Functions/InModuleScope.ps1
function InModuleScope { <# .SYNOPSIS Allows you to execute parts of a test script within the scope of a PowerShell script module. .DESCRIPTION By injecting some test code into the scope of a PowerShell script module, you can use non-exported functions, aliases and variables inside that module, to perform unit tests on its internal implementation. InModuleScope may be used anywhere inside a Pester script, either inside or outside a Describe block. .PARAMETER ModuleName The name of the module into which the test code should be injected. This module must already be loaded into the current PowerShell session. .PARAMETER ScriptBlock The code to be executed within the script module. .EXAMPLE # The script module: function PublicFunction { # Does something } function PrivateFunction { return $true } Export-ModuleMember -Function PublicFunction # The test script: Import-Module MyModule InModuleScope MyModule { Describe 'Testing MyModule' { It 'Tests the Private function' { PrivateFunction | Should -Be $true } } } Normally you would not be able to access "PrivateFunction" from the PowerShell session, because the module only exported "PublicFunction". Using InModuleScope allowed this call to "PrivateFunction" to work successfully. #> [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [string] $ModuleName, [Parameter(Mandatory = $true)] [scriptblock] $ScriptBlock ) if ($null -eq (& $SafeCommands['Get-Variable'] -Name Pester -ValueOnly -ErrorAction $script:IgnoreErrorPreference)) { # User has executed a test script directly instead of calling Invoke-Pester $Pester = New-PesterState -Path (& $SafeCommands['Resolve-Path'] .) -TestNameFilter $null -TagFilter @() -ExcludeTagFilter @() -SessionState $PSCmdlet.SessionState $script:mockTable = @{} } $module = Get-ScriptModule -ModuleName $ModuleName -ErrorAction Stop $originalState = $Pester.SessionState $originalScriptBlockScope = Get-ScriptBlockScope -ScriptBlock $ScriptBlock try { $Pester.SessionState = $module.SessionState Set-ScriptBlockScope -ScriptBlock $ScriptBlock -SessionState $module.SessionState do { & $ScriptBlock } until ($true) } finally { $Pester.SessionState = $originalState Set-ScriptBlockScope -ScriptBlock $ScriptBlock -SessionStateInternal $originalScriptBlockScope } } function Get-ScriptModule { [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [string] $ModuleName ) try { $modules = @(& $SafeCommands['Get-Module'] -Name $ModuleName -All -ErrorAction Stop) } catch { throw "No module named '$ModuleName' is currently loaded." } $scriptModules = @($modules | & $SafeCommands['Where-Object'] { $_.ModuleType -eq 'Script' }) if ($scriptModules.Count -gt 1) { throw "Multiple Script modules named '$ModuleName' are currently loaded. Make sure to remove any extra copies of the module from your session before testing." } if ($scriptModules.Count -eq 0) { $actualTypes = @( $modules | & $SafeCommands['Where-Object'] { $_.ModuleType -ne 'Script' } | & $SafeCommands['Select-Object'] -ExpandProperty ModuleType -Unique ) $actualTypes = $actualTypes -join ', ' throw "Module '$ModuleName' is not a Script module. Detected modules of the following types: '$actualTypes'" } return $scriptModules[0] } |