Functions/Invoke-ScriptBlock.ps1
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<#
.SYNOPSIS This function invokes a script block, catching an exception and generating an error if it occurs, and verifies the result. .DESCRIPTION This function invokes a script block, catching an exception and generating an error if it occurs, and verifies the result. The result verification is only performed if an expected result is provided. #> function Invoke-ScriptBlock { [CmdletBinding(PositionalBinding=$true)] param ( # The description of what the script block is accomplishing. [Parameter(Mandatory=$true)] [ValidateNotNullOrEmpty()] [String]$description, # The script block to execute [Parameter(Mandatory=$true)] [ValidateNotNull()] [ScriptBlock]$scriptBlock, # Indicates if the script block should have output. [Parameter(Mandatory=$false)] [Switch]$shouldHaveOutput, # The expected output from the script block. [Parameter(Mandatory=$false)] [ValidateNotNull()] $expectedOutput ) # Invoke the script block try { $output = & $scriptBlock $errorMessage = $null } # Exception while invoking the script block catch { $errorMessage = "Exception during '$($description)'.`r`n$($_.Exception.Message)" Write-Error $errorMessage } # Verify the output if no exception was thrown if ([String]::IsNullOrWhiteSpace($errorMessage)) { # Output is expected but not specified if ($shouldHaveOutput) { if (!$output) { $errorMessage = "Failed to '$($description)' - no output when an output is expected." Write-Error $errorMessage } } # Expected output is specified elseif ($expectedOutput) { if ($output -cne $expectedOutput) { $errorMessage = "Failed to '$($description)' - the output does not match the expected output." Write-Error $errorMessage } } } # Return the result of invoking the script block as well as the error message (if any) return [PSCustomObject]@{ PSTypeName = "Invoke-TryCatchVerify.Output" Output = $output ErrorMessage = $errorMessage } } |