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New-Object doesn't work with classes in nested modules #2963
Description
Steps to reproduce
- Define some PowerShell classes in a module file (ClassTester.psm1).
- In the manifest, leave RootModule empty and place the module name in the NestedModules key value.
ModuleToProcess = ''
NestedModules = 'ClassTester.psm1'
- In a script, use a Using module statement to import the module and its classes, use the New static method to instantiate one of the classes defined in ClassTester.psm1, and then use New-Object on the same class.
using module ClassTester
$myDog = [Dog]::New('Fido')
$myDog.Bark()
New-Object -TypeName Dog -ArgumentList 'Fluffy'
$myDog.Bark()
Expected behavior
Both the New method and New-Object cmdlet should work.
Actual behavior
New works, but New-Object generates an error.
'Woof!,' said Fido # New method works
New-Object : Cannot find type [Dog]: verify that the assembly containing this type is loaded.
At C:\ps-test\Test-ClassTester.ps1:22 char:11
+ $fluffy = New-Object -TypeName Dog -ArgumentList 'Fluffy'
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidType: (:) [New-Object], PSArgumentException
+ FullyQualifiedErrorId : TypeNotFound,Microsoft.PowerShell.Commands.NewObjectCommand
Environment data
Name Value
---- -----
GitCommitId v6.0.0-alpha.14
PSRemotingProtocolVersion 2.3
BuildVersion 3.0.0.0
WSManStackVersion 3.0
SerializationVersion 1.1.0.1
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
PSVersion 6.0.0-alpha
PSEdition Core
CLRVersion
Activity
xavylon commentedon Jun 14, 2017
Solution: The issue is that you must call the constructor via a method call when you invoke the New-Object cmdlet. See the attached example code.
mklement0 commentedon Apr 14, 2018
xavylon:
There is no syntax issue here:
New-Object -TypeName Dog -ArgumentList 'Fido'is the proper (if verbose) way to call a constructor viaNew-Object; its concise equivalent isNew-Object Dog Fido(yes, the quotes are optional here).In your example,
Dog("Fido")is not a method call; it's a syntax based on a misconception that's unfortunately very common and persists because it just so happens to work:New-Objectis a command and therefore accepts arguments in argument mode, not expression mode (you can only perform method calls in the latter).Dogand("Fido")are therefore separate positional arguments, which bind to-TypeNameand-ArgumentList, respectively.mklement0 commentedon Apr 14, 2018
June Blender (@juneb):
From what I can tell - at least as of PowerShell Core v6.0.2 - even the static
::new()method doesn't see classes from nested modules.It looks like the crux of the issue is that nested modules are imported with the (equivalent of)
Import-Modulerather thanusing, rendering any of the nested module's classes inaccessible - whether via::new()or viaNew-Object.microsoft-github-policy-service commentedon Nov 16, 2023
This issue has not had any activity in 6 months, if this is a bug please try to reproduce on the latest version of PowerShell and reopen a new issue and reference this issue if this is still a blocker for you.
microsoft-github-policy-service commentedon Nov 16, 2023
This issue has not had any activity in 6 months, if this is a bug please try to reproduce on the latest version of PowerShell and reopen a new issue and reference this issue if this is still a blocker for you.
microsoft-github-policy-service commentedon Nov 16, 2023
This issue has not had any activity in 6 months, if this is a bug please try to reproduce on the latest version of PowerShell and reopen a new issue and reference this issue if this is still a blocker for you.
microsoft-github-policy-service commentedon Nov 23, 2023
This issue has been marked as "No Activity" as there has been no activity for 6 months. It has been closed for housekeeping purposes.