PowerShell/test/powershell/Clear-Variable.Tests.ps1

Describe "Clear-Variable DRT Unit Tests" -Tags DRT{
	It "Clear-Variable normal variable Name should works"{
		Set-Variable foo bar
		Clear-Variable -Name foo
		$var1=Get-Variable -Name foo
		$var1.Name|Should Be "foo"
		$var1.Value|Should Be $null
		$var1.Options|Should Be "None"
		$var1.Description|Should Be ""
	}

	It "Clear-Variable ReadOnly variable Name should throw exception and force Clear-Variable should works"{
		Set-Variable foo bar -Option ReadOnly

		try {
			Clear-Variable -Name foo -EA Stop
			Throw "Execution OK"
		}
		catch {
			$_.CategoryInfo| Should Match "SessionStateUnauthorizedAccessException"
			$_.FullyQualifiedErrorId | Should Be "VariableNotWritable,Microsoft.PowerShell.Commands.ClearVariableCommand"
		}

		Clear-Variable -Name foo -Force
		$var1=Get-Variable -Name foo
		$var1.Name|Should Be "foo"
		$var1.Value|Should Be $null
		$var1.Options|Should Be "ReadOnly"
		$var1.Description|Should Be ""
	}

	It "Clear-Variable normal variable Name with local scope should works"{
		Set-Variable foo bar
		&{
			Set-Variable foo baz
			$foo | should be baz
			Clear-Variable -Name foo -Scope "local"

			$var1=Get-Variable -Name foo -Scope "local"
			$var1.Name|Should Be "foo"
			$var1.Value|Should Be $null
			$var1.Options|Should Be "None"
			$var1.Description|Should Be ""
		}

		$var1=Get-Variable -Name foo
		$var1.Name|Should Be "foo"
		$var1.Value|Should Be "bar"
		$var1.Options|Should Be "None"
		$var1.Description|Should Be ""
	}

	It "Clear-Variable Private variable Name should works and Get-Variable with local scope should throw exception"{
		Set-Variable foo bar -Option Private
		&{
			try {
					Get-Variable -Name foo -Scope local -EA Stop
					Throw "Execution OK"
			}
			catch {
					$_.CategoryInfo| Should Match "ItemNotFoundException"
					$_.FullyQualifiedErrorId | Should Be "VariableNotFound,Microsoft.PowerShell.Commands.GetVariableCommand"
			}
		}

		$var1=Get-Variable -Name foo
		$var1.Name|Should Be "foo"
		$var1.Value|Should Be "bar"
		$var1.Options|Should Be "Private"
		$var1.Description|Should Be ""
	}

	It "Clear-Variable normal variable Name with local scope should works in different scope"{
		Set-Variable foo bar
		&{
			Set-Variable foo baz
			Clear-Variable -Name foo -Scope "local"

			$var1=Get-Variable -Name foo -Scope "local"
			$var1.Name|Should Be "foo"
			$var1.Value|Should Be $null
			$var1.Options|Should Be "None"
			$var1.Description|Should Be ""
		}

		$var1=Get-Variable -Name foo
		$var1.Name|Should Be "foo"
		$var1.Value|Should Be "bar"
		$var1.Options|Should Be "None"
		$var1.Description|Should Be ""

		$var1=Get-Variable -Name foo -Scope "local"
		$var1.Name|Should Be "foo"
		$var1.Value|Should Be "bar"
		$var1.Options|Should Be "None"
		$var1.Description|Should Be ""
	}
}

Describe "Clear-Variable" {
		BeforeEach {
	$var1 = 3
		}

		It "Should be able to clear a variable using the Name switch" {
	Clear-Variable -Name var1
	$var1 | Should BeNullOrEmpty
	{ Get-Variable var1 } | Should Not Throw
		}

		It "Should be able to clear a variable without using the Name switch" {
	Clear-Variable var1
	$var1 | Should BeNullOrEmpty
	{ Get-Variable var1 } | Should Not Throw
		}

		It "Should work using the clv alias" {
	clv -Name var1
	$var1 | Should BeNullOrEmpty
	{ Get-Variable var1 } | Should Not Throw
		}

		It "Should be able to include a set of variables to clear" {
	$var1      = 2
	$var2      = 3
	$var3      = 4
	$variable1 = 23
	$variable2 = 4
	$variable3 = 2
	$w         = 3

	Clear-Variable -Name w, vari* -Include w, vari*

	$variable1 | Should BeNullOrEmpty
	$variable2 | Should BeNullOrEmpty
	$variable3 | Should BeNullOrEmpty
	$w         | Should BeNullOrEmpty

	$var1 | Should Not BeNullOrEmpty
	$var2 | Should Not BeNullOrEmpty
	$var3 | Should Not BeNullOrEmpty

		}

		It "Should be able to exclude a set of variables to clear" {
	$var1      = 2
	$var2      = 3
	$var3      = 4
	$variable1 = 23
	$variable2 = 4
	$variable3 = 2
	$w         = 3

	Clear-Variable -Name w, vari* -Exclude var*

	$variable1 | Should Not BeNullOrEmpty
	$variable2 | Should Not BeNullOrEmpty
	$variable3 | Should Not BeNullOrEmpty
	$var1      | Should Not BeNullOrEmpty
	$var2      | Should Not BeNullOrEmpty
	$var3      | Should Not BeNullOrEmpty

	$w         | Should BeNullOrEmpty
		}

		It "Should be able to pass the cleared object through the pipeline using the passthru switch" {
	{ Clear-Variable -Name var1 -PassThru | Format-Wide -Property Value } | Should Not Throw
		}

		It "Should not clear environment variables" {
	$env:TEMPVARIABLE = "test data"

	{Clear-Variable -Name env:TEMPVARIABLE -ErrorAction Stop} | Should Throw
		}

		It "Should clear variable even if it is read-only using the Force parameter" {
	try
	{
		New-Variable -Name var2 -Option ReadOnly -Value 100

		Clear-Variable -Name var1
		Clear-Variable -Name var2 -Force

		$var1 | Should BeNullOrEmpty
		$var2 | Should BeNullOrEmpty
	}
	finally
	{
		Remove-Variable -Name var2 -Force
	}
		}

		It "Should throw error when trying to clear variable that is read-only without using the Force parameter" {
		New-Variable -Name var2 -Option ReadOnly -Value 100
		try {
			Clear-Variable -Name var2 -ea stop
			Throw "Execution OK"
		}
		catch {
			$_.FullyQualifiedErrorId | should be "VariableNotWritable,Microsoft.PowerShell.Commands.ClearVariableCommand"
		}
		$var2 | Should Not BeNullOrEmpty

		Remove-Variable -Name var2 -Force
		}

		Context "Scope Tests" {
	# This will violate the DRY principle.  Tread softly.

	It "Should be able to clear a global scope variable using the global switch" {
			New-Variable globalVar -Value 1 -Scope global -Force

			Clear-Variable -Name globalVar -Scope global

			$globalVar | Should BeNullOrEmpty
	}

	It "Should not be able to clear a global scope variable using the local switch" {
			New-Variable globalVar -Value 1 -Scope global -Force

			{Clear-Variable -Name globalVar -Scope local -ErrorAction Stop} | Should Throw
	}

	It "Should not be able to clear a global variable using the script scope switch" {
			New-Variable globalVar -Value 1 -Scope global -Force

			{Clear-Variable -Name localVar -Scope script -ErrorAction Stop} | Should Throw
	}

	It "Should be able to clear an item locally using the local switch" {
			New-Variable localVar -Value 2 -Scope local -Force

			Clear-Variable -Name localVar -Scope local

			$localVar | Should BeNullOrEmpty

			{Clear-Variable -Name localVar -Scope script -ErrorAction Stop} | Should Throw
	}

	It "Should not be able to clear an item locally using the global switch" {
			New-Variable localVar -Value 2 -Scope local -Force

			{Clear-Variable -Name localVar -Scope global -ErrorAction Stop} | Should Throw
	}

	It "Should not be able to clear a local variable using the script scope switch" {
			New-Variable localVar -Value 2 -Scope local -Force

			{Clear-Variable -Name localVar -Scope script -ErrorAction Stop} | Should Throw
	}

	It "Should be able to clear a script variable created using the script switch" {
			{
		New-Variable -Name derp2 -Value 3 -Scope script -Force

		Clear-Variable -Name derp2 -Scope script
			}| Should Not Throw
	}

	It "Should be able to clear a global script variable that was created using the script scope switch" {
			{
		New-Variable -Name derpx -Value 4 -Scope script -Force

		Clear-Variable -Name derpx -Scope script
			} | Should Not Throw
	}
		}
}