functions/flowcontrol/Stop-PSFFunction.ps1

function Stop-PSFFunction
{
    <#
        .SYNOPSIS
            Function that interrupts a function.
         
        .DESCRIPTION
            Function that interrupts a function.
             
            This function is a utility function used by other functions to reduce error catching overhead.
            It is designed to allow gracefully terminating a function with a warning by default and also allow opt-in into terminating errors.
            It also allows simple integration into loops.
     
            Note:
            When calling this function with the intent to terminate the calling function in non-ExceptionEnabled mode too, you need to add a return below the call.
     
            For a more detailed explanation - including commented full-scale implementation examples - see the associated help article:
            Get-Help about_psf_flowcontrol
         
        .PARAMETER Message
            A message to pass along, explaining just what the error was.
         
        .PARAMETER EnableException
            Replaces user friendly yellow warnings with bloody red exceptions of doom!
            Use this if you want the function to throw terminating errors you want to catch.
         
        .PARAMETER Category
            What category does this termination belong to?
            Is automatically set when passing an error record. Helps with differentiating exceptions without having to resort to text parsing.
         
        .PARAMETER ErrorRecord
            An option to include an inner exception in the error record (and in the exception thrown, if one is thrown).
            Use this, whenever you call Stop-PSFFunction in a catch block.
     
            Note:
            Pass the full error record, not just the exception.
     
        .PARAMETER Tag
            Tags to add to the message written.
            This allows filtering and grouping by category of message, targeting specific messages.
         
        .PARAMETER FunctionName
            The name of the function to crash.
            This parameter is very optional, since it automatically selects the name of the calling function.
            The function name is used as part of the errorid.
            That in turn allows easily figuring out, which exception belonged to which function when checking out the $error variable.
     
        .PARAMETER ModuleName
            The name of the module, the function to be crashed is part of.
            This parameter is very optional, since it automatically selects the name of the calling function.
     
        .PARAMETER File
            The file in which Stop-PSFFunction was called.
            Will be automatically set, but can be overridden when necessary.
         
        .PARAMETER Line
            The line on which Stop-PSFFunction was called.
            Will be automatically set, but can be overridden when necessary.
         
        .PARAMETER Target
            The object that was processed when the error was thrown.
            For example, if you were trying to process a Database Server object when the processing failed, add the object here.
            This object will be in the error record (which will be written, even in non-silent mode, just won't show it).
            If you specify such an object, it becomes simple to actually figure out, just where things failed at.
         
        .PARAMETER Continue
            This will cause the function to call continue while not running with exceptions enabled (-EnableException).
            Useful when mass-processing items where an error shouldn't break the loop.
         
        .PARAMETER SilentlyContinue
            This will cause the function to call continue while running with exceptions enabled (-EnableException).
            Useful when mass-processing items where an error shouldn't break the loop.
         
        .PARAMETER ContinueLabel
            When specifying a label in combination with "-Continue" or "-SilentlyContinue", this function will call continue with this specified label.
            Helpful when trying to continue on an upper level named loop.
     
        .PARAMETER Exception
            Allows specifying an inner exception as input object. This will be passed on to the logging and used for messages.
            When specifying both ErrorRecord AND Exception, Exception wins, but ErrorRecord is still used for record metadata.
     
        .PARAMETER OverrideExceptionMessage
            Disables automatic appending of exception messages.
            Use in cases where you already have a speaking message interpretation and do not need the original message.
     
        .PARAMETER Cmdlet
            The $PSCmdlet object of the calling command.
            Used to write exceptions in a more hidden manner, avoiding exposing internal script text in the default message display.
     
        .PARAMETER StepsUpward
            When not throwing an exception and not calling continue, Stop-PSFFunction signals the calling command to stop.
            In some cases you may want to signal a step or more further up the chain (notably from helper functions within a function).
            This parameter allows you to add additional steps up the callstack that it will notify.
         
        .EXAMPLE
            Stop-PSFFunction -Message "Foo failed bar!" -EnableException $EnableException -ErrorRecord $_
            return
 
            Depending on whether $EnableException is true or false it will:
            - Throw a bloody terminating error. Game over.
            - Write a nice warning about how Foo failed bar, then terminate the function. The return on the next line will then end the calling function.
 
        .EXAMPLE
            Stop-PSFFunction -Message "Foo failed bar!" -EnableException $EnableException -Category InvalidOperation -Target $foo -Continue
 
            Depending on whether $EnableException is true or false it will:
            - Throw a bloody terminating error. Game over.
            - Write a nice warning about how Foo failed bar, then call continue to process the next item in the loop.
            In both cases, the error record added to $error will have the content of $foo added, the better to figure out what went wrong.
    #>

    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSUseShouldProcessForStateChangingFunctions", "")]
    [CmdletBinding(DefaultParameterSetName = 'Plain')]
    param (
        [Parameter(Mandatory = $true)]
        [string]
        $Message,
        
        [bool]
        $EnableException,
        
        [Parameter(ParameterSetName = 'Plain')]
        [Parameter(ParameterSetName = 'Exception')]
        [System.Management.Automation.ErrorCategory]
        $Category = ([System.Management.Automation.ErrorCategory]::NotSpecified),
        
        [Parameter(ParameterSetName = 'Exception')]
        [Alias('InnerErrorRecord')]
        [System.Management.Automation.ErrorRecord[]]
        $ErrorRecord,
        
        [string[]]
        $Tag,
        
        [string]
        $FunctionName,
        
        [string]
        $ModuleName,
        
        [string]
        $File,
        
        [int]
        $Line,
        
        [System.Exception]
        $Exception,
        
        [switch]
        $OverrideExceptionMessage,
        
        [object]
        $Target,
        
        [switch]
        $Continue,
        
        [switch]
        $SilentlyContinue,
        
        [string]
        $ContinueLabel,
        
        [System.Management.Automation.PSCmdlet]
        $Cmdlet,
        
        [int]
        $StepsUpward = 0
    )
    
    if ($Cmdlet) { $myCmdlet = $Cmdlet }
    else { $myCmdlet = $PSCmdlet }
    
    #region Initialize information on the calling command
    $callStack = (Get-PSCallStack)[1]
    if (-not $FunctionName) { $FunctionName = $callStack.Command }
    if (-not $FunctionName) { $FunctionName = "<Unknown>" }
    if (-not $ModuleName) { $ModuleName = $callstack.InvocationInfo.MyCommand.ModuleName }
    if (-not $ModuleName) { $ModuleName = "<Unknown>" }
    if (-not $File) { $File = $callStack.Position.File }
    if (-not $Line) { $Line = $callStack.Position.StartLineNumber }
    #endregion Initialize information on the calling command
    
    #region Apply Transforms
    #region Target Transform
    if ($null -ne $Target)
    {
        $Target = Convert-PsfMessageTarget -Target $Target -FunctionName $FunctionName -ModuleName $ModuleName
    }
    #endregion Target Transform
    
    #region Exception Transforms
    if ($Exception)
    {
        $Exception = Convert-PsfMessageException -Exception $Exception -FunctionName $FunctionName -ModuleName $ModuleName
    }
    elseif ($ErrorRecord)
    {
        $int = 0
        while ($int -lt $ErrorRecord.Length)
        {
            $tempException = Convert-PsfMessageException -Exception $ErrorRecord[$int].Exception -FunctionName $FunctionName -ModuleName $ModuleName
            if ($tempException -ne $ErrorRecord[$int].Exception)
            {
                $ErrorRecord[$int] = New-Object System.Management.Automation.ErrorRecord($tempException, $ErrorRecord[$int].FullyQualifiedErrorId, $ErrorRecord[$int].CategoryInfo.Category, $ErrorRecord[$int].TargetObject)
            }
            
            $int++
        }
    }
    #endregion Exception Transforms
    #endregion Apply Transforms
    
    #region Message Handling
    $records = @()
    
    if ($ErrorRecord -or $Exception)
    {
        if ($ErrorRecord)
        {
            foreach ($record in $ErrorRecord)
            {
                if (-not $Exception) { $newException = New-Object System.Exception($record.Exception.Message, $record.Exception) }
                else { $newException = $Exception }
                if ($record.CategoryInfo.Category) { $Category = $record.CategoryInfo.Category }
                $records += New-Object System.Management.Automation.ErrorRecord($newException, "$($ModuleName)_$FunctionName", $Category, $Target)
            }
        }
        else
        {
            $records += New-Object System.Management.Automation.ErrorRecord($Exception, "$($ModuleName)_$FunctionName", $Category, $Target)
        }
        
        # Manage Debugging
        if ($EnableException) { Write-PSFMessage -Level Warning -Message $Message -EnableException $EnableException -FunctionName $FunctionName -Target $Target -ErrorRecord $records -Tag $Tag -ModuleName $ModuleName -OverrideExceptionMessage:$OverrideExceptionMessage -File $File -Line $Line 3>$null }
        else { Write-PSFMessage -Level Warning -Message $Message -EnableException $EnableException -FunctionName $FunctionName -Target $Target -ErrorRecord $records -Tag $Tag -ModuleName $ModuleName -OverrideExceptionMessage:$OverrideExceptionMessage -File $File -Line $Line }
    }
    else
    {
        $exception = New-Object System.Exception($Message)
        $records += New-Object System.Management.Automation.ErrorRecord($Exception, "$($ModuleName)_$FunctionName", $Category, $Target)
        
        # Manage Debugging
        if ($EnableException) { Write-PSFMessage -Level Warning -Message $Message -EnableException $EnableException -FunctionName $FunctionName -Target $Target -ErrorRecord $records -Tag $Tag -ModuleName $ModuleName -OverrideExceptionMessage:$true -File $File -Line $Line 3>$null }
        else { Write-PSFMessage -Level Warning -Message $Message -EnableException $EnableException -FunctionName $FunctionName -Target $Target -ErrorRecord $records -Tag $Tag -ModuleName $ModuleName -OverrideExceptionMessage:$true -File $File -Line $Line }
    }
    #endregion Message Handling
    
    #region Silent Mode
    if ($EnableException)
    {
        if ($SilentlyContinue)
        {
            foreach ($record in $records) { $myCmdlet.WriteError($record) }
            if ($ContinueLabel) { continue $ContinueLabel }
            else { continue }
        }
        
        # Extra insurance that it'll stop
        $psframework_killqueue.Enqueue($callStack.InvocationInfo.GetHashCode())
        
        # Need to use "throw" as otherwise calling function will not be interrupted without passing the cmdlet parameter
        if (-not $Cmdlet) { throw $records[0] }
        else { $Cmdlet.ThrowTerminatingError($records[0]) }
    }
    #endregion Silent Mode
    
    #region Non-Silent Mode
    else
    {
        # This ensures that the error is stored in the $error variable AND has its Stacktrace (simply adding the record would lack the stacktrace)
        foreach ($record in $records)
        {
            $null = Write-Error -Message $record -Category $Category -TargetObject $Target -Exception $record.Exception -ErrorId "$($ModuleName)_$FunctionName" -ErrorAction Continue 2>&1
        }
        
        if ($Continue)
        {
            if ($ContinueLabel) { continue $ContinueLabel }
            else { continue }
        }
        else
        {
            # Make sure the function knows it should be stopping
            if ($StepsUpward -le 0) { $psframework_killqueue.Enqueue($callStack.InvocationInfo.GetHashCode()) }
            else { $psframework_killqueue.Enqueue((Get-PSCallStack)[($StepsUpward + 1)].InvocationInfo.GetHashCode()) }
            return
        }
    }
    #endregion Non-Silent Mode
}