Error message for invalid csharp_using_directive_placement is not clear

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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[severity:It's more difficult to complete my work]
Hi, when I run a CodeAnalysis on my . Net5 solution I see 72 warnings in the Error List (I think one for every file). All the warnings are AD0001:

Severity	Code	Description	Project	File	Line	Suppression State
Warning	AD0001	Analyzer 'Microsoft.CodeAnalysis.CSharp.MisplacedUsingDirectives.MisplacedUsingDirectivesDiagnosticAnalyzer' threw an exception of type 'System.NotSupportedException' with message 'Specified method is not supported.'.
Exception occurred with following context:
Compilation: Translator.Core
SyntaxTree: C:\Users\wvl\source\repos\KasparInternal.Tools.FlutterTranslationHelper\Translator.Core\TypeBuilder\EntryTypeBuilder.LanguagePropertyBuilder.cs
SyntaxNode: using System; using System.Linq ... [CompilationUnitSyntax]@[20..6103) (2,0)-(139,0)

System.NotSupportedException: Specified method is not supported.
   at Microsoft.CodeAnalysis.CSharp.CodeStyle.CSharpCodeStyleOptions.ParseUsingDirectivesPlacement(String optionString, CodeStyleOption2`1 default)
   at Microsoft.CodeAnalysis.CSharp.CodeStyle.CSharpCodeStyleOptions.<>c.<.cctor>b__46_9(String s)
   at Microsoft.CodeAnalysis.Options.EditorConfigStorageLocation`1.TryGetOption(String value, Type type, T& result)
   at Microsoft.CodeAnalysis.AnalyzerConfigOptionsExtensions.TryGetEditorConfigOption[T](AnalyzerConfigOptions analyzerConfigOptions, IOption option, Boolean useDefaultIfMissing, T& value)
   at Microsoft.CodeAnalysis.AnalyzerConfigOptionsExtensions.TryGetEditorConfigOption[T](AnalyzerConfigOptions analyzerConfigOptions, IOption option, T& value)
   at Microsoft.CodeAnalysis.Diagnostics.AnalyzerHelper. <GetOptionAsync>d__24`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at Microsoft.CodeAnalysis.Diagnostics.AnalyzerHelper.GetOption[T](AnalyzerOptions analyzerOptions, ILanguageSpecificOption`1 option, SyntaxTree syntaxTree, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.CSharp.MisplacedUsingDirectives.MisplacedUsingDirectivesDiagnosticAnalyzer.AnalyzeCompilationUnitNode(SyntaxNodeAnalysisContext context)
   at Microsoft.CodeAnalysis.Diagnostics.AnalyzerExecutor.<>c__62`1. <ExecuteSyntaxNodeAction>b__62_0(ValueTuple`2 data)
   at Microsoft.CodeAnalysis.Diagnostics.AnalyzerExecutor.ExecuteAndCatchIfThrows_NoLock[TArg](DiagnosticAnalyzer analyzer, Action`1 analyze, TArg argument, Nullable`1 info)
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Suppress the following diagnostics to disable this analyzer: IDE0065	Translator.Core		1	Active

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Original Comments

(no comments)

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Original Solutions

(no solutions)

[CyrusNajmabadi]

You have an editorconfig value for csharp_using_directive_placement that is not inside_namespace or outside_namespace.

[CyrusNajmabadi]

@sharwell @jinujoseph do we have a tracking bug about making these errors easier to diagnose? I would like to dupe this against that. It's def a probem that we just throw new NotSupportedException() without any sort of clear message to the user as to what the issue is.

[jinujoseph]

@JoeRobich thoughts ?

[JoeRobich]

We should remove throwing NotSupported when parsing the users editorconfig value string. Other parsing methods return the @default value when the string contains an unexpected value.

[sharwell]

@CyrusNajmabadi We have #19055 and #37347

[CyrusNajmabadi]

Closing out as covered by other analyzers.

[sharwell]

From #67299:

In the above case, the user has the following in their .editorconfig file:

# usings outside namespace
csharp_using_directive_placement = true

This is producing an exception in the following parsing code:

roslyn/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/CSharp/CodeStyle/CSharpCodeStyleOptions_Parsing.cs

Lines 55 to 60 in f994677

	return value switch
	{
	"inside_namespace" => new CodeStyleOption2<AddImportPlacement>(AddImportPlacement.InsideNamespace, notification),
	"outside_namespace" => new CodeStyleOption2<AddImportPlacement>(AddImportPlacement.OutsideNamespace, notification),
	_ => throw new NotSupportedException(),
	};

The parsing code should be updated to provide a more detailed (actionable) error message for users.