PowerShellスクリプトにユニットテストを埋め込むい

unit-test-include.ps1

param(
    [parameter(Mandatory, Position=0, ParameterSetName="Normal")]
    [Int]$Number,

    [parameter(ParameterSetName="Normal")]
    [String]$OutputPath = "out.txt",

    [parameter(ParameterSetName="Test")]
    [switch]$Test = $false
)

function Get-Double([Int]$Number) {
    $Number * 2
}

function Write-Result([String]$Path) {
    $input > $Path
}

function Main {
    Get-Double $Number | Write-Result $OutputPath
}

function Test {
    Invoke-Pester -Script $MyInvocation.MyCommand.Path  # 自分をテストスクリプトと見做してPesterを実行する
}

if ($Test) {
    Test
} else {
    Main
}


# ----- ここからテスト -----

Describe "Get-Double" {
    It "2なら4" {
        Get-Double 2 | Should Be 4
    }
    It "3なら6" {
        Get-Double 3 | Should Be 6
    }
}

Describe "Write-Result" {
    It "2をoutに" {
        echo 2 | Write-Result TestDrive:\out
        Get-Content TestDrive:\out | Should Be 2
    }
    It "helloをworldに" {
        echo hello | Write-Result TestDrive:\world
        Get-Content TestDrive:\world | Should Be "hello"
    }
}