Invoke-NullCoalescing lies

[wekempf]

I'm not sure why this command is exported publicly? It has nothing to do with Git, and as such I'd prefer it to not be exported, honestly. If you are going to export it, though, it should do what the name says it does.

PS> Invoke-NullCoalescing '' 'oops'
oops
PS> Invoke-NullCoalescing $false 'oops'
oops
PS> Invoke-NullCoalescing 0 'oops'
oops

I'm sure you can think of many other ways to get the wrong result here. However, there is one more example that you may consider correct, but I find to be very confusing.

PS> Invoke-NullCoalescing { } 'oops'
oops

Invoking the ScriptBlocks may be what you need, but it seems very surprising to me. If I were to implement this it would have been simply:

function Invoke-NullCoalescing {
   $args | Where-Object { $_ -ne $null } | Select-Object -First 1
}

To include the script block processing, something like:

function Invoke-NullCoalescing([switch]$ProcessScriptBlocks) {
   $args | ForEach-Object {
        if ($_ -is [ScriptBlock] -and $ProcessScriptBlocks) {
            & $_
        } else {
            $_
        }
    } | Where-Object { $_ -ne $null } | Select-Object -First 1
}

[dahlbyk]

I believe I check for "falsey" rather than $null specifically to handle some places where I deal with git output, but I'm honestly not sure. Lacking tests (something else I'd love to figure out at some point), I'm hesitant to change the behavior.

That said, you're right that exporting it doesn't make sense. I'll fix that.

[kamranayub]

I just got a new W10 Anniversary image on my PC and tried Install-Module posh-git and am now seeing this:

PackageManagement\Install-Package : A command with name
'Invoke-NullCoalescing' is already available on this system.
This module 'posh-git' may override the existing commands.
If you still want to install this module 'posh-git', use
-AllowClobber parameter.
At C:\Program Files\WindowsPowerShell\Modules\PowerShellGet\1 .0.0.1\PSModule.psm1:1661 char:21

Looks like I have this cmdlet already from PSCX that must be installed. I'll keep playing around, but this is the first time I've seen this.

This is PS 5.1.14393

edit: looks like when I restored my old profile and I had also gotten some PS modules we've developed and someone included PSCX and was adding the local paths to my environment bootup--so I removed that bootup sequence and therefore removed the reference to PSCX.

[JCJAT]

1. Cannot install posh-git whilst the Powershell Community extensions (pscx) is installed.
2. posh-git should also not be setting an alias on ??,
3. should it export this function either since it is an internal function only.
4. Manifest for posh-git should have -DefaultCommandPrefix set to prevent conflicts with the users session.

[rkeithhill]

I believe we are planning to not export this function in the 1.0.0 release. It will remain in the upcoming 0.7.0 release as we are trying to avoid potentially breaking changes. The 1.0.0 release however will gives us some latitude WRT breaking changes.

[rkeithhill]

Closed with PR #427