Warning about unused variable in VSCode

[olegstrutinskii]

A wrong warning about unused variable, but that variable used later in code:

[CJHarmath]

+1
I've seen this as well with Insiders build + latest everything. But it's not consistent and sometimes I just have to restart the powershell session

[TylerLeonhardt]

I tried running Script Analyzer on its own against the original repro and I'm seeing the warning. Here's the repro:

In the file repro.ps1:

$a = 0
$b = @(1, 2)
$b | ForEach-Object {
    $a += 1
}
Write-Host $a

in a terminal:

Install-Module -Name PSScriptAnalyzer

Invoke-ScriptAnalyzer -Path path/to/repro.ps1 -Settings PSGallery -Recurse

The output:

RuleName                            Severity     ScriptName Line  Message
--------                            --------     ---------- ----  -------
PSUseDeclaredVarsMoreThanAssignment Warning      repro2.ps1 4     The variable 'a' is assigned but never used.

[mattmcnabb]

I think this warning is appropriate. In your example, $a in the original assignment and the $a inside the foreach block are in two different scopes. Try this:

$a = 1

& {
    $a = 2
}

$a

I don't believe there is an accurate way for PSScriptAnalyzer to guess that your intention is to use the $a variable in the parent scope, and it has to assume that you have assigned an unused variable.

[bergmeister]

There are various issues with false positives of this rule that would probably need to be re-written from the ground up using a different technique to overcome its limitations. I plan to collate all those issues in a meta-issue at some point.

[uSlackr]

Here is my example. $RemoveCount is reported as unused. $RemoveError is not

main loopk in code. Calls functions Remove-member() and Write-Log()

$BaseDir = "C:\Temp\attest"
get-childitem $BaseDir*AttestListing.csv | foreach {
$CSVfile=$

write-log "Processing data file: $($CSVfile.name)" -verbose
$RemoveCount = 0
$RemoveError = $false
import-csv $CSVfile |foreach{
    $line = $_
    if ($line."Remove Member?" -match "[yYxX]") {
        echo "Removing $($line."Member Name") from $($line."Group Name")"
        #write-log "Removing $("$_.Member Name") from $("$_.Group Name")" -verbose
        If (Remove-Member($line)) {
            $RemoveCount = $RemoveCount + 1
        } else {
            $RemoveError = $true
        }
        
    }
}
if ($RemoveError -eq $true){
    Write-log "Error processing changes for: $($CSVFile.fullname)" -verbose
    # If error removing, file is not renamed and must be processed manually
 } else {

    if ($RemoveCount -eq 0) {
        Write-log "No changes processed for $($CSVFile.fullname)" -verbose
    }Else { 
        Write-log "$RemoveCount members removed from $($CSVFile.fullname)" -verbose
    }

    Try {
        Rename-item $CSVfile.fullname "$($CSVFile.basename)_processed.csv"
    }
    Catch {}
}

}

[GuyWicks]

+1

The directive to suppress messages also does not work:

[Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSUseDeclaredVarsMoreThanAssignments","")]

$smtpserver_a = "smtp.example.com"
$smtpserver_b = "smtp.example.com"  < error
$smtpserver_c = "smtp.example.com"  < error
$smtpserver_d = "smtp.example.com"  < error

Anyone know how to suppress this in the visual code settings?