# ensure the machine is in a clean state from the outset.
Remove-Variable -Name var1 -ErrorAction SilentlyContinue -Force

Describe "Remove-Variable" {
    It "Should throw an error when a dollar sign is used in the variable name place" {
	New-Variable -Name var1 -Value 4

	Remove-Variable $var1 -ErrorAction SilentlyContinue | Should Throw
    }

    It "Should not throw error when used without the Name field, and named variable is properly specified and exists" {
	New-Variable -Name var1 -Value 4

	Remove-Variable var1

	$var1 | Should Be #nothing.  it should be Nothing at all.
    }

    It "Should not throw error when used with the Name field, and named variable is specified and exists" {
	New-Variable -Name var1 -Value 2

	Remove-Variable -Name var1

	$var1 | Should Be #nothing.  it should be Nothing at all.
    }

    It "Should throw error when used with Name field, and named variable does not exist" {
	Remove-Variable -Name nonexistantVariable -ErrorAction SilentlyContinue | Should Throw
    }

    It "Should be able to remove a variable using the rv alias" {
	New-Variable var1 -Value 2

	$var1 | Should Be 2

	rv -Name var1

	$var1 | Should Be #nothing.  it should be Nothing at all.

    }

    It "Should be able to remove a set of variables using wildcard characters" {
	New-Variable tmpvar1 -Value "tempvalue"
	New-Variable tmpvar2 -Value 2
	New-Variable tmpmyvar1 -Value 234

	$tmpvar1   | Should Be "tempvalue"
	$tmpvar2   | Should Be 2
	$tmpmyvar1 | Should Be 234

	Remove-Variable -Name tmp*

	$tmpvar1   | Should Be #nothing.  it should be Nothing at all.
	$tmpvar2   | Should Be #nothing.  it should be Nothing at all.
	$tmpmyvar1 | Should Be #nothing.  it should be Nothing at all.
    }

    It "Should be able to exclude a set of variables to remove using the Exclude switch" {
	New-Variable tmpvar1 -Value "tempvalue"
	New-Variable tmpvar2 -Value 2
	New-Variable tmpmyvar1 -Value 234

	$tmpvar1   | Should Be "tempvalue"
	$tmpvar2   | Should Be 2
	$tmpmyvar1 | Should Be 234

	Remove-Variable -Name tmp* -Exclude *my*

	$tmpvar1   | Should Be #nothing.  it should be Nothing at all.
	$tmpvar2   | Should Be #nothing.  it should be Nothing at all.
	$tmpmyvar1 | Should Be 234
    }

    It "Should be able to include a set of variables to remove using the Include switch" {
	New-Variable tmpvar1 -Value "tempvalue"
	New-Variable tmpvar2 -Value 2
	New-Variable tmpmyvar1 -Value 234
	New-Variable thevar -Value 1

	$tmpvar1   | Should Be "tempvalue"
	$tmpvar2   | Should Be 2
	$tmpmyvar1 | Should Be 234
	$thevar    | Should Be 1

	Remove-Variable -Name tmp* -Include *my*

	$tmpvar1   | Should Be "tempvalue"
	$tmpvar2   | Should Be 2
	$tmpmyvar1 | Should Be #nothing.  it should be Nothing at all.
	$thevar    | should Be 1

	Remove-Variable tmpvar1
	Remove-Variable tmpvar2
	Remove-Variable thevar

    }

    It "Should throw an error when attempting to remove a read-only variable and the Force switch is not used" {
	New-Variable -Name var1 -Value 2 -Option ReadOnly

	Remove-Variable -Name var1 -ErrorAction SilentlyContinue | Should Throw

	$var1 | Should Be 2

	Remove-Variable -Name var1 -Force
    }

    It "Should not throw an error when attempting to remove a read-only variable and the Force switch is used" {
	New-Variable -Name var1 -Value 2 -Option ReadOnly

	Remove-Variable -Name var1 -Force

	$var1 | Should Be # Nothing.  It should be nothing at all.
    }

    Context "Scope Tests" {
	It "Should be able to remove a global variable using the global switch" {
	    New-Variable -Name var1 -Value "context" -Scope global

	    Remove-Variable -Name var1 -Scope global

	    $var1 | Should Be #Nothing.
	}

	It "Should not be able to clear a global variable using the local switch" {
	    New-Variable -Name var1 -Value "context" -Scope global

	    Remove-Variable -Name var1 -Scope local -ErrorAction SilentlyContinue | Should Throw

	    $var1 | Should Be "context"

	    Remove-Variable -Name var1 -Scope global
	    $var1 | Should Be # Nothing
	}

	It "Should not be able to clear a global variable using the script switch" {
	    New-Variable -Name var1 -Value "context" -Scope global

	    Remove-Variable -Name var1 -Scope local -ErrorAction SilentlyContinue | Should Throw

	    $var1 | Should Be "context"

	    Remove-Variable -Name var1 -Scope global
	    $var1 | Should Be # Nothing
	}

	It "Should be able to remove an item locally using the local switch" {
	    New-Variable -Name var1 -Value "context" -Scope local

	    Remove-Variable -Name var1 -Scope local -ErrorAction SilentlyContinue | Should Throw

	    $var1 | Should Be # Nothing
	}

	It "Should be able to remove an item locally using the global switch" {
	    New-Variable -Name var1 -Value "context" -Scope local

	    Remove-Variable -Name var1 -Scope global -ErrorAction SilentlyContinue | Should Throw

	    $var1 | Should Be "context"

	    Remove-Variable -Name var1 -Scope local
	    $var1 | Should Be # Nothing
	}

	It "Should be able to remove a local variable using the script scope switch" {
	    New-Variable -Name var1 -Value "context" -Scope local

	    Remove-Variable -Name var1 -Scope script -ErrorAction SilentlyContinue | Should Throw

	    $var1 | Should Be "context"

	    Remove-Variable -Name var1 -Scope local
	    $var1 | Should Be # Nothing
	}

	It "Should be able to remove a script variable created using the script switch" {
	    New-Variable -Name var1 -Value "context" -Scope script

	    Remove-Variable -Name var1 -Scope script | Should Throw

	    $var1 | Should Be # Nothing
	}

	It "Should not be able to remove a global script variable that was created using the script scope switch" {
	    New-Variable -Name var1 -Value "context" -Scope script

	    Remove-Variable -Name var1 -Scope global -ErrorAction SilentlyContinue | Should Throw

	    $var1 | Should Be "context"
	}
    }
}


Describe "Remove-Variable basic functionality" -Tags DRT{
	It "Remove-Variable variable should works"{
		New-Variable foo bar
		Remove-Variable foo
		$var1 = Get-Variable -Name foo -EA SilentlyContinue
		$var1 | Should BeNullOrEmpty
	}
	
	It "Remove-Variable Constant variable should throw SessionStateUnauthorizedAccessException"{
		New-Variable foo bar -Option Constant
		try
		{
			Remove-Variable foo -EA Stop
			Throw "Execution OK" 
		}
		catch 
		{
			$_.CategoryInfo | Should Match "SessionStateUnauthorizedAccessException"  
			$_.FullyQualifiedErrorId | Should be "VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveVariableCommand"
		}
	}
	
	It "Remove-Variable ReadOnly variable should throw SessionStateUnauthorizedAccessException and force remove should work"{
		New-Variable foo bar -Option ReadOnly
		try
		{
			Remove-Variable foo -EA Stop
			Throw "Execution OK"
		}
		catch 
		{
			$_.CategoryInfo| Should Match "SessionStateUnauthorizedAccessException"  
			$_.FullyQualifiedErrorId | Should be "VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveVariableCommand"
		}
		Remove-Variable foo -Force
		$var1 = Get-Variable -Name foo -EA SilentlyContinue
		$var1 | Should BeNullOrEmpty
	}
	
	It "Remove-Variable Constant variable should throw SessionStateUnauthorizedAccessException and force remove should also throw exception"{
		New-Variable foo bar -Option Constant
		try
		{
			Remove-Variable foo -EA Stop
			Throw "Execution OK" 
		}
		catch 
		{
			$_.CategoryInfo | Should Match "SessionStateUnauthorizedAccessException"  
			$_.FullyQualifiedErrorId | Should be "VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveVariableCommand"
		}
		
		try
		{
			Remove-Variable foo -Force -EA Stop
			Throw "Execution OK" 
		}
		catch 
		{
			$_.CategoryInfo | Should Match "SessionStateUnauthorizedAccessException"  
			$_.FullyQualifiedErrorId | Should be "VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveVariableCommand"
		}
	}
	
	It "Remove-Variable variable in new scope should works and Get-Variable with different scope should have different result"{
		New-Variable foo bar
		&{
			Clear-Variable foo
			Remove-Variable foo
			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 "None"
		$var1.Description | Should Be ""
		
	}
}