如何正确测试模拟 Cmdlet 的错误变量值?

Question

我们试图在Pester测试中检查Invoke-CommandErrorVariable的值。但由于某种原因，-ErrorVariable没有实例化。

Describe 'test ErrorVariable' {
Mock Invoke-Command {
#[CmdletBinding()]
#param (
#    [String[]]$ComputerName,
#    $ScriptBlock
#)
$ErrorId = 'NetworkPathNotFound,PSSessionStateBroken'
$TargetObject = 'UnknownHost'
$ErrorCategory = [System.Management.Automation.ErrorCategory]::OpenError
$ErrorMessage = "Connecting to remote server $TargetObject failed with the following error message : WinRM cannot process the request. The following error occurred while using Kerberos authentication: Cannot find the computer $TargetObject. Verify that the computer exists on the network and that the name provided is spelled correctly. For more information, see the about_Remote_Troubleshooting Help topic."
$Exception = New-Object -TypeName System.InvalidOperationException -ArgumentList $ErrorMessage
$ErrorRecord = New-Object -TypeName System.Management.Automation.ErrorRecord -ArgumentList $Exception, $ErrorId, $ErrorCategory, $TargetObject
$ErrorRecord
}
it 'should be green because it should contain the TargetObject' {
Invoke-Command -ComputerName TestComputer -ScriptBlock {1} -ErrorVariable ConnectionError
$ConnectionError.TargetObject | Should -Be 'UnknownHost'
}
}

即使添加了[CmdletBinding()]选项，它仍然没有填充。我们在这里缺少什么？

Answer 1

你应该使用Write-Error：

Describe 'test ErrorVariable' {
Mock Invoke-Command {
$ErrorId = 'NetworkPathNotFound,PSSessionStateBroken'
$TargetObject = 'UnknownHost'
$ErrorCategory = [System.Management.Automation.ErrorCategory]::OpenError
$ErrorMessage = "Connecting to remote server $TargetObject failed with the following error message : WinRM cannot process the request. The following error occurred while using Kerberos authentication: Cannot find the computer $TargetObject. Verify that the computer exists on the network and that the name provided is spelled correctly. For more information, see the about_Remote_Troubleshooting Help topic."
$Exception = New-Object -TypeName System.InvalidOperationException -ArgumentList $ErrorMessage
Write-Error -ErrorId $ErrorId -TargetObject $TargetObject -Category $ErrorCategory -Message $ErrorMessage -Exception $Exception
}
it 'should be green because it should contain the TargetObject' {
Invoke-Command -ComputerName TestComputer -ScriptBlock {1} -ErrorVariable ConnectionError -ErrorAction SilentlyContinue
$ConnectionError.TargetObject | Should -Be 'UnknownHost'
}
}