Using System.Void as a type argument in class constructor makes PSReadLine throw an exception #4324
Description
Prerequisites
- Write a descriptive title.
- Make sure you are able to repro it on the latest released version
- Search the existing issues, especially the pinned issues.
Exception report
### Environment
PSReadLine: 2.3.5+2cc85806c561a9395751a96a818e8ff1592d19f7
PowerShell: 7.4.6
OS: Microsoft Windows 10.0.19045
BufferWidth: 150
BufferHeight: 300
Last 54 Keys:
c l a s s Spacebar M y C l a s s Enter
{ Enter
Spacebar Spacebar h i d d e n Spacebar M u C l a Backspace Backspace Backspace Backspace y C l a s s ( [ V o i d ] $ V o i d ) {
### Exception
System.ArgumentException: The type 'System.Void' may not be used as a type argument.
at System.RuntimeType.SanityCheckGenericArguments(RuntimeType[] genericArguments, RuntimeType[] genericParameters)
at System.RuntimeType.MakeGenericType(Type[] instantiation)
at System.Management.Automation.Language.VariableAnalysis.FinishAnalysis(Boolean scriptCmdlet)
at System.Management.Automation.Language.VariableAnalysis.AnalyzeMemberFunction(FunctionMemberAst ast)
at System.Management.Automation.Language.SemanticChecks.VisitFunctionMember(FunctionMemberAst functionMemberAst)
at System.Management.Automation.Language.FunctionMemberAst.InternalVisit(AstVisitor visitor)
at System.Management.Automation.Language.TypeDefinitionAst.InternalVisit(AstVisitor visitor)
at System.Management.Automation.Language.NamedBlockAst.InternalVisit(AstVisitor visitor)
at System.Management.Automation.Language.ScriptBlockAst.InternalVisit(AstVisitor visitor)
at System.Management.Automation.Language.Parser.ParseTask(String fileName, String input, List`1 tokenList, Boolean recursed, ParseMode parseMode)
at System.Management.Automation.Language.Parser.Parse(String fileName, String input, List`1 tokenList, ParseError[]& errors, ParseMode parseMode)
at System.Management.Automation.Language.Parser.ParseInput(String input, String fileName, Token[]& tokens, ParseError[]& errors)Screenshot
Environment data
PS Version: 7.4.6
PS HostName: ConsoleHost
PSReadLine Version: 2.3.5
PSReadLine EditMode: Windows
OS: 10.0.19041.1 (WinBuild.160101.0800)
BufferWidth: 150
BufferHeight: 300Steps to reproduce
While defining a custom class from the command line, specifying [System.Void] as a constructor type argument causes PSReadLine to throw an exception.
Expected behavior
PowerShell to throw a System.ArgumentException and PSReadLine functionality to remain available in the current PS session.
Actual behavior
PSReadLine throws a System.ArgumentException. PowerShell is still running, but PSReadLine functionality is not until a new PS session is started.
Activity
daxian-dbw commentedon Jan 6, 2025
The exception is thrown by PowerShell when parsing the input script and it's a legit error to be thrown because it's invalid to use
System.Voidfor a parameter type, or variable type. It's only used to represent the absence of a return value for a method.