Functions/PesterState.ps1

function New-PesterState
{
    param (
        [String[]]$TagFilter,
        [String[]]$ExcludeTagFilter,
        [String[]]$TestNameFilter,
        [System.Management.Automation.SessionState]$SessionState,
        [Switch]$Strict,
        [Pester.OutputTypes]$Show = 'All',
        [object]$PesterOption
    )

    if ($null -eq $SessionState) { $SessionState = $ExecutionContext.SessionState }

    if ($null -eq $PesterOption)
    {
        $PesterOption = New-PesterOption
    }
    elseif ($PesterOption -is [System.Collections.IDictionary])
    {
        try
        {
            $PesterOption = New-PesterOption @PesterOption
        }
        catch
        {
            throw
        }
    }

    & $SafeCommands['New-Module'] -Name Pester -AsCustomObject -ArgumentList $TagFilter, $ExcludeTagFilter, $TestNameFilter, $SessionState, $Strict, $Show, $PesterOption -ScriptBlock {
        param (
            [String[]]$_tagFilter,
            [String[]]$_excludeTagFilter,
            [String[]]$_testNameFilter,
            [System.Management.Automation.SessionState]$_sessionState,
            [Switch]$Strict,
            [Pester.OutputTypes]$Show,
            [object]$PesterOption
        )

        #public read-only
        $TagFilter = $_tagFilter
        $ExcludeTagFilter = $_excludeTagFilter
        $TestNameFilter = $_testNameFilter

        $script:SessionState = $_sessionState
        $script:Stopwatch = [System.Diagnostics.Stopwatch]::StartNew()
        $script:MostRecentTimestamp = 0
        $script:CommandCoverage = @()
        $script:Strict = $Strict
        $script:Show = $Show
        $script:InTest = $false

        $script:TestResult = @()

        $script:TotalCount = 0
        $script:Time = [timespan]0
        $script:PassedCount = 0
        $script:FailedCount = 0
        $script:SkippedCount = 0
        $script:PendingCount = 0
        $script:InconclusiveCount = 0

        $script:IncludeVSCodeMarker = $PesterOption.IncludeVSCodeMarker
        $script:TestSuiteName       = $PesterOption.TestSuiteName

        $script:SafeCommands = @{}

        $script:SafeCommands['New-Object']          = & (Pester\SafeGetCommand) -Name New-Object          -Module Microsoft.PowerShell.Utility -CommandType Cmdlet
        $script:SafeCommands['Select-Object']       = & (Pester\SafeGetCommand) -Name Select-Object       -Module Microsoft.PowerShell.Utility -CommandType Cmdlet
        $script:SafeCommands['Export-ModuleMember'] = & (Pester\SafeGetCommand) -Name Export-ModuleMember -Module Microsoft.PowerShell.Core    -CommandType Cmdlet
        $script:SafeCommands['Add-Member']          = & (Pester\SafeGetCommand) -Name Add-Member          -Module Microsoft.PowerShell.Utility -CommandType Cmdlet

        function New-TestGroup([string] $Name, [string] $Hint)
        {
            & $SafeCommands['New-Object'] psobject -Property @{
                Name              = $Name
                Type              = 'TestGroup'
                Hint              = $Hint
                Actions           = [System.Collections.ArrayList]@()
                BeforeEach        = & $SafeCommands['New-Object'] System.Collections.Generic.List[scriptblock]
                AfterEach         = & $SafeCommands['New-Object'] System.Collections.Generic.List[scriptblock]
                BeforeAll         = & $SafeCommands['New-Object'] System.Collections.Generic.List[scriptblock]
                AfterAll          = & $SafeCommands['New-Object'] System.Collections.Generic.List[scriptblock]
                TotalCount        = 0
                Time              = [timespan]0
                PassedCount       = 0
                FailedCount       = 0
                SkippedCount      = 0
                PendingCount      = 0
                InconclusiveCount = 0
            }
        }

        $script:TestActions = New-TestGroup -Name Pester -Hint Root
        $script:TestGroupStack = & $SafeCommands['New-Object'] System.Collections.Stack
        $script:TestGroupStack.Push($script:TestActions)

        function EnterTestGroup([string] $Name, [string] $Hint)
        {
            $newGroup = New-TestGroup @PSBoundParameters
            $null = $script:TestGroupStack.Peek().Actions.Add($newGroup)
            $script:TestGroupStack.Push($newGroup)
        }

        function LeaveTestGroup([string] $Name, [string] $Hint)
        {
            $currentGroup = $script:TestGroupStack.Pop()

            if ($currentGroup.Name -ne $Name -or $currentGroup.Hint -ne $Hint)
            {
                throw "TestGroups stack corrupted: Expected name/hint of '$Name','$Hint'. Found '$($currentGroup.Name)', '$($currentGroup.Hint)'."
            }
        }

        function AddTestResult
        {
            param (
                [string]$Name,
                [ValidateSet("Failed","Passed","Skipped","Pending","Inconclusive")]
                [string]$Result,
                [Nullable[TimeSpan]]$Time,
                [string]$FailureMessage,
                [string]$StackTrace,
                [string] $ParameterizedSuiteName,
                [System.Collections.IDictionary] $Parameters,
                [System.Management.Automation.ErrorRecord] $ErrorRecord
            )

            # defining this function in here, because otherwise it is not available
            function New-ErrorRecord ([string] $Message, [string] $ErrorId, [string] $File, [string] $Line, [string] $LineText) {
                $exception = & $SafeCommands['New-Object'] Exception $Message
                $errorCategory = [Management.Automation.ErrorCategory]::InvalidResult
                # we use ErrorRecord.TargetObject to pass structured information about the error to a reporting system.
                $targetObject = @{Message = $Message; File = $File; Line = $Line; LineText = $LineText}
                $errorRecord = & $SafeCommands['New-Object'] Management.Automation.ErrorRecord $exception, $ErrorID, $errorCategory, $targetObject
                return $errorRecord
            }

            $previousTime = $script:MostRecentTimestamp
            $script:MostRecentTimestamp = $script:Stopwatch.Elapsed

            if ($null -eq $Time)
            {
                $Time = $script:MostRecentTimestamp - $previousTime
            }

            if (-not $script:Strict)
            {
                $Passed = "Passed","Skipped","Pending" -contains $Result
            }
            else
            {
                $Passed = $Result -eq "Passed"
                if (($Result -eq "Skipped") -or ($Result -eq "Pending"))
                {
                    $FailureMessage = "The test failed because the test was executed in Strict mode and the result '$result' was translated to Failed."
                    $ErrorRecord = New-ErrorRecord -ErrorId 'PesterTestInconclusive' -Message $FailureMessage
                    $Result = "Failed"
                }

            }

            $script:TotalCount++
            $script:Time += $Time

            switch ($Result)
            {
                Passed  { $script:PassedCount++; break; }
                Failed  { $script:FailedCount++; break; }
                Skipped { $script:SkippedCount++; break; }
                Pending { $script:PendingCount++; break; }
                Inconclusive { $script:InconclusiveCount++; break; }
            }

            $resultRecord = & $SafeCommands['New-Object'] -TypeName PsObject -Property @{
                Name                   = $Name
                Type                   = 'TestCase'
                Passed                 = $Passed
                Result                 = $Result
                Time                   = $Time
                FailureMessage         = $FailureMessage
                StackTrace             = $StackTrace
                ErrorRecord            = $ErrorRecord
                ParameterizedSuiteName = $ParameterizedSuiteName
                Parameters             = $Parameters
                Show                   = $script:Show
            }

            $null = $script:TestGroupStack.Peek().Actions.Add($resultRecord)

            # Attempting some degree of backward compatibility for the TestResult collection for now; deprecated and will be removed in the future
            $describe = ''
            $contexts = [System.Collections.ArrayList]@()

            # make a copy of the stack and reverse it
            $reversedStack = $script:TestGroupStack.ToArray()
            [array]::Reverse($reversedStack)

            foreach ($group in $reversedStack)
            {
                if ($group.Hint -eq 'Root' -or $group.Hint -eq 'Script') { continue }
                if ($describe -eq '')
                {
                    $describe = $group.Name
                }
                else
                {
                    $null = $contexts.Add($group.Name)
                }
            }

            $context = $contexts -join '\'

            $script:TestResult += & $SafeCommands['New-Object'] psobject -Property @{
                Describe               = $describe
                Context                = $context
                Name                   = $Name
                Passed                 = $Passed
                Result                 = $Result
                Time                   = $Time
                FailureMessage         = $FailureMessage
                StackTrace             = $StackTrace
                ErrorRecord            = $ErrorRecord
                ParameterizedSuiteName = $ParameterizedSuiteName
                Parameters             = $Parameters
                Show                  = $script:Show
            }
        }

        function AddSetupOrTeardownBlock([scriptblock] $ScriptBlock, [string] $CommandName)
        {
            $currentGroup = $script:TestGroupStack.Peek()

            $isSetupCommand = IsSetupCommand -CommandName $CommandName
            $isGroupCommand = IsTestGroupCommand -CommandName $CommandName

            if ($isSetupCommand)
            {
                if ($isGroupCommand)
                {
                    $currentGroup.BeforeAll.Add($ScriptBlock)
                }
                else
                {
                    $currentGroup.BeforeEach.Add($ScriptBlock)
                }
            }
            else
            {
                if ($isGroupCommand)
                {
                    $currentGroup.AfterAll.Add($ScriptBlock)
                }
                else
                {
                    $currentGroup.AfterEach.Add($ScriptBlock)
                }
            }
        }

        function IsSetupCommand
        {
            param ([string] $CommandName)
            return $CommandName -eq 'BeforeEach' -or $CommandName -eq 'BeforeAll'
        }

        function IsTestGroupCommand
        {
            param ([string] $CommandName)
            return $CommandName -eq 'BeforeAll' -or $CommandName -eq 'AfterAll'
        }

        function GetTestCaseSetupBlocks
        {
            $blocks = @(
                foreach ($group in $this.TestGroups)
                {
                    $group.BeforeEach
                }
            )

            return $blocks
        }

        function GetTestCaseTeardownBlocks
        {
            $groups = @($this.TestGroups)
            [Array]::Reverse($groups)

            $blocks = @(
                foreach ($group in $groups)
                {
                    $group.AfterEach
                }
            )

            return $blocks
        }

        function GetCurrentTestGroupSetupBlocks
        {
            return $script:TestGroupStack.Peek().BeforeAll
        }

        function GetCurrentTestGroupTeardownBlocks
        {
            return $script:TestGroupStack.Peek().AfterAll
        }

        function EnterTest
        {
            if ($script:InTest)
            {
                throw 'You are already in a test case.'
            }

            $script:InTest = $true
        }

        function LeaveTest
        {
            $script:InTest = $false
        }

        $ExportedVariables = "TagFilter",
        "ExcludeTagFilter",
        "TestNameFilter",
        "TestResult",
        "SessionState",
        "CommandCoverage",
        "Strict",
        "Show",
        "Time",
        "TotalCount",
        "PassedCount",
        "FailedCount",
        "SkippedCount",
        "PendingCount",
        "InconclusiveCount",
        "IncludeVSCodeMarker",
        "TestActions",
        "TestGroupStack",
        "TestSuiteName",
        "InTest"

        $ExportedFunctions = "EnterTestGroup",
                             "LeaveTestGroup",
                             "AddTestResult",
                             "AddSetupOrTeardownBlock",
                             "GetTestCaseSetupBlocks",
                             "GetTestCaseTeardownBlocks",
                             "GetCurrentTestGroupSetupBlocks",
                             "GetCurrentTestGroupTeardownBlocks",
                             "EnterTest",
                             "LeaveTest"

        & $SafeCommands['Export-ModuleMember'] -Variable $ExportedVariables -function $ExportedFunctions
    }  |
    & $SafeCommands['Add-Member'] -PassThru -MemberType ScriptProperty -Name CurrentTestGroup -Value {
        $this.TestGroupStack.Peek()
    } |
    & $SafeCommands['Add-Member'] -PassThru -MemberType ScriptProperty -Name TestGroups -Value {
        $array = $this.TestGroupStack.ToArray()
        [Array]::Reverse($array)
        return $array
    } |
    & $SafeCommands['Add-Member'] -PassThru -MemberType ScriptProperty -Name IndentLevel -Value {
        # We ignore the root node of the stack here, and don't start indenting until after the Script nodes inside the root
        return [Math]::Max(0, $this.TestGroupStack.Count - 2)
    }
}