AvoidReservedCharInCmdlet throws System.NullReferenceException sometimes due to CommandInfo.ResolveParameter issue

I report this error although I cannot reproduce the bug, moreover the analyzed code is private 😕

The exception is random during a build via PSake. I already had this error with the previous version 1.8. The exception is most often raised when I open a powershell session and then execute my build script. When, after the triggering of the error, I relaunch my error script, I no longer have an error

I have not yet had time to run only the PSSA command line.

Actual behavior

[STA] E:\Projets\xxxx> $error[0]|select *


PSMessageDetails      :
Exception             : System.NullReferenceException: Object reference not set to an instance of an object.
                           at System.Management.Automation.CommandInfo.ResolveParameter(String name)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.Helper.GetExportedFunction(Ast ast)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules.AvoidReservedCharInCmdlet.<AnalyzeScript>d__0.MoveNext()
                           at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
                           at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.ScriptAnalyzer.<>c__DisplayClass83_1.<Analyze
                        SyntaxTree>b__2()
TargetObject          : E:\RELEASES\xxx\yyyy\Modules\Log4Posh\Log4Posh.psm1
CategoryInfo          : InvalidOperation: (E:\RELEASES\xxx…\Log4Posh.psm1:String) [Invoke-ScriptAnalyzer],
                        NullReferenceException
FullyQualifiedErrorId : RULE_ERROR,Microsoft.Windows.PowerShell.ScriptAnalyzer.Commands.InvokeScriptAnalyzerCommand
ErrorDetails          :
InvocationInfo        : System.Management.Automation.InvocationInfo
ScriptStackTrace      : at <ScriptBlock>, E:\Projets\xxx\build.psake.ps1: line 154
                        at Invoke-Task, E:\...\Modules\psake\4.9.0\public\Invoke-Task.ps1: line 108
                        at Invoke-Task, E:\...\Modules\psake\4.9.0\public\Invoke-Task.ps1: line 84
                        at <ScriptBlock>, E:\...\Modules\psake\4.9.0\public\Invoke-psake.ps1: line 303
                        at ExecuteInBuildFileScope,
                        E:\...\Modules\psake\4.9.0\private\ExecuteInBuildFileScope.ps1: line 57
                        at Invoke-psake, E:\...\Modules\psake\4.9.0\public\Invoke-psake.ps1: line 258
                        at <ScriptBlock>, E:\Projets\xxx\build.ps1: line 14
                        at <ScriptBlock>, <No file>: line 1
PipelineIterationInfo : {}


--OR

PSMessageDetails      :
Exception             : System.NullReferenceException: Object reference not set to an instance of an object.
                           at System.Management.Automation.CommandInfo.ResolveParameter(String name)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.Helper.GetExportedFunction(Ast ast)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules.AvoidReservedCharInCmdlet.<AnalyzeScript>d__0.MoveNext()
                           at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
                           at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.ScriptAnalyzer.<>c__DisplayClass83_1.<Analyze
                        SyntaxTree>b__2()
TargetObject          : E:\RELEASES\XXX\Modules\YYY\YYY.psm1
CategoryInfo          : InvalidOperation: (E:\RELEASES\xxx...yyyy.psm1:String) [Invoke-ScriptAnalyzer],
                        NullReferenceException
FullyQualifiedErrorId : RULE_ERROR,Microsoft.Windows.PowerShell.ScriptAnalyzer.Commands.InvokeScriptAnalyzerCommand
ErrorDetails          :
InvocationInfo        : System.Management.Automation.InvocationInfo
ScriptStackTrace      : at <ScriptBlock>, E:\Projets\xxx\build.psake.ps1: line 154
                        at Invoke-Task, E:\SYSTOOLS\XXX\Modules\psake\4.9.0\public\Invoke-Task.ps1: line 108
                        at Invoke-Task, E:\SYSTOOLS\XXX\Modules\psake\4.9.0\public\Invoke-Task.ps1: line 84
                        at <ScriptBlock>, E:\SYSTOOLS\XXX\Modules\psake\4.9.0\public\Invoke-psake.ps1: line 303
                        at ExecuteInBuildFileScope,
                        E:\SYSTOOLS\XXX\Modules\psake\4.9.0\private\ExecuteInBuildFileScope.ps1: line 57
                        at Invoke-psake, E:\SYSTOOLS\XXX\Modules\psake\4.9.0\public\Invoke-psake.ps1: line 258
                        at <ScriptBlock>, E:\Projets\xxxs\build.ps1: line 14
                        at <ScriptBlock>, <No file>: line 1
PipelineIterationInfo : {}

The first three lines are always the same :

Exception             : System.NullReferenceException: Object reference not set to an instance of an object.
                           at System.Management.Automation.CommandInfo.ResolveParameter(String name)
                           at Microsoft.Windows.PowerShell.ScriptAnalyzer.Helper.GetExportedFunction(Ast ast)

The fourth concerns a rule name which can be different :

  at Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules.AvoidReservedCharInCmdlet.<AnalyzeScript>d__0.MoveNext()

The TargetObject property points to a module of the project. The module may not have been modified for several days and may not trigger an error during the previous analysis (10 minutes ago)

Environment data

v5.1  Windows server 2012

> (Get-Module -ListAvailable PSScriptAnalyzer).Version | ForEach-Object { $_.ToString() }
Get-Module

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Manifest   3.1.0.0    Microsoft.PowerShell.Management     {Add-Computer, Add-Content, Checkpoint-Computer, Clear-Con...
Manifest   3.1.0.0    Microsoft.PowerShell.Utility        {Add-Member, Add-Type, Clear-Variable, Compare-Object, Con...
Script     1.0.0.0    posh-git                            {Add-PoshGitToProfile, Expand-GitCommand, Format-GitBranch...
Script     4.9.0      psake                               {Assert, Exec, FormatTaskName, Framework, Get-PSakeScriptT...
Script     2.0.2      PSReadline                          {Get-PSReadLineKeyHandler, Get-PSReadLineOption, Remove-PS...
Script     1.19.0     psscriptanalyzer                    {Get-ScriptAnalyzerRule, Invoke-Formatter, Invoke-ScriptAn...

Test without any error, performed after the error is triggered :

[STA] E:\Projets\XXXs> $error.Clear(); cls;1..20|% {.\build.ps1}

Command line :

$analysisResult = Invoke-ScriptAnalyzer -Path $ModuleOutDir -Settings $ScriptAnalyzerSettingsPath -Recurse -Verbose:($VerbosePreference -eq 'Continue')

#Setting file 
@{
    ExcludeRules = @(
        'PSAvoidGlobalVars', #Legacy
        'PSAvoidUsingWMICmdlet', #Legacy
        'PSAvoidUsingDeprecatedManifestFields',
        'PSMissingModuleManifestField',
        'PSUseToExportFieldsInManifest',
        'PSUseUsingScopeModifierInNewRunspaces',
        'PSReviewUnusedParameter'
    )

    # Check if the scripts uses cmdlets that are compatible PS 3.0,
    Rules = @{
        PSUseCompatibleCommands = @{
            # Turns the rule on
            Enable = $true

            # Lists the PowerShell platforms we want to check compatibility with
            TargetProfiles = @(
                #PowerShell Version 3.0 Operating System Windows Server 2012
                'win-8_x64_6.2.9200.0_3.0_x64_4.0.30319.42000_framework'
            )
        }
    }
}

[rjmholt]

@avezinaATastus that looks like a different issue in this method:

https://github.com/PowerShell/PSScriptAnalyzer/blob/d04c03907b4a4b675bcc3cec3a32cbf3c4ee2d64/Rules/UseShouldProcessCorrectly.cs#L344-L398

Please open a new issue

[LaurentDardenne]

@SydneyhSmith My code having evolved, it no longer causes an error via psake or on the command line. The only thing that differs on the first run is the scan time, but that’s unrelated.

First run 
--------------------------------------------------
Build Time Report
--------------------------------------------------
Name               Duration
----               --------
Init               00:00:00.033
Clean              00:00:00.073
BeforeBuild        00:00:00.001
RemoveConditionnal 00:00:00.000
BeforeStageFiles   00:00:00.001
CoreStageFiles     00:00:00.292
TestBOM            00:00:05.819
TestLocalizedData  00:00:00.000
AfterStageFiles    00:00:00.001
StageFiles         00:00:00.001
Analyze            00:00:40.536        <-------
TestBOMAfterAll    00:00:09.232
AfterBuild         00:00:00.007
Build              00:00:00.001
Total:             00:00:56.163

Next :
-----------------------------------
Build Time Report
-----------------------------------
Name               Duration
----               --------
Init               00:00:00.003
Clean              00:00:00.159
BeforeBuild        00:00:00.002
RemoveConditionnal 00:00:00.000
BeforeStageFiles   00:00:00.001
CoreStageFiles     00:00:00.137
TestBOM            00:00:07.524
TestLocalizedData  00:00:00.000
AfterStageFiles    00:00:00.001
StageFiles         00:00:00.001
Analyze            00:00:01.004      <------
TestBOMAfterAll    00:00:14.883
AfterBuild         00:00:00.004
Build              00:00:00.001
Total:             00:00:23.749

The module was not installed via Install-Module but downloaded from the PS Gallery + ‘XCopy’.