Question

I have some code in a powershell function that looks like this:

try {
    Invoke-SomethingThatFails
}
catch [System.Exception] {
    Write-Error $_.Exception.Message;
    return New-Object Namespace.CustomErrorType -Property @{
        'Code' = "Fail";
        "Message" = $_.Exception.Message;
    }
}

Now the only problem is I’d also like to set $? to be $false. Is this possible?

Answer 1

From Bruce Payettes’ PowerShell In Action (Second Edition):

The $? variable will be true if the entire operation succeeded, and
false otherwise. For example, if any of the operations wrote an error
object, then $? will be set to false even if the error was discarded
using redirection. This is an important point: it means that a script
can determine whether an error occurred even if the error isn’t
displayed.

The PowerShell runtime manages the value of $? and is set to false when an error object gets written in the pipeline.

Update Here is how you can write an error object to the pipeline but not terminate it (the pipeline):

function New-Error {
    [CmdletBinding()]
    param()
    $MyErrorRecord = new-object System.Management.Automation.ErrorRecord `
        "", `
        "", `
        ([System.Management.Automation.ErrorCategory]::NotSpecified), `
        ""
    $PSCmdlet.WriteError($MyErrorRecord)
}

$Error.Clear()
Write-Host ('$? before is: ' + $?)
New-Error
Write-Host ('$? after is: ' + $?)

Output:

$? before is: True

New-Error : 
At C:\...\....ps1:14 char:10
+ New-Error <<<< 
    + CategoryInfo          : NotSpecified: (:String) [New-Error], Exception
    + FullyQualifiedErrorId : New-Error

$? after is: False