Functions/Mock.ps1
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function Mock { <# .SYNOPSIS Mocks the behavior of an existing command with an alternate implementation. .DESCRIPTION This creates new behavior for any existing command within the scope of a Describe or Context block. The function allows you to specify a script block that will become the command's new behavior. Optionally, you may create a Parameter Filter which will examine the parameters passed to the mocked command and will invoke the mocked behavior only if the values of the parameter values pass the filter. If they do not, the original command implementation will be invoked instead of a mock. You may create multiple mocks for the same command, each using a different ParameterFilter. ParameterFilters will be evaluated in reverse order of their creation. The last one created will be the first to be evaluated. The mock of the first filter to pass will be used. The exception to this rule are Mocks with no filters. They will always be evaluated last since they will act as a "catch all" mock. Mocks can be marked Verifiable. If so, the Assert-VerifiableMocks command can be used to check if all Verifiable mocks were actually called. If any verifiable mock is not called, Assert-VerifiableMocks will throw an exception and indicate all mocks not called. If you wish to mock commands that are called from inside a script module, you can do so by using the -ModuleName parameter to the Mock command. This injects the mock into the specified module. If you do not specify a module name, the mock will be created in the same scope as the test script. You may mock the same command multiple times, in different scopes, as needed. Each module's mock maintains a separate call history and verified status. .PARAMETER CommandName The name of the command to be mocked. .PARAMETER MockWith A ScriptBlock specifying the behvior that will be used to mock CommandName. The default is an empty ScriptBlock. NOTE: Do not specify param or dynamicparam blocks in this script block. These will be injected automatically based on the signature of the command being mocked, and the MockWith script block can contain references to the mocked commands parameter variables. .PARAMETER Verifiable When this is set, the mock will be checked when Assert-VerifiableMocks is called. .PARAMETER ParameterFilter An optional filter to limit mocking behavior only to usages of CommandName where the values of the parameters passed to the command pass the filter. This ScriptBlock must return a boolean value. See examples for usage. .PARAMETER ModuleName Optional string specifying the name of the module where this command is to be mocked. This should be a module that _calls_ the mocked command; it doesn't necessarily have to be the same module which originally implemented the command. .EXAMPLE Mock Get-ChildItem { return @{FullName = "A_File.TXT"} } Using this Mock, all calls to Get-ChildItem will return a hashtable with a FullName property returning "A_File.TXT" .EXAMPLE Mock Get-ChildItem { return @{FullName = "A_File.TXT"} } -ParameterFilter { $Path -and $Path.StartsWith($env:temp) } This Mock will only be applied to Get-ChildItem calls within the user's temp directory. .EXAMPLE Mock Set-Content {} -Verifiable -ParameterFilter { $Path -eq "some_path" -and $Value -eq "Expected Value" } When this mock is used, if the Mock is never invoked and Assert-VerifiableMocks is called, an exception will be thrown. The command behavior will do nothing since the ScriptBlock is empty. .EXAMPLE Mock Get-ChildItem { return @{FullName = "A_File.TXT"} } -ParameterFilter { $Path -and $Path.StartsWith($env:temp\1) } Mock Get-ChildItem { return @{FullName = "B_File.TXT"} } -ParameterFilter { $Path -and $Path.StartsWith($env:temp\2) } Mock Get-ChildItem { return @{FullName = "C_File.TXT"} } -ParameterFilter { $Path -and $Path.StartsWith($env:temp\3) } Multiple mocks of the same command may be used. The parameter filter determines which is invoked. Here, if Get-ChildItem is called on the "2" directory of the temp folder, then B_File.txt will be returned. .EXAMPLE Mock Get-ChildItem { return @{FullName="B_File.TXT"} } -ParameterFilter { $Path -eq "$env:temp\me" } Mock Get-ChildItem { return @{FullName="A_File.TXT"} } -ParameterFilter { $Path -and $Path.StartsWith($env:temp) } Get-ChildItem $env:temp\me Here, both mocks could apply since both filters will pass. A_File.TXT will be returned because it was the most recent Mock created. .EXAMPLE Mock Get-ChildItem { return @{FullName = "B_File.TXT"} } -ParameterFilter { $Path -eq "$env:temp\me" } Mock Get-ChildItem { return @{FullName = "A_File.TXT"} } Get-ChildItem c:\windows Here, A_File.TXT will be returned. Since no filter was specified, it will apply to any call to Get-ChildItem that does not pass another filter. .EXAMPLE Mock Get-ChildItem { return @{FullName = "B_File.TXT"} } -ParameterFilter { $Path -eq "$env:temp\me" } Mock Get-ChildItem { return @{FullName = "A_File.TXT"} } Get-ChildItem $env:temp\me Here, B_File.TXT will be returned. Even though the filterless mock was created more recently. This illustrates that filterless Mocks are always evaluated last regardlss of their creation order. .EXAMPLE Mock Get-ChildItem { return @{FullName = "A_File.TXT"} } -ModuleName MyTestModule Using this Mock, all calls to Get-ChildItem from within the MyTestModule module will return a hashtable with a FullName property returning "A_File.TXT" .EXAMPLE Get-Module -Name ModuleMockExample | Remove-Module New-Module -Name ModuleMockExample -ScriptBlock { function Hidden { "Internal Module Function" } function Exported { Hidden } Export-ModuleMember -Function Exported } | Import-Module -Force Describe "ModuleMockExample" { It "Hidden function is not directly accessible outside the module" { { Hidden } | Should Throw } It "Original Hidden function is called" { Exported | Should Be "Internal Module Function" } It "Hidden is replaced with our implementation" { Mock Hidden { "Mocked" } -ModuleName ModuleMockExample Exported | Should Be "Mocked" } } This example shows how calls to commands made from inside a module can be mocked by using the -ModuleName parameter. .LINK Assert-MockCalled Assert-VerifiableMocks Describe Context It about_Should about_Mocking #> param( [string]$CommandName, [ScriptBlock]$MockWith={}, [switch]$Verifiable, [ScriptBlock]$ParameterFilter = {$True}, [string]$ModuleName ) Assert-DescribeInProgress -CommandName Mock $contextInfo = Validate-Command $CommandName $ModuleName $CommandName = $contextInfo.Command.Name if ($contextInfo.Session.Module -and $contextInfo.Session.Module.Name) { $ModuleName = $contextInfo.Session.Module.Name } else { $ModuleName = '' } $mockWithCopy = [scriptblock]::Create($MockWith.ToString()) Set-ScriptBlockScope -ScriptBlock $mockWithCopy -SessionState $contextInfo.Session $block = @{ Mock = $mockWithCopy Filter = $ParameterFilter Verifiable = $Verifiable Scope = Get-ScopeForMock -PesterState $pester } $mock = $mockTable["$ModuleName||$CommandName"] if (-not $mock) { $metadata = $null $cmdletBinding = '' $paramBlock = '' $dynamicParamBlock = '' $dynamicParamScriptBlock = $null if ($contextInfo.Command.psobject.Properties['ScriptBlock'] -or $contextInfo.Command.CommandType -eq 'Cmdlet') { $metadata = [System.Management.Automation.CommandMetaData]$contextInfo.Command $null = $metadata.Parameters.Remove('Verbose') $null = $metadata.Parameters.Remove('Debug') $null = $metadata.Parameters.Remove('ErrorAction') $null = $metadata.Parameters.Remove('WarningAction') $null = $metadata.Parameters.Remove('ErrorVariable') $null = $metadata.Parameters.Remove('WarningVariable') $null = $metadata.Parameters.Remove('OutVariable') $null = $metadata.Parameters.Remove('OutBuffer') $cmdletBinding = [Management.Automation.ProxyCommand]::GetCmdletBindingAttribute($metadata) $paramBlock = [Management.Automation.ProxyCommand]::GetParamBlock($metadata) if ($contextInfo.Command.CommandType -eq 'Cmdlet') { $dynamicParamBlock = "dynamicparam { Get-MockDynamicParameters -CmdletName '$($contextInfo.Command.Name)' -Parameters `$PSBoundParameters }" } else { $dynamicParamStatements = Get-DynamicParamBlock -ScriptBlock $contextInfo.Command.ScriptBlock if ($dynamicParamStatements -match '\S') { $metadataSafeForDynamicParams = [System.Management.Automation.CommandMetaData]$contextInfo.Command foreach ($parameter in $metadataSafeForDynamicParams.Parameters.Values) { $parameter.ParameterSets.Clear() } $paramBlockSafeForDynamicParams = [System.Management.Automation.ProxyCommand]::GetParamBlock($metadataSafeForDynamicParams) $comma = if ($metadataSafeForDynamicParams.Parameters.Count -gt 0) { ',' } else { '' } $dynamicParamBlock = "dynamicparam { Get-MockDynamicParameters -ModuleName '$ModuleName' -FunctionName '$CommandName' -Parameters `$PSBoundParameters -Cmdlet `$PSCmdlet }" $code = @" $cmdletBinding param( [object] `${P S Cmdlet}$comma $paramBlockSafeForDynamicParams ) `$PSCmdlet = `${P S Cmdlet} $dynamicParamStatements "@ $dynamicParamScriptBlock = [scriptblock]::Create($code) $sessionStateInternal = Get-ScriptBlockScope -ScriptBlock $contextInfo.Command.ScriptBlock if ($null -ne $sessionStateInternal) { Set-ScriptBlockScope -ScriptBlock $dynamicParamScriptBlock -SessionStateInternal $sessionStateInternal } } } } $newContent = Microsoft.PowerShell.Management\Get-Content function:\MockPrototype $newContent = $newContent -replace '#FUNCTIONNAME#', $CommandName $newContent = $newContent -replace '#MODULENAME#', $ModuleName $mockScript = [scriptblock]::Create("$cmdletBinding`r`nparam( $paramBlock )`r`n$dynamicParamBlock`r`nprocess{`r`n$newContent}") $mock = @{ OriginalCommand = $contextInfo.Command Blocks = @() CommandName = $CommandName SessionState = $contextInfo.Session Scope = $pester.Scope Metadata = $metadata CallHistory = @() DynamicParamScriptBlock = $dynamicParamScriptBlock FunctionScope = '' } $mockTable["$ModuleName||$CommandName"] = $mock if ($contextInfo.Command.CommandType -eq 'Function') { $mock['FunctionScope'] = $contextInfo.Scope $scriptBlock = { param ( [string] $CommandName ) if ($ExecutionContext.InvokeProvider.Item.Exists("Function:\$CommandName")) { $ExecutionContext.InvokeProvider.Item.Rename("Function:\$CommandName", "script:PesterIsMocking_$CommandName", $true) } } $null = Invoke-InMockScope -SessionState $mock.SessionState -ScriptBlock $scriptBlock -ArgumentList $CommandName } $scriptBlock = { $ExecutionContext.InvokeProvider.Item.Set("Function:\script:$($args[0])", $args[1], $true, $true) } $null = Invoke-InMockScope -SessionState $mock.SessionState -ScriptBlock $scriptBlock -ArgumentList $CommandName, $mockScript } $mock.Blocks = @( $mock.Blocks | Where-Object { $_.Filter.ToString() -eq '$True' } if ($block.Filter.ToString() -eq '$True') { $block } $mock.Blocks | Where-Object { $_.Filter.ToString() -ne '$True' } if ($block.Filter.ToString() -ne '$True') { $block } ) } function Assert-VerifiableMocks { <# .SYNOPSIS Checks if any Verifiable Mock has not been invoked. If so, this will throw an exception. .DESCRIPTION This can be used in tandem with the -Verifiable switch of the Mock function. Mock can be used to mock the behavior of an existing command and optionally take a -Verifiable switch. When Assert-VerifiableMocks is called, it checks to see if any Mock marked Verifiable has not been invoked. If any mocks have been found that specified -Verifiable and have not been invoked, an exception will be thrown. .EXAMPLE Mock Set-Content {} -Verifiable -ParameterFilter {$Path -eq "some_path" -and $Value -eq "Expected Value"} { ...some code that never calls Set-Content some_path -Value "Expected Value"... } Assert-VerifiableMocks This will throw an exception and cause the test to fail. .EXAMPLE Mock Set-Content {} -Verifiable -ParameterFilter {$Path -eq "some_path" -and $Value -eq "Expected Value"} Set-Content some_path -Value "Expected Value" Assert-VerifiableMocks This will not throw an exception because the mock was invoked. #> Assert-DescribeInProgress -CommandName Assert-VerifiableMocks $unVerified=@{} $mockTable.Keys | % { $m=$_; $mockTable[$m].blocks | ? { $_.Verifiable } | % { $unVerified[$m]=$_ } } if($unVerified.Count -gt 0) { foreach($mock in $unVerified.Keys){ $array = $mock -split '\|\|' $function = $array[1] $module = $array[0] $message = "`r`n Expected $function " if ($module) { $message += "in module $module " } $message += "to be called with $($unVerified[$mock].Filter)" } throw $message } } function Assert-MockCalled { <# .SYNOPSIS Checks if a Mocked command has been called a certain number of times and throws an exception if it has not. .DESCRIPTION This command verifies that a mocked command has been called a certain number of times. If the call history of the mocked command does not match the parameters passed to Assert-MockCalled, Assert-MockCalled will throw an exception. .PARAMETER CommandName The mocked command whose call history should be checked. .PARAMETER ModuleName The module where the mock being checked was injected. This is optional, and must match the ModuleName that was used when setting up the Mock. .PARAMETER Times The number of times that the mock must be called to avoid an exception from throwing. .PARAMETER Exactly If this switch is present, the number specified in Times must match exactly the number of times the mock has been called. Otherwise it must match "at least" the number of times specified. If the value passed to the Times parameter is zero, the Exactly switch is implied. .PARAMETER ParameterFilter An optional filter to qualify wich calls should be counted. Only those calls to the mock whose parameters cause this filter to return true will be counted. .PARAMETER ExlusiveFilter Like ParameterFilter, except when you use ExclusiveFilter, and there were any calls to the mocked command which do not match the filter, an exception will be thrown. This is a convenient way to avoid needing to have two calls to Assert-MockCalled like this: Assert-MockCalled SomeCommand -Times 1 -ParameterFilter { $something -eq $true } Assert-MockCalled SomeCommand -Times 0 -ParameterFilter { $something -ne $true } .PARAMETER Scope An optional parameter specifying the Pester scope in which to check for calls to the mocked command. By default, Assert-MockCalled will find all calls to the mocked command in the current Context block (if present), or the current Describe block (if there is no active Context.) Valid values are Describe, Context and It. If you use a scope of Describe or Context, the command will identify all calls to the mocked command in the current Describe / Context block, as well as all child scopes of that block. .EXAMPLE C:\PS>Mock Set-Content {} {... Some Code ...} C:\PS>Assert-MockCalled Set-Content This will throw an exception and cause the test to fail if Set-Content is not called in Some Code. .EXAMPLE C:\PS>Mock Set-Content -parameterFilter {$path.StartsWith("$env:temp\")} {... Some Code ...} C:\PS>Assert-MockCalled Set-Content 2 { $path -eq "$env:temp\test.txt" } This will throw an exception if some code calls Set-Content on $path=$env:temp\test.txt less than 2 times .EXAMPLE C:\PS>Mock Set-Content {} {... Some Code ...} C:\PS>Assert-MockCalled Set-Content 0 This will throw an exception if some code calls Set-Content at all .EXAMPLE C:\PS>Mock Set-Content {} {... Some Code ...} C:\PS>Assert-MockCalled Set-Content -Exactly 2 This will throw an exception if some code does not call Set-Content Exactly two times. .EXAMPLE Describe 'Assert-MockCalled Scope behavior' { Mock Set-Content { } It 'Calls Set-Content at least once in the It block' { {... Some Code ...} Assert-MockCalled Set-Content -Exactly 0 -Scope It } } Checks for calls only within the current It block. .EXAMPLE Describe 'Describe' { Mock -ModuleName SomeModule Set-Content { } {... Some Code ...} It 'Calls Set-Content at least once in the Describe block' { Assert-MockCalled -ModuleName SomeModule Set-Content } } Checks for calls to the mock within the SomeModule module. Note that both the Mock and Assert-MockCalled commands use the same module name. .EXAMPLE Assert-MockCalled Get-ChildItem -ExclusiveFilter { $Path -eq 'C:\' } Checks to make sure that Get-ChildItem was called at least one time with the -Path parameter set to 'C:\', and that it was not called at all with the -Path parameter set to any other value. .NOTES The parameter filter passed to Assert-MockCalled does not necessarily have to match the parameter filter (if any) which was used to create the Mock. Assert-MockCalled will find any entry in the command history which matches its parameter filter, regardless of how the Mock was created. However, if any calls to the mocked command are made which did not match any mock's parameter filter (resulting in the original command being executed instead of a mock), these calls to the original command are not tracked in the call history. In other words, Assert-MockCalled can only be used to check for calls to the mocked implementation, not to the original. #> [CmdletBinding(DefaultParameterSetName = 'ParameterFilter')] param( [Parameter(Mandatory = $true, Position = 0)] [string]$CommandName, [Parameter(Position = 1)] [int]$Times=1, [Parameter(ParameterSetName = 'ParameterFilter', Position = 2)] [ScriptBlock]$ParameterFilter = {$True}, [Parameter(ParameterSetName = 'ExclusiveFilter', Mandatory = $true)] [scriptblock] $ExclusiveFilter, [Parameter(Position = 3)] [string] $ModuleName, [Parameter(Position = 4)] [ValidateSet('Describe','Context','It')] [string] $Scope, [switch]$Exactly ) if ($PSCmdlet.ParameterSetName -eq 'ParameterFilter') { $filter = $ParameterFilter $filterIsExclusive = $false } else { $filter = $ExclusiveFilter $filterIsExclusive = $true } Assert-DescribeInProgress -CommandName Assert-MockCalled if (-not $PSBoundParameters.ContainsKey('ModuleName') -and $null -ne $pester.SessionState.Module) { $ModuleName = $pester.SessionState.Module.Name } $mock = $script:mockTable["$ModuleName||$commandName"] $moduleMessage = '' if ($ModuleName) { $moduleMessage = " in module $ModuleName" } if (-not $mock) { throw "You did not declare a mock of the $commandName Command${moduleMessage}." } if (-not $Scope) { if ($pester.CurrentContext) { $Scope = 'Context' } else { $Scope = 'Describe' } } $matchingCalls = New-Object System.Collections.ArrayList $nonMatchingCalls = New-Object System.Collections.ArrayList foreach ($historyEntry in $mock.CallHistory) { if (-not (Test-MockCallScope -CallScope $historyEntry.Scope -DesiredScope $Scope)) { continue } $params = @{ ScriptBlock = $filter BoundParameters = $historyEntry.BoundParams ArgumentList = $historyEntry.Args Metadata = $mock.Metadata } if (Test-ParameterFilter @params) { $null = $matchingCalls.Add($historyEntry) } else { $null = $nonMatchingCalls.Add($historyEntry) } } $lineText = $MyInvocation.Line.TrimEnd("`n") $line = $MyInvocation.ScriptLineNumber if($matchingCalls.Count -ne $times -and ($Exactly -or ($times -eq 0))) { $failureMessage = "Expected ${commandName}${moduleMessage} to be called $times times exactly but was called $($matchingCalls.Count) times" throw ( New-ShouldErrorRecord -Message $failureMessage -Line $line -LineText $lineText) } elseif($matchingCalls.Count -lt $times) { $failureMessage = "Expected ${commandName}${moduleMessage} to be called at least $times times but was called $($matchingCalls.Count) times" throw ( New-ShouldErrorRecord -Message $failureMessage -Line $line -LineText $lineText) } elseif ($filterIsExclusive -and $nonMatchingCalls.Count -gt 0) { $failureMessage = "Expected ${commandName}${moduleMessage} to only be called with with parameters matching the specified filter, but $($nonMatchingCalls.Count) non-matching calls were made" throw ( New-ShouldErrorRecord -Message $failureMessage -Line $line -LineText $lineText) } } function Test-MockCallScope { [CmdletBinding()] param ( [string] $CallScope, [string] $DesiredScope ) # It would probably be cleaner to replace all of these scope strings with an enumerated type at some point. $scopes = 'Describe', 'Context', 'It' return ([array]::IndexOf($scopes, $CallScope) -ge [array]::IndexOf($scopes, $DesiredScope)) } function Exit-MockScope { if ($null -eq $mockTable) { return } $currentScope = $pester.Scope $parentScope = $pester.ParentScope $scriptBlock = { param ( [string] $CommandName, [string] $Scope ) $ExecutionContext.InvokeProvider.Item.Remove("Function:\$CommandName", $false, $true, $true) if ($ExecutionContext.InvokeProvider.Item.Exists("Function:\PesterIsMocking_$CommandName", $true, $true)) { $ExecutionContext.InvokeProvider.Item.Rename("Function:\PesterIsMocking_$CommandName", "$Scope$CommandName", $true) } } $mockKeys = [string[]]$mockTable.Keys foreach ($mockKey in $mockKeys) { $mock = $mockTable[$mockKey] $mock.Blocks = @($mock.Blocks | Where {$_.Scope -ne $currentScope}) if ($null -eq $parentScope) { $null = Invoke-InMockScope -SessionState $mock.SessionState -ScriptBlock $scriptBlock -ArgumentList $mock.CommandName, $mock.FunctionScope $mockTable.Remove($mockKey) } else { foreach ($historyEntry in $mock.CallHistory) { if ($historyEntry.Scope -eq $currentScope) { $historyEntry.Scope = $parentScope } } } } } function Validate-Command([string]$CommandName, [string]$ModuleName) { $module = $null $origCommand = $null $commandInfo = New-Object psobject -Property @{ Command = $null; Scope = '' } $scriptBlock = { $command = $ExecutionContext.InvokeCommand.GetCommand($args[0], 'All') while ($null -ne $command -and $command.CommandType -eq [System.Management.Automation.CommandTypes]::Alias) { $command = $command.ResolvedCommand } $properties = @{ Command = $command } if ($null -ne $command -and $command.CommandType -eq 'Function') { if ($ExecutionContext.InvokeProvider.Item.Exists("function:\global:$($command.Name)") -and (Microsoft.PowerShell.Management\Get-Content "function:\global:$($command.Name)" -ErrorAction Stop) -eq $command.ScriptBlock) { $properties['Scope'] = 'global:' } elseif ($ExecutionContext.InvokeProvider.Item.Exists("function:\script:$($command.Name)") -and (Microsoft.PowerShell.Management\Get-Content "function:\script:$($command.Name)" -ErrorAction Stop) -eq $command.ScriptBlock) { $properties['Scope'] = 'script:' } else { $properties['Scope'] = '' } } return New-Object psobject -Property $properties } if ($ModuleName) { $module = Get-ScriptModule -ModuleName $ModuleName -ErrorAction Stop $commandInfo = & $module $scriptBlock $CommandName } $session = $pester.SessionState if (-not $commandInfo.Command) { Set-ScriptBlockScope -ScriptBlock $scriptBlock -SessionState $session $commandInfo = & $scriptBlock $commandName } if (-not $commandInfo.Command) { throw ([System.Management.Automation.CommandNotFoundException] "Could not find Command $commandName") } if ($module) { $session = & $module { $ExecutionContext.SessionState } } $hash = @{Command = $commandInfo.Command; Session = $session} if ($commandInfo.Command.CommandType -eq 'Function') { $hash['Scope'] = $commandInfo.Scope } return $hash } function MockPrototype { if ($PSVersionTable.PSVersion.Major -ge 3) { [string] ${ignore preference} = 'Ignore' } else { [string] ${ignore preference} = 'SilentlyContinue' } [object] ${a r g s} = Get-Variable -Name args -ValueOnly -Scope Local -ErrorAction ${ignore preference} if ($null -eq ${a r g s}) { ${a r g s} = @() } ${p s cmdlet} = Get-Variable -Name PSCmdlet -ValueOnly -Scope Local -ErrorAction ${ignore preference} ${session state} = if (${p s cmdlet}) { ${p s cmdlet}.SessionState } Invoke-Mock -CommandName '#FUNCTIONNAME#' -ModuleName '#MODULENAME#' -BoundParameters $PSBoundParameters -ArgumentList ${a r g s} -CallerSessionState ${session state} } function Invoke-Mock { <# .SYNOPSIS This command is used by Pester's Mocking framework. You do not need to call it directly. #> [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [string] $CommandName, [string] $ModuleName, [hashtable] $BoundParameters = @{}, [object[]] $ArgumentList = @(), [object] $CallerSessionState ) if ($mock = $mockTable["$ModuleName||$CommandName"]) { for ($idx = $mock.Blocks.Length; $idx -gt 0; $idx--) { $block = $mock.Blocks[$idx - 1] $params = @{ ScriptBlock = $block.Filter BoundParameters = $BoundParameters ArgumentList = $ArgumentList Metadata = $mock.Metadata } if (Test-ParameterFilter @params) { $block.Verifiable = $false $mock.CallHistory += @{CommandName = "$ModuleName||$CommandName"; BoundParams = $BoundParameters; Args = $ArgumentList; Scope = $pester.Scope } $scriptBlock = { param ( [Parameter(Mandatory = $true)] [scriptblock] $ScriptBlock, [hashtable] $BoundParameters = @{}, [object[]] $ArgumentList = @(), [System.Management.Automation.CommandMetadata] $Metadata, [System.Management.Automation.SessionState] $SessionState ) # This script block exists to hold variables without polluting the test script's current scope. # Dynamic parameters in functions, for some reason, only exist in $PSBoundParameters instead # of being assigned a local variable the way static parameters do. By calling Set-DynamicParameterValues, # we create these variables for the caller's use in a Parameter Filter or within the mock itself, and # by doing it inside this temporary script block, those variables don't stick around longer than they # should. # Because Set-DynamicParameterVariables might potentially overwrite our $ScriptBlock, $BoundParameters and/or $ArgumentList variables, # we'll stash them in names unlikely to be overwritten. $___ScriptBlock___ = $ScriptBlock $___BoundParameters___ = $BoundParameters $___ArgumentList___ = $ArgumentList Set-DynamicParameterVariables -SessionState $SessionState -Parameters $BoundParameters -Metadata $Metadata & $___ScriptBlock___ @___BoundParameters___ @___ArgumentList___ } Set-ScriptBlockScope -ScriptBlock $scriptBlock -SessionState $mock.SessionState & $scriptBlock -ScriptBlock $block.Mock -ArgumentList $ArgumentList -BoundParameters $BoundParameters -Metadata $mock.Metadata -SessionState $mock.SessionState return } } $scriptBlock = { param ($Command, $ArgumentList, $BoundParameters) & $Command @ArgumentList @BoundParameters } $state = if ($CallerSessionState) { $CallerSessionState } else { $mock.SessionState } Set-ScriptBlockScope -ScriptBlock $scriptBlock -SessionState $state & $scriptBlock -Command $mock.OriginalCommand -ArgumentList $ArgumentList -BoundParameters $BoundParameters } elseif ($mock = $mockTable["||$CommandName"]) { # This situation can happen if the test script is dot-sourced in the global scope. Under these conditions, # a module can wind up executing Invoke-Mock when that was not the intent of the test. Try to recover from # this by executing the original command. $scriptBlock = { param ($Command, $ArgumentList, $BoundParameters) & $Command @ArgumentList @BoundParameters } $state = if ($CallerSessionState) { $CallerSessionState } else { $mock.SessionState } Set-ScriptBlockScope -ScriptBlock $scriptBlock -SessionState $state & $scriptBlock -Command $mock.OriginalCommand -ArgumentList $ArgumentList -BoundParameters $BoundParameters } else { # If this ever happens, it's a bug in Pester. The scriptBlock that calls Invoke-Mock should be removed at the same time as the entry in the mock table. throw "Internal error detected: Mock for '$CommandName' in module '$ModuleName' was called, but does not exist in the mock table." } } function Invoke-InMockScope { [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [System.Management.Automation.SessionState] $SessionState, [Parameter(Mandatory = $true)] [scriptblock] $ScriptBlock, [Parameter(ValueFromRemainingArguments = $true)] [object[]] $ArgumentList = @() ) if ($SessionState.Module) { $SessionState.Module.Invoke($ScriptBlock, $ArgumentList) } else { Set-ScriptBlockScope -ScriptBlock $ScriptBlock -SessionState $SessionState & $ScriptBlock @ArgumentList } } function Test-ParameterFilter { [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [scriptblock] $ScriptBlock, [System.Collections.IDictionary] $BoundParameters, [object[]] $ArgumentList, [System.Management.Automation.CommandMetadata] $Metadata ) if ($null -eq $BoundParameters) { $BoundParameters = @{} } if ($null -eq $ArgumentList) { $ArgumentList = @() } $paramBlock = Get-ParamBlockFromBoundParameters -BoundParameters $BoundParameters -Metadata $Metadata $scriptBlockString = " $paramBlock Set-StrictMode -Off $ScriptBlock " $cmd = [scriptblock]::Create($scriptBlockString) Set-ScriptBlockScope -ScriptBlock $cmd -SessionState $pester.SessionState & $cmd @BoundParameters @ArgumentList } function Get-ParamBlockFromBoundParameters { param ( [System.Collections.IDictionary] $BoundParameters, [System.Management.Automation.CommandMetadata] $Metadata ) $params = foreach ($paramName in $BoundParameters.Keys) { if (IsCommonParameter -Name $paramName -Metadata $Metadata) { continue } "`${$paramName}" } $params = $params -join ',' if ($null -ne $Metadata) { $cmdletBinding = [System.Management.Automation.ProxyCommand]::GetCmdletBindingAttribute($Metadata) } else { $cmdletBinding = '' } return "$cmdletBinding param ($params)" } function IsCommonParameter { param ( [string] $Name, [System.Management.Automation.CommandMetadata] $Metadata ) if ($null -ne $Metadata) { if ([System.Management.Automation.Internal.CommonParameters].GetProperty($Name)) { return $true } if ($Metadata.SupportsShouldProcess -and [System.Management.Automation.Internal.ShouldProcessParameters].GetProperty($Name)) { return $true } if ($PSVersionTable.PSVersion.Major -ge 3 -and $Metadata.SupportsPaging -and [System.Management.Automation.PagingParameters].GetProperty($Name)) { return $true } if ($Metadata.SupportsTransactions -and [System.Management.Automation.Internal.TransactionParameters].GetProperty($Name)) { return $true } } return $false } function Get-ScopeForMock { param ($PesterState) $scope = $PesterState.Scope if ($scope -eq 'It') { $scope = $PesterState.ParentScope } return $scope } function Set-DynamicParameterVariables { <# .SYNOPSIS This command is used by Pester's Mocking framework. You do not need to call it directly. #> param ( [Parameter(Mandatory = $true)] [System.Management.Automation.SessionState] $SessionState, [hashtable] $Parameters, [System.Management.Automation.CommandMetadata] $Metadata ) if ($null -eq $Parameters) { $Parameters = @{} } foreach ($keyValuePair in $Parameters.GetEnumerator()) { $variableName = $keyValuePair.Key if (-not (IsCommonParameter -Name $variableName -Metadata $Metadata)) { if ($ExecutionContext.SessionState -eq $SessionState) { Set-Variable -Scope 1 -Name $variableName -Value $keyValuePair.Value -Force -Confirm:$false -WhatIf:$false } else { $SessionState.PSVariable.Set($variableName, $keyValuePair.Value) } } } } function Get-DynamicParamBlock { param ( [scriptblock] $ScriptBlock ) if ($PSVersionTable.PSVersion.Major -le 2) { $flags = [System.Reflection.BindingFlags]'Instance, NonPublic' $dynamicParams = [scriptblock].GetField('_dynamicParams', $flags).GetValue($ScriptBlock) if ($null -ne $dynamicParams) { return $dynamicParams.ToString() } } else { if ($null -ne $ScriptBlock.Ast.Body.DynamicParamBlock) { $statements = $ScriptBlock.Ast.Body.DynamicParamBlock.Statements | Select-Object -ExpandProperty Extent | Select-Object -ExpandProperty Text return $statements -join "`r`n" } } } function Get-MockDynamicParameters { <# .SYNOPSIS This command is used by Pester's Mocking framework. You do not need to call it directly. #> [CmdletBinding()] param ( [Parameter(Mandatory = $true, ParameterSetName = 'Cmdlet')] [string] $CmdletName, [Parameter(Mandatory = $true, ParameterSetName = 'Function')] [string] $FunctionName, [Parameter(ParameterSetName = 'Function')] [string] $ModuleName, [hashtable] $Parameters, [object] $Cmdlet ) switch ($PSCmdlet.ParameterSetName) { 'Cmdlet' { Get-DynamicParametersForCmdlet -CmdletName $CmdletName -Parameters $Parameters } 'Function' { Get-DynamicParametersForMockedFunction -FunctionName $FunctionName -ModuleName $ModuleName -Parameters $Parameters -Cmdlet $Cmdlet } } } function Get-DynamicParametersForCmdlet { [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [string] $CmdletName, [System.Collections.IDictionary] $Parameters ) if ($null -eq $Parameters) { $Parameters = @{} } try { $command = Get-Command -Name $CmdletName -CommandType Cmdlet -ErrorAction Stop if (@($command).Count -gt 1) { throw "Name '$CmdletName' resolved to multiple Cmdlets" } } catch { $PSCmdlet.ThrowTerminatingError($_) } $cmdlet = Microsoft.PowerShell.Utility\New-Object $command.ImplementingType.FullName if ($cmdlet -isnot [System.Management.Automation.IDynamicParameters]) { return } $flags = [System.Reflection.BindingFlags]'Instance, Nonpublic' $context = $ExecutionContext.GetType().GetField('_context', $flags).GetValue($ExecutionContext) [System.Management.Automation.Cmdlet].GetProperty('Context', $flags).SetValue($cmdlet, $context, $null) foreach ($keyValuePair in $Parameters.GetEnumerator()) { $property = $cmdlet.GetType().GetProperty($keyValuePair.Key) if ($null -eq $property -or -not $property.CanWrite) { continue } $isParameter = [bool]($property.GetCustomAttributes([System.Management.Automation.ParameterAttribute], $true)) if (-not $isParameter) { continue } $property.SetValue($cmdlet, $keyValuePair.Value, $null) } try { # This unary comma is important in some cases. On Windows 7 systems, the ActiveDirectory module cmdlets # return objects from this method which implement IEnumerable for some reason, and even cause PowerShell # to throw an exception when it tries to cast the object to that interface. # We avoid that problem by wrapping the result of GetDynamicParameters() in a one-element array with the # unary comma. PowerShell enumerates that array instead of trying to enumerate the goofy object, and # everyone's happy. # Love the comma. Don't delete it. We don't have a test for this yet, unless we can get the AD module # on a Server 2008 R2 build server, or until we write some C# code to reproduce its goofy behavior. ,$cmdlet.GetDynamicParameters() } catch [System.NotImplementedException] { # Some cmdlets implement IDynamicParameters but then throw a NotImplementedException. I have no idea why. Ignore them. } } function Get-DynamicParametersForMockedFunction { [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [string] $FunctionName, [string] $ModuleName, [System.Collections.IDictionary] $Parameters, [object] $Cmdlet ) $mock = $mockTable["$ModuleName||$FunctionName"] if (-not $mock) { throw "Internal error detected: Mock for '$FunctionName' in module '$ModuleName' was called, but does not exist in the mock table." } if ($mock.DynamicParamScriptBlock) { $splat = @{ 'P S Cmdlet' = $Cmdlet } return & $mock.DynamicParamScriptBlock @Parameters @splat } } |