Pester.psm1

# Pester
# Version: $version$
# Changeset: $sha$

if ($PSVersionTable.PSVersion.Major -ge 3)
{
    $script:IgnoreErrorPreference = 'Ignore'
    $outNullModule = 'Microsoft.PowerShell.Core'
    $outHostModule = 'Microsoft.PowerShell.Core'
}
else
{
    $script:IgnoreErrorPreference = 'SilentlyContinue'
    $outNullModule = 'Microsoft.PowerShell.Utility'
    $outHostModule = $null
}

# Tried using $ExecutionState.InvokeCommand.GetCmdlet() here, but it does not trigger module auto-loading the way
# Get-Command does.  Since this is at import time, before any mocks have been defined, that's probably acceptable.
# If someone monkeys with Get-Command before they import Pester, they may break something.

# The -All parameter is required when calling Get-Command to ensure that PowerShell can find the command it is
# looking for. Otherwise, if you have modules loaded that define proxy cmdlets or that have cmdlets with the same
# name as the safe cmdlets, Get-Command will return null.
$safeCommandLookupParameters = @{
    CommandType = [System.Management.Automation.CommandTypes]::Cmdlet
    ErrorAction = [System.Management.Automation.ActionPreference]::Stop
}

if ($PSVersionTable.PSVersion.Major -gt 2)
{
    $safeCommandLookupParameters['All'] = $true
}

$script:SafeCommands = @{
    'Add-Member'          = Get-Command -Name Add-Member          -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Add-Type'            = Get-Command -Name Add-Type            -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Compare-Object'      = Get-Command -Name Compare-Object      -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Export-ModuleMember' = Get-Command -Name Export-ModuleMember -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'ForEach-Object'      = Get-Command -Name ForEach-Object      -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'Format-Table'        = Get-Command -Name Format-Table        -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Get-ChildItem'       = Get-Command -Name Get-ChildItem       -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Get-Command'         = Get-Command -Name Get-Command         -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'Get-Content'         = Get-Command -Name Get-Content         -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Get-Date'            = Get-Command -Name Get-Date            -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Get-Item'            = Get-Command -Name Get-Item            -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Get-Location'        = Get-Command -Name Get-Location        -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Get-Member'          = Get-Command -Name Get-Member          -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Get-Module'          = Get-Command -Name Get-Module          -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'Get-PSDrive'         = Get-Command -Name Get-PSDrive         -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Get-Variable'        = Get-Command -Name Get-Variable        -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Group-Object'        = Get-Command -Name Group-Object        -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Join-Path'           = Get-Command -Name Join-Path           -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Measure-Object'      = Get-Command -Name Measure-Object      -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'New-Item'            = Get-Command -Name New-Item            -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'New-Module'          = Get-Command -Name New-Module          -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'New-Object'          = Get-Command -Name New-Object          -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'New-PSDrive'         = Get-Command -Name New-PSDrive         -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'New-Variable'        = Get-Command -Name New-Variable        -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Out-Host'            = Get-Command -Name Out-Host            -Module $outHostModule                  @safeCommandLookupParameters
    'Out-File'            = Get-Command -Name Out-File            -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Out-Null'            = Get-Command -Name Out-Null            -Module $outNullModule                  @safeCommandLookupParameters
    'Out-String'          = Get-Command -Name Out-String          -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Pop-Location'        = Get-Command -Name Pop-Location        -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Push-Location'       = Get-Command -Name Push-Location       -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Remove-Item'         = Get-Command -Name Remove-Item         -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Remove-PSBreakpoint' = Get-Command -Name Remove-PSBreakpoint -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Remove-PSDrive'      = Get-Command -Name Remove-PSDrive      -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Remove-Variable'     = Get-Command -Name Remove-Variable     -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Resolve-Path'        = Get-Command -Name Resolve-Path        -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Select-Object'       = Get-Command -Name Select-Object       -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Set-Content'         = Get-Command -Name Set-Content         -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Set-PSBreakpoint'    = Get-Command -Name Set-PSBreakpoint    -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Set-StrictMode'      = Get-Command -Name Set-StrictMode      -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'Set-Variable'        = Get-Command -Name Set-Variable        -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Sort-Object'         = Get-Command -Name Sort-Object         -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Split-Path'          = Get-Command -Name Split-Path          -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Start-Sleep'         = Get-Command -Name Start-Sleep         -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Test-Path'           = Get-Command -Name Test-Path           -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
    'Where-Object'        = Get-Command -Name Where-Object        -Module Microsoft.PowerShell.Core       @safeCommandLookupParameters
    'Write-Error'         = Get-Command -Name Write-Error         -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Write-Host'          = Get-Command -Name Write-Host          -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Write-Progress'      = Get-Command -Name Write-Progress      -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Write-Verbose'       = Get-Command -Name Write-Verbose       -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
    'Write-Warning'       = Get-Command -Name Write-Warning       -Module Microsoft.PowerShell.Utility    @safeCommandLookupParameters
}

# Not all platforms have Get-WmiObject (Nano)
# Get-CimInstance is prefered, but we can use Get-WmiObject if it exists
# Moreover, it shouldn't really be fatal if neither of those cmdlets
# exist
if ( Get-Command -ea SilentlyContinue Get-CimInstance )
{
    $script:SafeCommands['Get-CimInstance'] = Get-Command -Name Get-CimInstance -Module CimCmdlets @safeCommandLookupParameters
}
elseif ( Get-command -ea SilentlyContinue Get-WmiObject )
{
    $script:SafeCommands['Get-WmiObject']   = Get-Command -Name Get-WmiObject   -Module Microsoft.PowerShell.Management @safeCommandLookupParameters
}
else
{
    Write-Warning "OS Information retrieval is not possible, reports will contain only partial system data"
}

# little sanity check to make sure we don't blow up a system with a typo up there
# (not that I've EVER done that by, for example, mapping New-Item to Remove-Item...)

foreach ($keyValuePair in $script:SafeCommands.GetEnumerator())
{
    if ($keyValuePair.Key -ne $keyValuePair.Value.Name)
    {
        throw "SafeCommands entry for $($keyValuePair.Key) does not hold a reference to the proper command."
    }
}

$script:AssertionOperators = & $SafeCommands['New-Object'] 'Collections.Generic.Dictionary[string,object]'([StringComparer]::InvariantCultureIgnoreCase)
$script:AssertionAliases = & $SafeCommands['New-Object'] 'Collections.Generic.Dictionary[string,object]'([StringComparer]::InvariantCultureIgnoreCase)
$script:AssertionDynamicParams = & $SafeCommands['New-Object'] System.Management.Automation.RuntimeDefinedParameterDictionary

function Test-NullOrWhiteSpace {
    param ([string]$String)

    $String -match "^\s*$"
}

function Assert-ValidAssertionName
{
    param([string]$Name)
    if ($Name -notmatch '^\S+$')
    {
        throw "Assertion name '$name' is invalid, assertion name must be a single word."
    }
}

function Assert-ValidAssertionAlias
{
    param([string]$Alias)
    if ($Alias -notmatch '^\S+$')
    {
        throw "Assertion alias '$string' is invalid, assertion alias must be a single word."
    }
}

function Add-AssertionOperator
{
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [string] $Name,

        [Parameter(Mandatory = $true)]
        [scriptblock] $Test,

        [ValidateNotNullOrEmpty()]
        [string[]] $Alias,

        [switch] $SupportsArrayInput
    )

    $namesToCheck = @(
        $Name
        $Alias
    )

    Assert-AssertionOperatorNameIsUnique -Name $namesToCheck

    $entry = New-Object psobject -Property @{
        Test                       = $Test
        SupportsArrayInput         = [bool]$SupportsArrayInput
        Name                       = $Name
        Alias                      = $Alias
    }

    $script:AssertionOperators[$Name] = $entry

    foreach ($string in $Alias | where { -not (Test-NullOrWhiteSpace $_)})
    {
        Assert-ValidAssertionAlias -Alias $string
        $script:AssertionAliases[$string] = $Name
    }

    Add-AssertionDynamicParameterSet -AssertionEntry $entry
}

function Assert-AssertionOperatorNameIsUnique
{
    param (
        [string[]] $Name
    )

    foreach ($string in $name | where { -not (Test-NullOrWhiteSpace $_)})
    {
        Assert-ValidAssertionName -Name $string

        if ($script:AssertionOperators.ContainsKey($string))
        {
            throw "Assertion operator name '$string' has been added multiple times."
        }

        if ($script:AssertionAliases.ContainsKey($string))
        {
            throw "Assertion operator name '$string' already exists as an alias for operator '$($script:AssertionAliases[$key])'"
        }
    }
}

function Add-AssertionDynamicParameterSet
{
    param (
        [object] $AssertionEntry
    )

    ${function:__AssertionTest__} = $AssertionEntry.Test
    $commandInfo = Get-Command __AssertionTest__ -CommandType Function
    $metadata = [System.Management.Automation.CommandMetadata]$commandInfo

    $attribute = New-Object Management.Automation.ParameterAttribute
    $attribute.ParameterSetName = $AssertionEntry.Name
    $attribute.Mandatory = $true

    $attributeCollection = New-Object Collections.ObjectModel.Collection[Attribute]
    $null = $attributeCollection.Add($attribute)
    if (-not (Test-NullOrWhiteSpace $AssertionEntry.Alias))
    {
        Assert-ValidAssertionAlias -Alias $AssertionEntry.Alias
        $attribute = New-Object System.Management.Automation.AliasAttribute($AssertionEntry.Alias)
        $attributeCollection.Add($attribute)
    }

    $dynamic = New-Object System.Management.Automation.RuntimeDefinedParameter($AssertionEntry.Name, [switch], $attributeCollection)
    $null = $script:AssertionDynamicParams.Add($AssertionEntry.Name, $dynamic)

    if ($script:AssertionDynamicParams.ContainsKey('Not'))
    {
        $dynamic = $script:AssertionDynamicParams['Not']
    }
    else
    {
        $dynamic = New-Object System.Management.Automation.RuntimeDefinedParameter('Not', [switch], (New-Object System.Collections.ObjectModel.Collection[Attribute]))
        $null = $script:AssertionDynamicParams.Add('Not', $dynamic)
    }

    $attribute = New-Object System.Management.Automation.ParameterAttribute
    $attribute.ParameterSetName = $AssertionEntry.Name
    $attribute.Mandatory = $false
    $null = $dynamic.Attributes.Add($attribute)

    $i = 1
    foreach ($parameter in $metadata.Parameters.Values)
    {
        if ($parameter.Name -eq 'ActualValue' -or $parameter.Name -eq 'Not' -or $parameter.Name -eq 'Negate') { continue }

        if ($script:AssertionOperators.ContainsKey($parameter.Name) -or $script:AssertionAliases.ContainsKey($parameter.Name))
        {
            throw "Test block for assertion operator $($AssertionEntry.Name) contains a parameter named $($parameter.Name), which conflicts with another assertion operator's name or alias."
        }

        foreach ($alias in $parameter.Aliases)
        {
            if ($script:AssertionOperators.ContainsKey($alias) -or $script:AssertionAliases.ContainsKey($alias))
            {
                throw "Test block for assertion operator $($AssertionEntry.Name) contains a parameter named $($parameter.Name) with alias $alias, which conflicts with another assertion operator's name or alias."
            }
        }

        if ($script:AssertionDynamicParams.ContainsKey($parameter.Name))
        {
            $dynamic = $script:AssertionDynamicParams[$parameter.Name]
        }
        else
           {
            # We deliberatey use a type of [object] here to avoid conflicts between different assertion operators that may use the same parameter name.
            # We also don't bother to try to copy transformation / validation attributes here for the same reason.
            # Because we'll be passing these parameters on to the actual test function later, any errors will come out at that time.

            $dynamic = New-Object System.Management.Automation.RuntimeDefinedParameter($parameter.Name, [object], (New-Object System.Collections.ObjectModel.Collection[Attribute]))
            $null = $script:AssertionDynamicParams.Add($parameter.Name, $dynamic)
        }

        $attribute = New-Object Management.Automation.ParameterAttribute
        $attribute.ParameterSetName = $AssertionEntry.Name
        $attribute.Mandatory = $false
        $attribute.Position = ($i++)

        $null = $dynamic.Attributes.Add($attribute)
    }
}

function Get-AssertionOperatorEntry([string] $Name)
{
    return $script:AssertionOperators[$Name]
}

function Get-AssertionDynamicParams
{
    return $script:AssertionDynamicParams
}

$Script:PesterRoot = & $SafeCommands['Split-Path'] -Path $MyInvocation.MyCommand.Path
$moduleRoot = & $script:SafeCommands['Split-Path'] -Path $MyInvocation.MyCommand.Path

"$PesterRoot\Functions\*.ps1", "$PesterRoot\Functions\Assertions\*.ps1" |
& $script:SafeCommands['Resolve-Path'] |
& $script:SafeCommands['Where-Object'] { -not ($_.ProviderPath.ToLower().Contains(".tests.")) } |
& $script:SafeCommands['ForEach-Object'] { . $_.ProviderPath }

Add-Type -TypeDefinition @"
using System;

namespace Pester
{
    [Flags]
    public enum OutputTypes
    {
        None = 0,
        Default = 1,
        Passed = 2,
        Failed = 4,
        Pending = 8,
        Skipped = 16,
        Inconclusive = 32,
        Describe = 64,
        Context = 128,
        Summary = 256,
        Header = 512,
        All = Default | Passed | Failed | Pending | Skipped | Inconclusive | Describe | Context | Summary | Header,
        Fails = Default | Failed | Pending | Skipped | Inconclusive | Describe | Context | Summary | Header
    }
}
"@

function Has-Flag  {
     param
     (
         [Parameter(Mandatory = $true)]
         [Pester.OutputTypes]
         $Setting,
         [Parameter(Mandatory = $true, ValueFromPipeline=$true)]
         [Pester.OutputTypes]
         $Value
     )

  0 -ne ($Setting -band $Value)
}

function Invoke-Pester {
<#
.SYNOPSIS
Runs Pester tests

.DESCRIPTION
The Invoke-Pester function runs Pester tests, including *.Tests.ps1 files and
Pester tests in PowerShell scripts.

You can run scripts that include Pester tests just as you would any other
Windows PowerShell script, including typing the full path at the command line
and running in a script editing program. Typically, you use Invoke-Pester to run
all Pester tests in a directory, or to use its many helpful parameters,
including parameters that generate custom objects or XML files.

By default, Invoke-Pester runs all *.Tests.ps1 files in the current directory
and all subdirectories recursively. You can use its parameters to select tests
by file name, test name, or tag.

To run Pester tests in scripts that take parameter values, use the Script
parameter with a hash table value.

Also, by default, Pester tests write test results to the console host, much like
Write-Host does, but you can use the Quiet parameter to suppress the host
messages, use the PassThru parameter to generate a custom object
(PSCustomObject) that contains the test results, use the OutputXml and
OutputFormat parameters to write the test results to an XML file, and use the
EnableExit parameter to return an exit code that contains the number of failed
tests.

You can also use the Strict parameter to fail all pending and skipped tests.
This feature is ideal for build systems and other processes that require success
on every test.

To help with test design, Invoke-Pester includes a CodeCoverage parameter that
lists commands, functions, and lines of code that did not run during test
execution and returns the code that ran as a percentage of all tested code.

Invoke-Pester, and the Pester module that exports it, are products of an
open-source project hosted on GitHub. To view, comment, or contribute to the
repository, see https://github.com/Pester.

.PARAMETER Script
Specifies the test files that Pester runs. You can also use the Script parameter
to pass parameter names and values to a script that contains Pester tests. The
value of the Script parameter can be a string, a hash table, or a collection
of hash tables and strings. Wildcard characters are supported.

The Script parameter is optional. If you omit it, Invoke-Pester runs all
*.Tests.ps1 files in the local directory and its subdirectories recursively.

To run tests in other files, such as .ps1 files, enter the path and file name of
the file. (The file name is required. Name patterns that end in "*.ps1" run only
*.Tests.ps1 files.)

To run a Pester test with parameter names and/or values, use a hash table as the
value of the script parameter. The keys in the hash table are:

-- Path [string] (required): Specifies a test to run. The value is a path\file
   name or name pattern. Wildcards are permitted. All hash tables in a Script
   parameter value must have a Path key.

-- Parameters [hashtable]: Runs the script with the specified parameters. The
   value is a nested hash table with parameter name and value pairs, such as
   @{UserName = 'User01'; Id = '28'}.

-- Arguments [array]: An array or comma-separated list of parameter values
   without names, such as 'User01', 28. Use this key to pass values to positional
   parameters.


.PARAMETER TestName
Runs only tests in Describe blocks that have the specified name or name pattern.
Wildcard characters are supported.

If you specify multiple TestName values, Invoke-Pester runs tests that have any
of the values in the Describe name (it ORs the TestName values).

.PARAMETER EnableExit
Will cause Invoke-Pester to exit with a exit code equal to the number of failed
tests once all tests have been run. Use this to "fail" a build when any tests fail.

.PARAMETER OutputFile
The path where Invoke-Pester will save formatted test results log file.

The path must include the location and name of the folder and file name with
the xml extension.

If this path is not provided, no log will be generated.

.PARAMETER OutputFormat
The format of output. Two formats of output are supported: NUnitXML and
LegacyNUnitXML.

.PARAMETER Tag
Runs only tests in Describe blocks with the specified Tag parameter values.
Wildcard characters and Tag values that include spaces or whitespace characters
are not supported.

When you specify multiple Tag values, Invoke-Pester runs tests that have any
of the listed tags (it ORs the tags). However, when you specify TestName
and Tag values, Invoke-Pester runs only describe blocks that have one of the
specified TestName values and one of the specified Tag values.

If you use both Tag and ExcludeTag, ExcludeTag takes precedence.

.PARAMETER ExcludeTag
Omits tests in Describe blocks with the specified Tag parameter values. Wildcard
characters and Tag values that include spaces or whitespace characters are not
supported.

When you specify multiple ExcludeTag values, Invoke-Pester omits tests that have
any of the listed tags (it ORs the tags). However, when you specify TestName
and ExcludeTag values, Invoke-Pester omits only describe blocks that have one
of the specified TestName values and one of the specified Tag values.

If you use both Tag and ExcludeTag, ExcludeTag takes precedence

.PARAMETER PassThru
Returns a custom object (PSCustomObject) that contains the test results.

By default, Invoke-Pester writes to the host program, not to the output stream (stdout).
If you try to save the result in a variable, the variable is empty unless you
use the PassThru parameter.

To suppress the host output, use the Quiet parameter.

.PARAMETER CodeCoverage
Adds a code coverage report to the Pester tests. Takes strings or hash table values.

A code coverage report lists the lines of code that did and did not run during
a Pester test. This report does not tell whether code was tested; only whether
the code ran during the test.

By default, the code coverage report is written to the host program
(like Write-Host). When you use the PassThru parameter, the custom object
that Invoke-Pester returns has an additional CodeCoverage property that contains
a custom object with detailed results of the code coverage test, including lines
hit, lines missed, and helpful statistics.

However, NUnitXML and LegacyNUnitXML output (OutputXML, OutputFormat) do not include
any code coverage information, because it's not supported by the schema.

Enter the path to the files of code under test (not the test file).
Wildcard characters are supported. If you omit the path, the default is local
directory, not the directory specified by the Script parameter.

To run a code coverage test only on selected functions or lines in a script,
enter a hash table value with the following keys:

-- Path (P)(mandatory) <string>. Enter one path to the files. Wildcard characters
   are supported, but only one string is permitted.

One of the following: Function or StartLine/EndLine

-- Function (F) <string>: Enter the function name. Wildcard characters are
   supported, but only one string is permitted.

-or-

-- StartLine (S): Performs code coverage analysis beginning with the specified
   line. Default is line 1.
-- EndLine (E): Performs code coverage analysis ending with the specified line.
   Default is the last line of the script.

.PARAMETER CodeCoverageOutputFile
The path where Invoke-Pester will save formatted code coverage results file in JaCoCo format.

The path must include the location and name of the folder and file name with
the xml extension.

If this path is not provided, no xml file will be generated.


.PARAMETER Strict
Makes Pending and Skipped tests to Failed tests. Useful for continuous
integration where you need to make sure all tests passed.

.PARAMETER Quiet
The parameter Quiet is deprecated since Pester v. 4.0 and will be deleted
in the next major version of Pester. Please use the parameter Show
with value 'None' instead.

The parameter Quiet suppresses the output that Pester writes to the host program,
including the result summary and CodeCoverage output.

This parameter does not affect the PassThru custom object or the XML output that
is written when you use the Output parameters.

.PARAMETER Show
Customizes the output Pester writes to the screen. Available options are None, Default,
Passed, Failed, Pending, Skipped, Inconclusive, Describe, Context, Summary, Header, All, Fails.

The options can be combined to define presets.
Common use cases are:

None - to write no output to the screen.
All - to write all available information (this is default option).
Fails - to write everything except Passed (but including Describes etc.).

A common setting is also Failed, Summary, to write only failed tests and test summary.

This parameter does not affect the PassThru custom object or the XML output that
is written when you use the Output parameters.

.PARAMETER PesterOption
Sets advanced options for the test execution. Enter a PesterOption object,
such as one that you create by using the New-PesterOption cmdlet, or a hash table
in which the keys are option names and the values are option values.
For more information on the options available, see the help for New-PesterOption.

.Example
Invoke-Pester

This command runs all *.Tests.ps1 files in the current directory and its subdirectories.

.Example
Invoke-Pester -Script .\Util*

This commands runs all *.Tests.ps1 files in subdirectories with names that begin
with 'Util' and their subdirectories.

.Example
Invoke-Pester -Script D:\MyModule, @{ Path = '.\Tests\Utility\ModuleUnit.Tests.ps1'; Parameters = @{ Name = 'User01' }; Arguments = srvNano16  }

This command runs all *.Tests.ps1 files in D:\MyModule and its subdirectories.
It also runs the tests in the ModuleUnit.Tests.ps1 file using the following
parameters: .\Tests\Utility\ModuleUnit.Tests.ps1 srvNano16 -Name User01

.Example
Invoke-Pester -TestName "Add Numbers"

This command runs only the tests in the Describe block named "Add Numbers".

.EXAMPLE
$results = Invoke-Pester -Script D:\MyModule -PassThru -Show None
$failed = $results.TestResult | where Result -eq 'Failed'

$failed.Name
cannot find help for parameter: Force : in Compress-Archive
help for Force parameter in Compress-Archive has wrong Mandatory value
help for Compress-Archive has wrong parameter type for Force
help for Update parameter in Compress-Archive has wrong Mandatory value
help for DestinationPath parameter in Expand-Archive has wrong Mandatory value

$failed[0]
Describe               : Test help for Compress-Archive in Microsoft.PowerShell.Archive (1.0.0.0)
Context                : Test parameter help for Compress-Archive
Name                   : cannot find help for parameter: Force : in Compress-Archive
Result                 : Failed
Passed                 : False
Time                   : 00:00:00.0193083
FailureMessage         : Expected: value to not be empty
StackTrace             : at line: 279 in C:\GitHub\PesterTdd\Module.Help.Tests.ps1
                         279:                     $parameterHelp.Description.Text | Should Not BeNullOrEmpty
ErrorRecord            : Expected: value to not be empty
ParameterizedSuiteName :
Parameters             : {}

This examples uses the PassThru parameter to return a custom object with the
Pester test results. By default, Invoke-Pester writes to the host program, but not
to the output stream. It also uses the Quiet parameter to suppress the host output.

The first command runs Invoke-Pester with the PassThru and Quiet parameters and
saves the PassThru output in the $results variable.

The second command gets only failing results and saves them in the $failed variable.

The third command gets the names of the failing results. The result name is the
name of the It block that contains the test.

The fourth command uses an array index to get the first failing result. The
property values describe the test, the expected result, the actual result, and
useful values, including a stack tace.

.Example
Invoke-Pester -EnableExit -OutputFile ".\artifacts\TestResults.xml" -OutputFormat NUnitXml

This command runs all tests in the current directory and its subdirectories. It
writes the results to the TestResults.xml file using the NUnitXml schema. The
test returns an exit code equal to the number of test failures.

 .EXAMPLE
Invoke-Pester -CodeCoverage 'ScriptUnderTest.ps1'

Runs all *.Tests.ps1 scripts in the current directory, and generates a coverage
report for all commands in the "ScriptUnderTest.ps1" file.

.EXAMPLE
Invoke-Pester -CodeCoverage @{ Path = 'ScriptUnderTest.ps1'; Function = 'FunctionUnderTest' }

Runs all *.Tests.ps1 scripts in the current directory, and generates a coverage
report for all commands in the "FunctionUnderTest" function in the "ScriptUnderTest.ps1" file.

 .EXAMPLE
Invoke-Pester -CodeCoverage 'ScriptUnderTest.ps1' -CodeCoverageOutputFile '.\artifacts\TestOutput.xml'

Runs all *.Tests.ps1 scripts in the current directory, and generates a coverage
report for all commands in the "ScriptUnderTest.ps1" file, and writes the coverage report to TestOutput.xml
file using the JaCoCo XML Report DTD.

.EXAMPLE
Invoke-Pester -CodeCoverage @{ Path = 'ScriptUnderTest.ps1'; StartLine = 10; EndLine = 20 }

Runs all *.Tests.ps1 scripts in the current directory, and generates a coverage
report for all commands on lines 10 through 20 in the "ScriptUnderTest.ps1" file.

.EXAMPLE
Invoke-Pester -Script C:\Tests -Tag UnitTest, Newest -ExcludeTag Bug

This command runs *.Tests.ps1 files in C:\Tests and its subdirectories. In those
files, it runs only tests that have UnitTest or Newest tags, unless the test
also has a Bug tag.

.LINK
https://github.com/pester/Pester/wiki/Invoke-Pester
Describe
about_Pester
New-PesterOption

#>
    [CmdletBinding(DefaultParameterSetName = 'Default')]
    param(
        [Parameter(Position=0,Mandatory=0)]
        [Alias('Path', 'relative_path')]
        [object[]]$Script = '.',

        [Parameter(Position=1,Mandatory=0)]
        [Alias("Name")]
        [string[]]$TestName,

        [Parameter(Position=2,Mandatory=0)]
        [switch]$EnableExit,

        [Parameter(Position=4,Mandatory=0)]
        [Alias('Tags')]
        [string[]]$Tag,

        [string[]]$ExcludeTag,

        [switch]$PassThru,

        [object[]] $CodeCoverage = @(),

        [string] $CodeCoverageOutputFile,

        [Switch]$Strict,

        [Parameter(Mandatory = $true, ParameterSetName = 'NewOutputSet')]
        [string] $OutputFile,

        [Parameter(ParameterSetName = 'NewOutputSet')]
        [ValidateSet('NUnitXml')]
        [string] $OutputFormat = 'NUnitXml',

        [Switch]$Quiet,

        [object]$PesterOption,

        [Pester.OutputTypes]$Show = 'All'
    )
    begin {
        # Ensure when running Pester that we're using RSpec strings
        Import-LocalizedData -BindingVariable Script:ReportStrings -BaseDirectory $PesterRoot -FileName RSpec.psd1 -ErrorAction SilentlyContinue

        #Fallback to en-US culture strings
        If ([String]::IsNullOrEmpty($ReportStrings)) {

            Import-LocalizedData -BaseDirectory $PesterRoot -BindingVariable Script:ReportStrings -UICulture 'en-US' -FileName RSpec.psd1 -ErrorAction Stop

        }
    }

    end {
        if ($PSBoundParameters.ContainsKey('Quiet'))
        {
            & $script:SafeCommands['Write-Warning'] 'The -Quiet parameter has been deprecated; please use the new -Show parameter instead. To get no output use -Show None.'
            & $script:SafeCommands['Start-Sleep'] -Seconds 2

            if (!$PSBoundParameters.ContainsKey('Show'))
            {
                $Show = [Pester.OutputTypes]::None
            }
        }

        $script:mockTable = @{}
        $pester = New-PesterState -TestNameFilter $TestName -TagFilter ($Tag -split "\s") -ExcludeTagFilter ($ExcludeTag -split "\s") -SessionState $PSCmdlet.SessionState -Strict:$Strict -Show:$Show -PesterOption $PesterOption

        try
        {
            Enter-CoverageAnalysis -CodeCoverage $CodeCoverage -PesterState $pester
            Write-PesterStart $pester $Script

            $invokeTestScript = {
                param (
                    [Parameter(Position = 0)]
                    [string] $Path,

                    [object[]] $Arguments = @(),
                    [System.Collections.IDictionary] $Parameters = @{}
                )

                & $Path @Parameters @Arguments
            }

            Set-ScriptBlockScope -ScriptBlock $invokeTestScript -SessionState $PSCmdlet.SessionState

            $testScripts = @(ResolveTestScripts $Script)

            foreach ($testScript in $testScripts)
            {
                try
                {
                    $pester.EnterTestGroup($testScript.Path, 'Script')
                    Write-Describe $testScript.Path -CommandUsed Script
                    do
                    {
                        & $invokeTestScript -Path $testScript.Path -Arguments $testScript.Arguments -Parameters $testScript.Parameters
                    } until ($true)
                }
                catch
                {
                    $firstStackTraceLine = $_.ScriptStackTrace -split '\r?\n' | & $script:SafeCommands['Select-Object'] -First 1
                    $pester.AddTestResult("Error occurred in test script '$($testScript.Path)'", "Failed", $null, $_.Exception.Message, $firstStackTraceLine, $null, $null, $_)

                    # This is a hack to ensure that XML output is valid for now.  The test-suite names come from the Describe attribute of the TestResult
                    # objects, and a blank name is invalid NUnit XML.  This will go away when we promote test scripts to have their own test-suite nodes,
                    # planned for v4.0
                    $pester.TestResult[-1].Describe = "Error in $($testScript.Path)"

                    $pester.TestResult[-1] | Write-PesterResult
                }
                finally
                {
                    Exit-MockScope
                    $pester.LeaveTestGroup($testScript.Path, 'Script')
                }
            }

            $pester | Write-PesterReport
            $coverageReport = Get-CoverageReport -PesterState $pester
            Write-CoverageReport -CoverageReport $coverageReport
            if (& $script:SafeCommands['Get-Variable'] -Name CodeCoverageOutputFile -ValueOnly -ErrorAction $script:IgnoreErrorPreference) {
                $jaCoCoReport = Get-JaCoCoReportXml -PesterState $pester -CoverageReport $coverageReport
                $jaCoCoReport | & $SafeCommands['Out-File'] $CodeCoverageOutputFile -Encoding utf8
            }
            Exit-CoverageAnalysis -PesterState $pester
        }
        finally
        {
            Exit-MockScope
        }

        Set-PesterStatistics

        if (& $script:SafeCommands['Get-Variable'] -Name OutputFile -ValueOnly -ErrorAction $script:IgnoreErrorPreference) {
            Export-PesterResults -PesterState $pester -Path $OutputFile -Format $OutputFormat
        }

    if ($PassThru) {
        #remove all runtime properties like current* and Scope
        $properties = @(
            "TagFilter","ExcludeTagFilter","TestNameFilter","TotalCount","PassedCount","FailedCount","SkippedCount","PendingCount",'InconclusiveCount',"Time","TestResult"

                if ($CodeCoverage)
                {
                    @{ Name = 'CodeCoverage'; Expression = { $coverageReport } }
                }
            )

            $pester | & $script:SafeCommands['Select-Object'] -Property $properties
        }

        if ($EnableExit) { Exit-WithCode -FailedCount $pester.FailedCount }
    }
}

function New-PesterOption
{
<#
.SYNOPSIS
   Creates an object that contains advanced options for Invoke-Pester
.PARAMETER IncludeVSCodeMarker
   When this switch is set, an extra line of output will be written to the console for test failures, making it easier
   for VSCode's parser to provide highlighting / tooltips on the line where the error occurred.
.PARAMETER TestSuiteName
   When generating NUnit XML output, this controls the name assigned to the root "test-suite" element.  Defaults to "Pester".
.INPUTS
   None
   You cannot pipe input to this command.
.OUTPUTS
   System.Management.Automation.PSObject
.LINK
   Invoke-Pester
#>

    [CmdletBinding()]
    param (
        [switch] $IncludeVSCodeMarker,

        [ValidateNotNullOrEmpty()]
        [string] $TestSuiteName = 'Pester'
    )

    return & $script:SafeCommands['New-Object'] psobject -Property @{
        IncludeVSCodeMarker = [bool]$IncludeVSCodeMarker
        TestSuiteName       = $TestSuiteName
    }
}

function ResolveTestScripts
{
    param ([object[]] $Path)

    $resolvedScriptInfo = @(
        foreach ($object in $Path)
        {
            if ($object -is [System.Collections.IDictionary])
            {
                $unresolvedPath = Get-DictionaryValueFromFirstKeyFound -Dictionary $object -Key 'Path', 'p'
                $arguments      = @(Get-DictionaryValueFromFirstKeyFound -Dictionary $object -Key 'Arguments', 'args', 'a')
                $parameters     = Get-DictionaryValueFromFirstKeyFound -Dictionary $object -Key 'Parameters', 'params'

                if ($null -eq $Parameters) { $Parameters = @{} }

                if ($unresolvedPath -isnot [string] -or $unresolvedPath -notmatch '\S')
                {
                    throw 'When passing hashtables to the -Path parameter, the Path key is mandatory, and must contain a single string.'
                }

                if ($null -ne $parameters -and $parameters -isnot [System.Collections.IDictionary])
                {
                    throw 'When passing hashtables to the -Path parameter, the Parameters key (if present) must be assigned an IDictionary object.'
                }
            }
            else
            {
                $unresolvedPath = [string] $object
                $arguments      = @()
                $parameters     = @{}
            }

            if ($unresolvedPath -notmatch '[\*\?\[\]]' -and
                (& $script:SafeCommands['Test-Path'] -LiteralPath $unresolvedPath -PathType Leaf) -and
                (& $script:SafeCommands['Get-Item'] -LiteralPath $unresolvedPath) -is [System.IO.FileInfo])
            {
                $extension = [System.IO.Path]::GetExtension($unresolvedPath)
                if ($extension -ne '.ps1')
                {
                    & $script:SafeCommands['Write-Error'] "Script path '$unresolvedPath' is not a ps1 file."
                }
                else
                {
                    & $script:SafeCommands['New-Object'] psobject -Property @{
                        Path       = $unresolvedPath
                        Arguments  = $arguments
                        Parameters = $parameters
                    }
                }
            }
            else
            {
                # World's longest pipeline?

                & $script:SafeCommands['Resolve-Path'] -Path $unresolvedPath |
                & $script:SafeCommands['Where-Object'] { $_.Provider.Name -eq 'FileSystem' } |
                & $script:SafeCommands['Select-Object'] -ExpandProperty ProviderPath |
                & $script:SafeCommands['Get-ChildItem'] -Include *.Tests.ps1 -Recurse |
                & $script:SafeCommands['Where-Object'] { -not $_.PSIsContainer } |
                & $script:SafeCommands['Select-Object'] -ExpandProperty FullName -Unique |
                & $script:SafeCommands['ForEach-Object'] {
                    & $script:SafeCommands['New-Object'] psobject -Property @{
                        Path       = $_
                        Arguments  = $arguments
                        Parameters = $parameters
                    }
                }
            }
        }
    )

    # Here, we have the option of trying to weed out duplicate file paths that also contain identical
    # Parameters / Arguments.  However, we already make sure that each object in $Path didn't produce
    # any duplicate file paths, and if the caller happens to pass in a set of parameters that produce
    # dupes, maybe that's not our problem.  For now, just return what we found.

    $resolvedScriptInfo
}

function Get-DictionaryValueFromFirstKeyFound
{
    param ([System.Collections.IDictionary] $Dictionary, [object[]] $Key)

    foreach ($keyToTry in $Key)
    {
        if ($Dictionary.Contains($keyToTry)) { return $Dictionary[$keyToTry] }
    }
}

function Set-ScriptBlockScope
{
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [scriptblock]
        $ScriptBlock,

        [Parameter(Mandatory = $true, ParameterSetName = 'FromSessionState')]
        [System.Management.Automation.SessionState]
        $SessionState,

        [Parameter(Mandatory = $true, ParameterSetName = 'FromSessionStateInternal')]
        $SessionStateInternal
    )

    $flags = [System.Reflection.BindingFlags]'Instance,NonPublic'

    if ($PSCmdlet.ParameterSetName -eq 'FromSessionState')
    {
        $SessionStateInternal = $SessionState.GetType().GetProperty('Internal', $flags).GetValue($SessionState, $null)
    }

    [scriptblock].GetProperty('SessionStateInternal', $flags).SetValue($ScriptBlock, $SessionStateInternal, $null)
}

function Get-ScriptBlockScope
{
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [scriptblock]
        $ScriptBlock
    )

    $flags = [System.Reflection.BindingFlags]'Instance,NonPublic'
    [scriptblock].GetProperty('SessionStateInternal', $flags).GetValue($ScriptBlock, $null)
}


function SafeGetCommand
{
    <#
        .SYNOPSIS
        This command is used by Pester's Mocking framework.  You do not need to call it directly.
    #>

    return $script:SafeCommands['Get-Command']
}

function Set-PesterStatistics($Node)
{
    if ($null -eq $Node) { $Node = $pester.TestActions }

    foreach ($action in $Node.Actions)
    {
        if ($action.Type -eq 'TestGroup')
        {
            Set-PesterStatistics -Node $action

            $Node.TotalCount        += $action.TotalCount
            $Node.Time              += $action.Time
            $Node.PassedCount       += $action.PassedCount
            $Node.FailedCount       += $action.FailedCount
            $Node.SkippedCount      += $action.SkippedCount
            $Node.PendingCount      += $action.PendingCount
            $Node.InconclusiveCount += $action.InconclusiveCount
        }
        elseif ($action.Type -eq 'TestCase')
        {
            $node.TotalCount++

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

            $Node.Time += $action.Time
        }
    }
}

$snippetsDirectoryPath = "$PSScriptRoot\Snippets"
if ((& $script:SafeCommands['Test-Path'] -Path Variable:\psise) -and
    ($null -ne $psISE) -and
    ($PSVersionTable.PSVersion.Major -ge 3) -and
    (& $script:SafeCommands['Test-Path'] $snippetsDirectoryPath))
{
    Import-IseSnippet -Path $snippetsDirectoryPath
}

& $script:SafeCommands['Export-ModuleMember'] Describe, Context, It, In, Mock, Assert-VerifiableMocks, Assert-MockCalled, Set-TestInconclusive
& $script:SafeCommands['Export-ModuleMember'] New-Fixture, Get-TestDriveItem, Should, Invoke-Pester, Setup, InModuleScope, Invoke-Mock
& $script:SafeCommands['Export-ModuleMember'] BeforeEach, AfterEach, BeforeAll, AfterAll
& $script:SafeCommands['Export-ModuleMember'] Get-MockDynamicParameters, Set-DynamicParameterVariables
& $script:SafeCommands['Export-ModuleMember'] SafeGetCommand, New-PesterOption
& $script:SafeCommands['Export-ModuleMember'] Invoke-Gherkin, Invoke-GherkinStep, Find-GherkinStep, BeforeEachFeature, BeforeEachScenario, AfterEachFeature, AfterEachScenario, GherkinStep -Alias Given, When, Then, And, But
& $script:SafeCommands['Export-ModuleMember'] New-MockObject