I’m pretty serious when it comes to ensuring the use of Write-Verbose and Write-Warning to their fullest potential in my functions. With that in mind, I’ve come up with a standard way in which I write these types of messages to the screen in warning conditions. In order that I don’t have to track down this code from an actual, already written function the next time I need it, I’ve opted to drop an example, right here. Perhaps it’ll be useful for you, as well.

The idea is that I assign the message I want to convey to a variable, and then use it in the Write-Verbose and Write-Warning commands. That whole use-a-variable concept isn’t what I’m here to discuss; I kind of expect that you put your strings into variables when you plan to use them more than once. The idea is that you can see the full structure I use to inform my users in these types of situations. Have a look at the below example.

...
If (Test-Path -Path $CsvPath) {
    ...
} Else {
    $Warning = "Unable to locate the ""$CsvPath"" path."
    Write-Verbose -Message "$BL Preparing and displaying a warning message."
    Write-Warning -Message $Warning
    Write-Verbose -Message "$BL WARNING: $Warning"
    Write-Verbose -Message "$BL Breaking out of the current function [$CmdType`: $CmdName]."
    break
} # End If.
...

Don’t mind the $BL, $CmdType, and $CmdName variables, as these have everything to do with the advanced function template I’ve written and use for just about everything. They’re not required for this basic code structure.

This simple Warning/Verbose design ensures that Write-Warning messages are captured by Write-Verbose. Once a warning message hits the PowerShell host program, it’s mostly lost. By using the same variable with Write-Verbose, I’m able to do other things with it. As my advanced function template can send Write-Verbose messages to log files, I can therefore ensure warning messages are logged by my functions. This is key.

Anyway, it’s nothing groundbreaking, but I am done looking for an example of this in something I’ve already written, in order to use it in something I’m writing. The two following images are the same example, both in the ISE (Integrated Scripting Environment) and in Visual Studio Code. You can see that when the Verbose parameter is used, we get the warning information included in a verbose message. Therefore, with the use of my advanced function template, I can ensure my warning message makes its way into a log file, if that’s what’s wanted.

And yes, it should’ve included “to,” as in “Unable to locate the…” Ugh, I’m not going to bother recreating these screen captures, even though I’ve updated the above code example.

Of course, all this got me thinking. In some recent projects, I’ve been doing something a bit differently. I’ve been piping my string straight to ForEach-Object, where both Write-Warning and Write-Verbose are executed. Therefore, I suppose the template may end up like it looks below. I’m going to have to think about potentially making this code example my Write-Verbose and Write-Warning template.

...
If (Test-Path -Path $CsvPath) {
    ...
} Else {
    Write-Verbose -Message "$BL Preparing and displaying a warning message."
    "Unable to locate the ""$CsvPath"" path." | ForEach-Object {
        Write-Warning -Message $_; Write-Verbose -Message "$BL WARNING: $_"
    }
    Write-Verbose -Message "$BL Breaking out of the current function [$CmdType`: $CmdName]."
    break
} # End If.
...

Either way, I’ve got this template written down somewhere now, outside of a function.