dsc/ext/PsOrg/StackExchangeResources/test/unit/StackExchange_Pagefile/pester/StackExchange_Pagefile.Tests.ps1

$ModuleName = (Split-Path -leaf $MyInvocation.MyCommand.Path) -replace '\.[Tt][Ee][Ss][Tt][Ss].[Pp][Ss]1'
$TestsFolder = 1..4 | 
    foreach {$Path = $MyInvocation.MyCommand.Path } {$Path = Split-Path $Path} {$Path}
$RootOfModule = Split-Path $TestsFolder
$CurrentResourceModulePath  = Join-Path $RootOfModule "DscResources/$ModuleName"

Import-Module $CurrentResourceModulePath

InModuleScope $ModuleName {
    Describe 'how Get-TargetResource reponds' {
        Context 'when automatic page file is configured' {
            mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_ComputerSystem'} -mockWith {
                return ([pscustomobject]@{AutomaticManagedPageFile = $true})
            }
            mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_PageFileSetting'} -mockWith {}
            
            $result = Get-TargetResource -initialsize 4GB -MaximumSize 4GB -Ensure 'Present'

            It 'should call once Get-WmiObject Win32_ComputerSystem ' {
                Assert-MockCalled -commandName Get-WmiObject -times 1 -Exactly -parameterFilter {
                    $Class -like 'Win32_ComputerSystem'
                }
            }
            It 'should not call Get-WmiObject Win32_PageFileSetting' {
                Assert-MockCalled -commandName Get-WmiObject -times 0 -Exactly -parameterFilter {
                    $Class -like 'Win32_PageFileSetting'
                }
            }
            It "should return Ensure = 'Absent'" {
                $result['Ensure'] | should be ('Absent')
            }
        }
        Context 'when automatic page file not configured' {
            mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_ComputerSystem'} -mockWith {
                return ([pscustomobject]@{AutomaticManagedPageFile = $false})
            }
            mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_PageFileSetting'} -mockWith {
                return ([pscustomobject]@{
                                            InitialSize = (3GB/1MB)
                                            MaximumSize = (3GB/1MB)
                                        })
            }
            
            $result = Get-TargetResource -initialsize 4GB -MaximumSize 4GB -Ensure 'Present'

            It 'should call once Get-WmiObject Win32_ComputerSystem ' {
                Assert-MockCalled -commandName Get-WmiObject -times 1 -Exactly -parameterFilter {
                    $Class -like 'Win32_ComputerSystem'
                }
            }
            It 'should call once Get-WmiObject Win32_PageFileSetting' {
                Assert-MockCalled -commandName Get-WmiObject -times 1 -Exactly -parameterFilter {
                    $Class -like 'Win32_PageFileSetting'
                }
            }
            It "should return Ensure = 'Present' with Intial and Maximum size at 3GB" {
                $result['Ensure'] | should be ('Present')
                $result['InitialSize'] | should be (3GB)
                $result['MaximumSize'] | should be (3GB)
            }

        }
    }

    Describe 'how Set-TargetResource responds' {

        Context 'when Ensure is set to Absent and AutomaticPageFile is set' {   
            Mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_ComputerSystem'} -mockWith {
                $r = [pscustomobject]@{
                    AutomaticManagedPageFile = $true
                } | Add-Member -MemberType ScriptMethod -Name Put -Value {                                    
                        $global:PutWasCalled = $true  
                        $global:PutValue = $this                
                } -PassThru
                return ($r)
            }  
            $global:PutValue = $null   
            $global:PutWasCalled = $False
            Set-TargetResource -initialsize 4GB -MaximumSize 4GB -Ensure 'Absent'
                    
            It 'should not call put' {
                $global:PutWasCalled | should be ($false)
            }        
        }
        
        Context 'when Ensure is set to Absent and AutomaticPageFile is not set' {   
            Mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_ComputerSystem'} -mockWith {
                $r = [pscustomobject]@{
                    AutomaticManagedPageFile = $false
                } | Add-Member -MemberType ScriptMethod -Name Put -Value {                                    
                        $global:PutWasCalled = $true
                        $global:PutValue = $this                
                } -PassThru
                return ($r)
            }     
            $global:PutValue = $null
            $global:PutWasCalled = $False
            Set-TargetResource -initialsize 4GB -MaximumSize 4GB -Ensure 'Absent'
                    
            It 'should call put' {
                $global:PutWasCalled | should be ($true)
            }
            It 'should set AutomaticManagedPageFile set to $true' {
                $global:PutValue.AutomaticManagedPageFile | should be ($true)
            }        
              
        }
        Context 'when Ensure is set to Absent and AutomaticPageFile is not set' {   
            Mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_ComputerSystem'} -mockWith {
                $r = [pscustomobject]@{ AutomaticManagedPageFile = $false 
                } |
                     Add-Member -MemberType ScriptMethod -Name Put -Value {                                    
                        $global:Win32_ComputerPutWasCalled = $true
                        $global:Win32_ComputerPutValue = $this                
                    } -PassThru
                return ($r)
            }        
            Mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_PageFileSetting'} -mockWith {
                $r = [pscustomobject]@{
                    InitialSize = 0 
                    MaximumSize = 0 
                } | Add-Member -MemberType ScriptMethod -Name Put -Value {                                    
                        $global:Win32_PageFileSettingPutWasCalled = $true
                        $global:Win32_PageFileSettingPutValue = $this                
                } -PassThru
                return ($r)
            }
                 
            $global:Win32_ComputerPutValue = $null
            $global:Win32_ComputerPutWasCalled = $False
            $global:Win32_PageFileSettingPutValue = $null
            $global:Win32_PageFileSettingPutWasCalled = $False

            Set-TargetResource -initialsize 4GB -MaximumSize 4GB -Ensure 'Absent'
                    
            It 'should call put to Win32_ComputerSystem' {
                $global:Win32_ComputerPutWasCalled | should be ($true)
            }
            It 'should set AutomaticManagedPageFile set to $true' {
                $global:Win32_ComputerPutValue.AutomaticManagedPageFile | should be ($true)
            }        
              
        }
        Context 'when Ensure is set to Present and AutomaticPageFile is not set' {   
            Mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_ComputerSystem'} -mockWith {
                $r = [pscustomobject]@{ AutomaticManagedPageFile = $false 
                } |
                     Add-Member -MemberType ScriptMethod -Name Put -Value {                                    
                        $global:Win32_ComputerPutWasCalled = $true
                        $global:PutVWin32_ComputerPutValuealue = $this                
                    } -PassThru
                return ($r)
            }        
            Mock -commandName Get-WmiObject -parameterFilter {$Class -like 'Win32_PageFileSetting'} -mockWith {
                $r = [pscustomobject]@{
                    InitialSize = 0 
                    MaximumSize = 0 
                } | Add-Member -MemberType ScriptMethod -Name Put -Value {                                    
                        $global:Win32_PageFileSettingPutWasCalled = $true
                        $global:Win32_PageFileSettingPutValue = $this                
                } -PassThru
                return ($r)
            }
                 
            $global:Win32_ComputerPutValue = $null
            $global:Win32_ComputerPutWasCalled = $False
            $global:Win32_PageFileSettingPutValue = $null
            $global:Win32_PageFileSettingPutWasCalled = $False

            Set-TargetResource -initialsize 4GB -MaximumSize 4GB -Ensure 'Present'
                    
            It 'should call put on Win32_PageFileSetting' {
                $global:PutWasCalled | should be ($true)
            }
            It 'should not set AutomaticManagedPageFile set to $true' {
                $global:Win32_ComputerPutValue.AutomaticManagedPageFile | should beNullOrEmpty
            }        
            It 'should set Initial and Maximum size to 4 GB' {
                $global:Win32_PageFileSettingPutValue.InitialSize | should be (4gb/1mb)
                $global:Win32_PageFileSettingPutValue.MaximumSize | should be (4gb/1mb)
            }        
              
        }


        Get-Variable -Scope Global -Name Win32_ComputerPutValue | 
            Remove-Variable -Scope Global -Force
        Get-Variable -Scope Global -Name Win32_ComputerPutWasCalled | 
            Remove-Variable -Scope Global -Force
        Get-Variable -Scope Global -Name Win32_PageFileSettingPutValue | 
            Remove-Variable -Scope Global -Force
        Get-Variable -Scope Global -Name Win32_PageFileSettingPutWasCalled | 
            Remove-Variable -Scope Global -Force
    }
}