int> f = ([||]_, _) => { return 0; };
                    }
                }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.CSharp11,
                TestCode = testCode,
                FixedCode = testCode
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnAnonymousMethodParameter()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = delegate ([||]string s) { return 0; };
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        Func<string, int> f = delegate (string s)
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
 
                            return 0;
                        };
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/20983")]
        public async Task TestOnLocalFunctionParameter()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        void F([||]string s)
                        {
                        }
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C()
                    {
                        void F(string s)
                        {
                            if (s is null)
                            {
                                throw new ArgumentNullException(nameof(s));
                            }
                        }
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotOnIndexerParameter()
        {
            var code = """
                class C
                {
                    int this[[||]string s]
                    {
                        get
                        {
                            return 0;
                        }
                    }
                }
                """;
 
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        [WorkItem("https://github.com/dotnet/roslyn/issues/63307")]
        public async Task TestNotOnIndexerParameterInRecordWithParameter()
        {
            var code = """
                record R(string S)
                {
                    int this[[||]string s]
                    {
                        get
                        {
                            return 0;
                        }
                    }
                }
                """;
            await new VerifyCS.Test
            {
                TestCode = code,
                FixedCode = code,
                LanguageVersion = LanguageVersion.CSharp11,
                ReferenceAssemblies = ReferenceAssemblies.Net.Net50,
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestNotOnIndexerParameters()
        {
            var code = """
                class C
                {
                    int this[[|object a|], object b, object c]
                    {
                        get
                        {
                            return 0;
                        }
                    }
                }
                """;
 
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact]
        public async Task TestSpecialStringCheck1()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                FixedCode = $@"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
        }}
    }}
}}",
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestSpecialStringCheck2()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                FixedCode = $@"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrWhiteSpace(s))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_whitespace, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
        }}
    }}
}}",
                CodeActionIndex = 2,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrWhiteSpace_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/51338")]
        [UseCulture("de-DE", "de-DE")]
        public async Task TestSpecialStringCheck3()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                FixedCode = $@"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
        }}
    }}
}}",
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/19173")]
        public async Task TestMissingOnUnboundTypeWithExistingNullCheck()
        {
            var code = """
                class C
                {
                    public C(string [||]s)
                    {
                        if (s == null)
                        {
                            throw new System.Exception();
                        }
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/19174")]
        public async Task TestRespectPredefinedTypePreferences()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class Program
                {
                    static void Main([||]String bar)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class Program
{{
    static void Main(String bar)
    {{
        if (String.IsNullOrEmpty(bar))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(bar)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(bar));
        }}
    }}
}}",
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check),
                Options =
                {
                    { CodeStyleOptions2.PreferIntrinsicPredefinedTypeKeywordInMemberAccess, CodeStyleOption2.FalseWithSuggestionEnforcement }
                }
            }.RunAsync();
        }
 
        [Theory, WorkItem("https://github.com/dotnet/roslyn/issues/19172")]
        [InlineData((int)PreferBracesPreference.None)]
        [InlineData((int)PreferBracesPreference.WhenMultiline)]
        public async Task TestPreferNoBlock(int preferBraces)
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s is null) throw new ArgumentNullException(nameof(s));
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferBraces, new CodeStyleOption2<PreferBracesPreference>((PreferBracesPreference)preferBraces, NotificationOption2.Silent) },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/19956")]
        public async Task TestNoBlock()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C(string s[||])
                }
                """,
                ExpectedDiagnostics = {
                    // /0/Test0.cs(6,12): error CS0501: 'C.C(string)' must declare a body because it is not marked abstract, extern, or partial
                    DiagnosticResult.CompilerError("CS0501").WithLocation(5, 12).WithArguments("C.C(string)"),
                    // /0/Test0.cs(6,23): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithLocation(5, 23),
                },
                FixedState =
                {
                    Sources = { """
                        using System;
 
                        class C
                        {
                            public C(string s)
                            {
                                if (s is null)
                                {
                                    throw new ArgumentNullException(nameof(s));
                                }
                            }
                        }
                        """ },
                    InheritanceMode = StateInheritanceMode.Explicit
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/21501")]
        public async Task TestInArrowExpression1()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
                using System.Linq;
 
                class C
                {
                    public int Foo(int[] array[||]) =>
                        array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count();
                }
                """,
                """
                using System;
                using System.Linq;
 
                class C
                {
                    public int Foo(int[] array)
                    {
                        if (array is null)
                        {
                            throw new ArgumentNullException(nameof(array));
                        }
 
                        return array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count();
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/21501")]
        public async Task TestInArrowExpression2()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
                using System.Linq;
 
                class C
                {
                    public int Foo(int[] array[||]) /* Bar */ => /* Bar */
                        array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count(); /* Bar */
                }
                """,
                """
                using System;
                using System.Linq;
 
                class C
                {
                    public int Foo(int[] array) /* Bar */
                    {
                        if (array is null)
                        {
                            throw new ArgumentNullException(nameof(array));
                        }
                        /* Bar */
                        return array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count(); /* Bar */
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/21501")]
        public async Task TestMissingInArrowExpression1()
        {
            var code = """
                using System;
                using System.Linq;
 
                class C
                {
                    public void Foo(string bar[||]) =>
                #if DEBUG
                        Console.WriteLine("debug" + bar);
                #else
                        Console.WriteLine("release" + bar);
                #endif
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/21501")]
        public async Task TestMissingInArrowExpression2()
        {
            var code = """
                using System;
                using System.Linq;
 
                class C
                {
                    public int Foo(int[] array[||]) =>
                #if DEBUG
                        array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count();
                #else
                        array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count();
                #endif
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/21501")]
        public async Task TestInArrowExpression3()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
                using System.Linq;
 
                class C
                {
                    public void Foo(int[] array[||]) =>
                        array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count();
                }
                """,
                """
                using System;
                using System.Linq;
 
                class C
                {
                    public void Foo(int[] array)
                    {
                        if (array is null)
                        {
                            throw new ArgumentNullException(nameof(array));
                        }
 
                        array.Where(x => x > 3)
                            .OrderBy(x => x)
                            .Count();
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/29190")]
        public async Task TestSimpleReferenceTypeWithParameterNameSelected1()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                using System;
 
                class C
                {
                    public C(string [|s|])
                    {
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/29333")]
        public async Task TestLambdaWithIncorrectNumberOfParameters()
        {
            var code = """
                using System;
 
                class C
                {
                    void M(Action<int, int> a)
                    {
                        M((x[||]
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code,
                new[]
                {
                    // /0/Test0.cs(7,12): error CS0103: The name 'x' does not exist in the current context
                    DiagnosticResult.CompilerError("CS0103").WithSpan(7, 12, 7, 13).WithArguments("x"),
                    // /0/Test0.cs(7,13): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(7, 13, 7, 13),
                    // /0/Test0.cs(7,13): error CS1026: ) expected
                    DiagnosticResult.CompilerError("CS1026").WithSpan(7, 13, 7, 13),
                    // /0/Test0.cs(7,13): error CS1026: ) expected
                    DiagnosticResult.CompilerError("CS1026").WithSpan(7, 13, 7, 13),
                }, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/41824")]
        public async Task TestMissingInArgList()
        {
            var code = """
                class C
                {
                    private static void M()
                    {
                        M2(__arglist(1, 2, 3, 5, 6));
                    }
 
                    public static void M2([||]__arglist)
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(code, code);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52383")]
        public async Task TestImportSystem()
        {
            await VerifyCS.VerifyRefactoringAsync(
                """
                class C
                {
                    public C([||]string s)
                    {
                    }
                }
                """,
                """
                using System;
 
                class C
                {
                    public C(string s)
                    {
                        if (s is null)
                        {
                            throw new ArgumentNullException(nameof(s));
                        }
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_BracesNone_SameLineFalse()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$object o)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object o)
                    {
                        if (o is null)
                            throw new ArgumentNullException(nameof(o));
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.None },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, false },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_BracesWhenMultiline_SameLineFalse()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$object o)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object o)
                    {
                        if (o is null)
                            throw new ArgumentNullException(nameof(o));
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.WhenMultiline },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, false },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_BracesAlways_SameLineFalse()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$object o)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object o)
                    {
                        if (o is null)
                        {
                            throw new ArgumentNullException(nameof(o));
                        }
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.Always },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, false },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_BracesNone_SameLineTrue()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$object o)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object o)
                    {
                        if (o is null) throw new ArgumentNullException(nameof(o));
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.None },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_BracesWhenMultiline_SameLineTrue()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$object o)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object o)
                    {
                        if (o is null) throw new ArgumentNullException(nameof(o));
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.WhenMultiline },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_BracesAlways_SameLineTrue()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$object o)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object o)
                    {
                        if (o is null)
                        {
                            throw new ArgumentNullException(nameof(o));
                        }
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.Always },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                }
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_StringIsNullOrEmpty_BracesNone_SameLineFalse()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$string s)
                    {
                    }
                }
                """,
                FixedCode = $@"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s))
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
    }}
}}",
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.None },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, false },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_StringIsNullOrEmpty_BracesWhenMultiline_SameLineFalse()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$string s)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s))
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
    }}
}}",
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.WhenMultiline},
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, false },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_StringIsNullOrEmpty_BracesAlways_SameLineFalse()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$string s)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
        }}
    }}
}}",
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.Always },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, false },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_StringIsNullOrEmpty_BracesNone_SameLineTrue()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$string s)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s)) throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
    }}
}}",
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.None },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_StringIsNullOrEmpty_BracesWhenMultiline_SameLineTrue()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$string s)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s)) throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
    }}
}}",
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.WhenMultiline },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_StringIsNullOrEmpty_BracesAlways_SameLineTrue()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C($$string s)
                    {
                    }
                }
                """,
                FixedCode = @$"using System;
 
class C
{{
    public C(string s)
    {{
        if (string.IsNullOrEmpty(s))
        {{
            throw new ArgumentException($""{string.Format(FeaturesResources._0_cannot_be_null_or_empty, "{nameof(s)}").Replace("""
                                   "
                                   """, """
                                   \"
                                   """)}"", nameof(s));
        }}
    }}
}}",
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.Always },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_string_IsNullOrEmpty_check)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/52385")]
        public async Task SingleLineStatement_NullCheck_AllParameters()
        {
            await new VerifyCS.Test
            {
                TestCode = """
                using System;
 
                class C
                {
                    public C([||]object a, object b, object c)
                    {
                    }
                }
                """,
                FixedCode = """
                using System;
 
                class C
                {
                    public C(object a, object b, object c)
                    {
                        if (a is null) throw new ArgumentNullException(nameof(a));
                        if (b is null) throw new ArgumentNullException(nameof(b));
                        if (c is null) throw new ArgumentNullException(nameof(c));
                    }
                }
                """,
                Options =
                {
                    { CSharpCodeStyleOptions.PreferThrowExpression, false },
                    { CSharpCodeStyleOptions.PreferBraces, PreferBracesPreference.None },
                    { CSharpCodeStyleOptions.AllowEmbeddedStatementsOnSameLine, true },
                },
                CodeActionIndex = 1,
                CodeActionEquivalenceKey = nameof(FeaturesResources.Add_null_checks_for_all_parameters)
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/58811")]
        public async Task TestMissingParameter1()
        {
            var source = """
                using System;
 
                class C
                {
                    public C(string s,[||]{|CS1031:{|CS1001:)|}|}
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(source, source);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/58811")]
        public async Task TestMissingParameter2()
        {
            var source = """
                using System;
 
                class C
                {
                    public C(string s,[||] {|CS1031:{|CS1001:)|}|}
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(source, source);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/58811")]
        public async Task TestMissingParameter3()
        {
            var source = """
                using System;
 
                class C
                {
                    public C(string s, [||]{|CS1031:{|CS1001:)|}|}
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(source, source);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/58811")]
        public async Task TestMissingParameter4()
        {
            var source = """
                using System;
 
                class C
                {
                    public C(string s, [||] {|CS1031:{|CS1001:)|}|}
                    {
                    }
                }
                """;
            await VerifyCS.VerifyRefactoringAsync(source, source);
        }
 
        [Theory]
        [WorkItem("https://github.com/dotnet/roslyn/issues/58779")]
        [InlineData(LanguageVersion.CSharp10)]
        [InlineData(LanguageVersion.CSharp11)]
        public async Task TestNotInRecord(LanguageVersion version)
        {
            var code = """
                record C([||]string s) { public string s; }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = version,
                TestCode = code,
                FixedCode = code,
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestNotInClass()
        {
            var code = """
                class C([||]string s) { public string s; }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.Preview,
                TestCode = code,
                FixedCode = code,
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestNotInStruct()
        {
            var code = """
                struct C([||]string s) { public string s; }
                """;
            await new VerifyCS.Test
            {
                LanguageVersion = LanguageVersion.Preview,
                TestCode = code,
                FixedCode = code,
            }.RunAsync();
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/38093")]
        public async Task TestReadBeforeAssignment()
        {
            await VerifyCS.VerifyRefactoringAsync("""
                using System;
                using System.IO;
 
                class Program
                {
                    public Program([||]Stream output)
                    {
                        if (!output.CanWrite) throw new ArgumentException();
                        OutStream = output;
                    }
 
                    public Stream OutStream { get; }
                }
                """, """
                using System;
                using System.IO;
 
                class Program
                {
                    public Program([||]Stream output)
                    {
                        if (output is null)
                        {
                            throw new ArgumentNullException(nameof(output));
                        }
 
                        if (!output.CanWrite) throw new ArgumentException();
                        OutStream = output;
                    }
 
                    public Stream OutStream { get; }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/41140")]
        public async Task TestAfterComma1()
        {
            await VerifyCS.VerifyRefactoringAsync("""
                using System;
 
                class C
                {
                    // should generate for 'b'
                    void M(string a,$$ string b, string c)
                    {
 
                    }
                }
                """, """
                using System;
 
                class C
                {
                    // should generate for 'b'
                    void M(string a, string b, string c)
                    {
                        if (b is null)
                        {
                            throw new ArgumentNullException(nameof(b));
                        }
                    }
                }
                """);
        }
 
        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/41140")]
        public async Task TestAfterComma2()
        {
            await VerifyCS.VerifyRefactoringAsync("""
                using System;
 
                class C
                {
                    // should generate for 'a'
                    void M(string a,$$
                        string b, string c)
                    {
 
                    }
                }
                """, """
                using System;
 
                class C
                {
                    // should generate for 'a'
                    void M(string a,
                        string b, string c)
                    {
                        if (a is null)
                        {
                            throw new ArgumentNullException(nameof(a));
                        }
                    }
                }
                """);
        }
    }
}