如何为我的PowerShell函数编写Pester测试

Question

I have the following function: For this function I'm required to write a Pester code that will have 100% coverage.

function buildFilterString {
[CmdletBinding()]
param (
    [string] $input_str, 
    [char] $delimiter
)

$out = $null

$input_str -split $delimiter | ForEach-Object {
    $item = $_
    $out += "'" + $item + "',"
}

$out.Substring(0,$out.Length-1)
}

As I understood the test should look like this, but I'm not sure how to write the "different cases" in the test.

$moduleRoot = Resolve-Path "$PSScriptRoot\.."
$moduleName = Split-Path $moduleRoot -Leaf
$cred = Get-Credential

Describe "Demonstarting Code Coverage of: $moduleName" {

 It "Calls Function: builedFilterString" {
    {buildFilterString -input_str "happy" -delimiter ';'} | Should Be 
     "happy"
  }
}

Answer 1

In this case you just need to make sure the -input_str contains the specified -delimiter and all you're code is covered. You could keep the stated case were the -input_str does not contain the specified -delimiter , to test the edge case (which will fail by the way, because $out will stay $null ).