使用 Pester 测试强制参数 [英] Testing for mandatory parameters with Pester

问题描述

我想弄清楚如何对丢失的参数进行 Pester 测试:

I'm trying to figure out how to have Pester test for parameters that are missing:

Find-Waldo.Tests.ps1

$here = Split-Path -Parent $MyInvocation.MyCommand.Path
$sut = (Split-Path -Leaf $MyInvocation.MyCommand.Path) -replace '\.Tests\.', '.'

Describe 'Mandatory paramters' {
    it  'ComputerName' {
        {
            $Params = @{
                #ComputerName = 'MyPc'
                ScriptName   = 'Test'
            }
            . "$here\$sut" @Params
        } | Should throw
    }
}

Find-Waldo.ps1

Param (
    [Parameter(Mandatory)]
    [String]$ComputerName,
    [String]$ScriptName
)

Function Find-Waldo {
    [CmdletBinding()]
    Param (
        [String]$FilePath
    )

    'Do something'
}

每次我尝试 assert 结果或简单地运行测试时，它都会提示我输入 ComputerName 参数而不是测试失败.

Every time I try to assert the result or simply run the test, it will prompt me for the ComputerName parameter instead of failing the test.

我在这里遗漏了一些非常明显的东西吗?有没有办法测试强制参数的存在?

Am I missing something super obvious here? Is there a way to test for the presence of mandatory parameters?

推荐答案

根据 Mathias 的评论，您无法真正测试是否缺少 Mandatory 参数，因为 PowerShell 会提示输入而不是抛出错误.根据 他从 Pester 团队链接的评论，您可以使用 Get-Command 测试脚本中的 Mandatory 参数设置(假设它是为该变量设置的唯一参数属性)

Per the comments from Mathias, you can't really test for whether a Mandatory parameter is missing because PowerShell prompts for it rather than throwing an error. Per the comment he linked to from the Pester team you could use Get-Command to test for the Mandatory parameter setting in the script (assuming it is the only parameter attribute set for that variable)

((Get-Command "$here\$sut").Parameters['ComputerName'].Attributes.Mandatory | Should Be $true

另一种选择是在这种情况下不使用强制参数，而是使用一个执行 Throw 作为参数默认值的脚本块:

An alternative option would be to not use Mandatory parameters in this instance, and instead have a script block that does a Throw as the default value of the parameter:

Param (
    [String]$ComputerName = $(Throw '-ComputerName is required'),
    [String]$ScriptName
)

如果脚本始终用作自动化流程的一部分(而不是通过用户执行)，这可能是首选，因为它允许您控制/捕获其行为并避免它在执行过程中卡住.然后，您可以按照最初建议的方式测试脚本:

If the script is always used as part of an automated process (instead of via user execution) this might be preferred as it allows you to control/capture its behavior and avoids it getting stuck during execution. You can then test the script as you had originally proposed:

Describe 'Mandatory paramters' {
    it  'ComputerName' {
        {
            $Params = @{
                #ComputerName = 'MyPc'
                ScriptName   = 'Test'
            }
            . "$here\$sut" @Params
        } | Should throw '-ComputerName is required'
    }
}

这篇关于使用 Pester 测试强制参数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！