PowerShell Param()语句+错误陷阱 [英] PowerShell Param() statement + error trap

问题描述

我们使用以下语句使TeamCity能够识别PowerShell部署脚本中的错误:

We're using the following statement to enable TeamCity to recognize errors in our PowerShell deployment scripts:

trap { $host.SetShouldExit(1) }

这很好用，但是，因为Param(...)必须是第一个语句，所以我们必须使用以下顺序:

This works fine, however, since Param(...) needs to be the very first statement we have to use this order:

Param(
    ...
)

Set-StrictMode -Version 2.0
$ErrorActionPreference = "Stop"
trap { $host.SetShouldExit(1) }

在Param()评估期间，是否还可以捕获错误?例如.如果我们省略了必填参数，TeamCity目前将无法检测到.

Is there any way to also trap errors during the Param() evaluation? E.g. if we omit a mandatory parameter, TeamCity is not able to detect this at the moment.

推荐答案

这是对Powershell的又一个烦人的疏忽.我发现解决此Powershell错误的最佳方法是推出您自己的强制性验证.它是更多的代码，但清晰，简单且具有故障保护功能.

This is yet another annoying oversight of Powershell. I find the best way to workaround this Powershell bug is to roll your own mandatory verification. It's more code, but clear, simple and fail-safe.

首先从参数声明中删除强制性标志，并在脚本开头检查是否为空.

First remove the mandatory flag from the param declaration and check for null or empty at the beginning of the script.

param (
    [string] $required_param
)
# Check required params
if ([string]::IsNullOrEmpty($required_param)) {
    Write-Host "The required_param is required."
    exit 1;
}

此外，您可以使用常规File参数调用脚本:

Plus you can call your script with the regular File argument:

powershell -File foo.ps1

希望这会有所帮助.

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