Script that helps me do TDD with PowerShell and Pester in Visual Studio Code

_workinprogress.md

Run Pester Unit Tests in Visual Studio Code

read more about what it is on my blog

launch.json

{
    "version": "0.2.0",
    "configurations": [

        {
            "type": "PowerShell",
            "request": "launch",
            "name": "Test workinprogress",
            "script": "workinprogress.ps1",
            "args": [ "${workspaceFolder}", "${workspaceFolder}/tests", "${file}", "${lineNumber}" ]
        },
        {
            "type": "PowerShell",
            "request": "launch",
            "name": "Test all",
            "script": "Invoke-Pester",
            "args": [ "${workspaceFolder}/tests/", "-Show Fails" ]
        }
    ]
}

workinprogress.ps1

param(
    [string]$workspace, 
    [string]$testsFolder,
    [string]$fullPath,
    [int]$line
    )

$script:file = Split-Path $fullPath -Leaf
$script:testsRun = $false 

if (Test-Path "$workspace\*.psm1") {
    # if it is a module workspace, reload the module
    Import-Module $workspace -Force 
}

if ($script:file -like "*.Tests.ps1") {
    # if it is a pester file try to get the 'current' tag
    $code = [Management.Automation.Language.Parser]::ParseInput((Get-Content $fullPath -Raw), [ref]$null, [ref]$null)

    $firstTag = $null 

    $code.FindAll([Func[Management.Automation.Language.Ast, bool]] {
        param($ast) 
        $ast.Extent.StartLineNumber -le $line -and 
        $ast.Extent.EndLineNumber -ge $line -and
        $ast.CommandElements -and 
        $ast.CommandElements[0].Value -eq "describe"
    }, $true) | ForEach-Object {
        $ce = $psitem.CommandElements
        $tagsIndex = $ce.IndexOf(($ce | Where-Object ParameterName -in ("Tag","Tags"))) + 1
        $tags = if ($tagsIndex -and $tagsIndex -lt $ce.Count) { $ce[$tagsIndex].Extent }

        if ($tags) {
            $firstTag = $tags.Text.Split(',')[0].Trim().Trim('"').Trim("'")
        }
    }

    if ($firstTag) {
        # if first tag has been found execute the test only for that tag 
        Invoke-Pester -Script $fullPath -Tag $firstTag
    } else {
        # if there is no tag execute the whole file
        Invoke-Pester -Script $fullPath  
    }

    $script:testsRun = $true
} else {
    # not a pester file - let's try to find matching test files 
    
    if (Test-Path ($fullPath -replace ".ps1$", ".Tests.ps1")) {
        # there is tests file in the same folder 
        Invoke-Pester -Script ($fullPath -replace ".ps1$", ".Tests.ps1")
    }

    if (Test-Path $testsFolder) {
        (Get-ChildItem $testsFolder -Recurse -Include ($script:file -replace ".ps1$", ".Tests.ps1")) | ForEach-Object {
            Invoke-Pester -Script $PSItem.FullName
        }
    }

    $script:testsRun = $true 
}

if (!$script:testsRun) {
    Write-Host "There is nothing to run. Consider writing a unit test file for the $script:file file."
}