Update New-MockObject examples to use type object as input by @fflaten …

…in #2609 (backport to rel/5.x.x) (#2611)

* Add New-MockObject example and tests for internal class

* Wrap test in version check for easier backport

* fix something please

* Add default ctors to make code run under Profiler

* Fix tests for PowerShell 3/4

---------

Co-authored-by: Frode Flaten <3436158+fflaten@users.noreply.github.com>
Co-authored-by: Jakub Jareš <me@jakubjares.com>

src/functions/New-MockObject.ps1

@@ -32,6 +32,10 @@
     .EXAMPLE
     ```powershell
     $obj = New-MockObject -Type 'System.Diagnostics.Process'
+    $obj.GetType().FullName
+        System.Diagnostics.Process
+
+    $obj = New-MockObject -Type ([System.Diagnostics.Process])
     $obj.GetType().FullName
         System.Diagnostics.Process
     ```
@@ -64,6 +68,16 @@
     Create a mock of a process-object and mocks the object's `Kill()`-method. The mocked method will keep a history
     of any call and the associated arguments in a property named `_Kill`
 
+    .EXAMPLE
+    ```powershell
+    $someObj = Get-ObjectFromModule
+    $mock = New-MockObject -Type $someObj.GetType()
+    $mock.GetType().FullName
+        <c2510c5c>.MyInternalClass
+    ```
+
+    Create a mock by providing a TypeInfo, e.g. to mock output using an internal module class.
+
     .LINK
     https://pester.dev/docs/v5/commands/New-MockObject
 

tst/functions/New-MockObject.Tests.ps1

@@ -35,6 +35,31 @@ Describe 'New-MockObject' {
         { New-MockObject $type } | Should -Not -Throw
     }
 
+    It 'Mock using type input' {
+        New-MockObject -Type ([System.Diagnostics.Process]) | Should -BeOfType ([System.Diagnostics.Process])
+    }
+
+    if ($PSVersionTable.PSVersion.Major -ge 5) {
+        It 'Mock internal classes using type' {
+            # Simulate a internal module class like https://github.com/pester/Pester/issues/2564
+            $someObj = & ([scriptblock]::Create('
+                class MyInternalClass {
+                    MyInternalClass() { }
+
+                    [string] $Name = ''Default''
+                    [string] GetName() { return $this.Name }
+                }
+                $obj = [MyInternalClass]::new()
+                $obj.Name = ''Real''
+                $obj'))
+
+            { [MyInternalClass] } | Should -Throw -ErrorId 'TypeNotFound'
+            $mock = New-MockObject -Type $someObj.GetType() -Properties @{ Name = 'Mocked' }
+            $mock.GetType().Name | Should -Be 'MyInternalClass'
+            $mock.GetName() | Should -Be 'Mocked'
+        }
+    }
+
     Context 'Methods' {
         It "Adds a method to the object" {
             $o = New-Object -TypeName 'System.Diagnostics.Process'