Not sure if expected behaviour or bug: -hascount of 1 passes on null-values

[OranguTech]

Inadvertantly passing in null/unassigned variables to should -hascount 1 passes!

Issue #1000 seems similar, but I'm not (purposely) using strong typing.

> $AVar = "Bob"                                

> $AVar.count

1
> $avar | should -HaveCount -ExpectedValue 1

> $avar | should -HaveCount -ExpectedValue 2

Expected a collection with size 2, but got collection with size 1 Bob.
At C:\Program Files\WindowsPowerShell\Modules\pester\5.3.0\Pester.psm1:8078 char:13
+             throw $errorRecord
+             ~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidResult: (System.Collecti...,System.Object]:Dictionary`2) [], Exception
    + FullyQualifiedErrorId : PesterAssertionFailed
 
> $nonce -eq $null

True
> $Nonce.count

0
> $Nonce | should -HaveCount -ExpectedValue 1

> $Nonce | should -HaveCount -ExpectedValue 0

Expected an empty collection, but got collection with size 1 @($null).
At C:\Program Files\WindowsPowerShell\Modules\pester\5.3.0\Pester.psm1:8078 char:13
+             throw $errorRecord
+             ~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidResult: (System.Collecti...,System.Object]:Dictionary`2) [], Exception
    + FullyQualifiedErrorId : PesterAssertionFailed
 
$Nonce | should -HaveCount -ExpectedValue 2

Expected a collection with size 2, but got collection with size 1 @($null).
At C:\Program Files\WindowsPowerShell\Modules\pester\5.3.0\Pester.psm1:8078 char:13
+             throw $errorRecord
+             ~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidResult: (System.Collecti...,System.Object]:Dictionary`2) [], Exception
    + FullyQualifiedErrorId : PesterAssertionFailed

I see that since it's getting an (empty) collection is probably why it evaluates as true, but is this expected/wanted? This caused some of my tests to give me false passes, I guess I have to test each var should -Not -BeNullOrEmpty first?

[fflaten]

It's basically the same issue as #1000. PowerShell passes null elements through the pipeline. Should supports pipeline input, but can't know if this was a null that should be ignored or a null element from a collection that it should count.

Until PowerShell lets us know more about the origin of the pipeline, I'm not sure if there's much that can be done.

To properly identify this we'd have to drop pipeline input iirc.