ExtractMethodCodeRefactoringProvider threw "System.InvalidOperationException : Failed to compare two elements in the array"

[davkean]

Was editing something in this code, I'm not sure what caused it:

using System;
using System.Collections.Generic;
using Microsoft.VisualStudio.Setup;
using WillowDepends.Lib;
using static System.Console;

namespace WillowDepends.Console
{
    class Program
    {
        static void Main(string[] args)
        {
            var manifest = Manifest.FromManifestFile(@"\\cpvsbuild\Drops\VS\d15.6\products\27420.00\VisualStudio.vsman");

            foreach (var workload in manifest.Workloads)
            {
                if (!Contains461(manifest, workload))
                {
                    PrintPackageDependencies(manifest, workload);
                }
            }
        }

        private static bool Contains461(Manifest manifest, IPackage workload)
        {
            var alreadySeenPackages = new List<string>();
            bool PringPackage(IPackage package, int v)
            {
                if (alreadySeenPackages.Contains(package.Id.ToLower()))
                {
                    return false;
                }

                alreadySeenPackages.Add(package.Id.ToLower());
                for (int i = 0; i < v; i++)
                {
                    if (package.Id == "Microsoft.Net.PackageGroup.4.6.1.Redist")
                        return true;
                }

                foreach (var dependency in package.Dependencies)
                {
                    if (PringPackage(manifest[dependency.Id], v + 2))
                        return true;
                }

                return false;
            }

            alreadySeenPackages.Add(workload.Id.ToLower());
            
            foreach (var dependency in workload.Dependencies)
            {
                if (PringPackage(manifest[dependency.Id], 4))
                    return true;
            }

            return false;

        }

        static void PrintPackageDependencies(Manifest manifest, IPackage workload)
        {
            var alreadySeenPackages = new List<string>();
            void PringPackage(IPackage package, int v)
            {
                if (alreadySeenPackages.Contains(package.Id.ToLower()))
                {
                    return;
                }

                alreadySeenPackages.Add(package.Id.ToLower());
                for (int i = 0; i < v; i++)
                {
                    Write(" ");
                }
                Write(package.Id);
                Write(Environment.NewLine);
                foreach (var dependency in package.Dependencies)
                {
                    PringPackage(manifest[dependency.Id], v + 2);
                }
            }

            alreadySeenPackages.Add(workload.Id.ToLower());
            WriteLine(workload.Id);
            //foreach (var dependency in workload.Dependencies)
            //{
            //    PringPackage(manifest[dependency.Id], 4);
            //}
        }
    }
}

Resulted in:

System.InvalidOperationException : Failed to compare two elements in the array. ---> System.InvalidOperationException : Shouldn't reach here
   at Roslyn.Utilities.Contract.FailWithReturn[T](String message)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.ParameterVariableSymbol.CompareTo(IMethodSymbol left,IMethodSymbol right)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.ParameterVariableSymbol.CompareTo(ParameterVariableSymbol other)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.ParameterVariableSymbol.CompareTo(VariableSymbol right)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.VariableSymbol.Compare(VariableSymbol left,VariableSymbol right,INamedTypeSymbol cancellationTokenType)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.VariableInfo.<>c__DisplayClass24_0.<SortVariables>b__0(VariableInfo v1,VariableInfo v2)
   at System.Array.FunctorComparer`1.Compare(T x,T y)
   at System.Collections.Generic.ArraySortHelper`1.InsertionSort(T[] keys,Int32 lo,Int32 hi,IComparer`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.IntroSort(T[] keys,Int32 lo,Int32 hi,Int32 depthLimit,IComparer`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.IntrospectiveSort(T[] keys,Int32 left,Int32 length,IComparer`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys,Int32 index,Int32 length,IComparer`1 comparer)
   --- End of inner exception stack trace ---
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys,Int32 index,Int32 length,IComparer`1 comparer)
   at System.Array.Sort[T](T[] array,Int32 index,Int32 length,IComparer`1 comparer)
   at System.Collections.Generic.List`1.Sort(Comparison`1 comparison)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.VariableInfo.SortVariables(Compilation compilation,List`1 list)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.GetMethodParameters(ICollection`1 variableInfo)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.GetSignatureInformation(DataFlowAnalysis dataFlowAnalysisData,IDictionary`2 variableInfoMap,Boolean isInExpressionOrHasReturnStatement)
   at async Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.AnalyzeAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.ExtractMethodAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.ExtractMethod.AbstractExtractMethodService`3.ExtractMethodAsync[TValidator,TExtractor,TResult](<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.GetCodeActionAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.ComputeRefactoringsAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.CodeRefactorings.CodeRefactoringService.GetRefactoringFromProviderAsync(<Unknown Parameters>)
   at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)

I do not know what the repro is.

[josefpihrt]

maybe a duplicate of #23175

[davkean]

@josefpihrt Yep, I agree, closing in lieu of it.