powershell - 从 PowerShell cmdlet 返回错误的最佳做法是什么？

Question

我正在为我们的应用程序配置需求编写一个基于 PowerShell 的 XML 模块。以下是功能之一。

<#
.Synopsis
   To update an XML attribute value
.DESCRIPTION
   In the XML file for a particular attribute, if it contains valueToFind then replace it with valueToReplace
.EXAMPLE

-------------------------------Example 1 -------------------------------------------------------------------
   Update-XMLAttribute -Path "C:\web.Config" -xPath "/configuration/system.serviceModel/behaviors/serviceBehaviors/behavior/serviceMetadata" -attribute "externalMetadataLocation" -valueToFind "http:" -ValueToReplace "https:"

   Look for the XPath expression with the attribute mentioned and search whether the value contains "http:". If so, change that to "https":
.EXAMPLE

-------------------------------Example 2 -------------------------------------------------------------------
   Update-XMLAttribute -Path "C:\web.Config" -xPath "/configuration/system.serviceModel/behaviors/serviceBehaviors/behavior/serviceMetadata" -attribute "externalMetadataLocation" -valueToFind "http:" -ValueToReplace "https:"

   Same as Example 1 except that the attribute name is passed as part of the XPath expression

#>
function Update-XMLAttribute
{
    [CmdletBinding()]
    [OutputType([int])]
    Param
    (
        # Web configuration file full path
        [Parameter(Mandatory=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [string]$Path,

        # XPath expression up to the parent node
        [string] $xPath,
        # This parameter is optional if you mentioned it in xPath itself
        [string] $attribute,

        [string] $valueToFind,

        [string] $ValueToReplace
    )

    Try
    {
        If (Test-path -Path $Path)
        {
                    $xml = New-Object XML
                    $xml.Load($Path)

                    # If the xPath expression itself contains an attribute name then the value of attribute will be processed and taken
                    If ($xPath.Contains("@")) {
                        $xPath, $attribute = $xPath -split '/@', 2
                    }

                    # Getting the node value using xPath
                    $Items  = Select-Xml -XML $xml -XPath $xPath
                    ForEach ($Item in $Items)
                    {

                        $attributeValue = $Item.node.$attribute
                        Write-Verbose "Attribute value is $attributeValue "

                        if ($attributeValue.contains($valueToFind)) {


                            Write-Verbose "In the attribute $attributeValue - $valueToFind is to be repalced with $ValueToReplace"
                            $Item.node.$attribute = $attributeValue.replace($valueToFind, $ValueToReplace)
                        }
                    }

                    $xml.Save($Path)
                    Write-Verbose " Update-XMLAttribute is completed successfully"
        }
        Else {
            Write-Error " The $path is not present"
        }

    }
    Catch {
        Write-Error "$_.Exception.Message"
        Write-Error "$_.Exception.ItemName"
        Write-Verbose " Update-XMLAttribute is failed"
    }
} # End Function Update-XMLAttribute

由于这个 cmdlet 将被许多人使用，我认为简单地写入控制台并不是正确的方法。

截至目前，在我的脚本中，如果没有错误，我可以假设我的脚本已成功完成。

从 PowerShell cmdlet 获取结果以便消费者知道它是否成功完成的标准做法是什么？

Answer 1

你的函数应该 throw 如果遇到错误。让调用者决定如何处理错误(忽略、记录消息、终止等等)。