chriskuech

$ErrorActionPreference = "Stop"

function Assert-True {
    [CmdletBinding()] # add ErrorAction support
    Param([boolean]$Value)
    if (-not $Value) {
        throw "Failed assertion"
    }
}

chriskuech

$ErrorActionPreference = "Stop"

# an error will thrown and caught, so you wont see it
try {
  throw "something bad happened..."
} catch {
  Write-Host "It looks like $_, but everything's still fine."
} finally {
  Write-Host "I knew I would get here eventually"
}

chriskuech

function div($n, $d) {$n / $d} # a seemingly pure function
div 1 0 # throws 'Attempted to divide by zero' error

chriskuech

# this outer scope contains only immutable variables
$var = & {
    # this scope contains mutable temporary variables
    $queue = [System.Collections.Generic]::new()
    $queue.Enqueue(@{Id = 1})
    while ($queue.Count) {
        $jobInfo = $queue.Dequeue()
        $newJobInfo = Update-RemoteJob $jobInfo # non-deterministic
        if ($newJobInfo) {
            $queue.Enqueue($newJobInfo)

chriskuech

function Invoke-AfterEach {
    Param(
        [scriptblock[]]$ScriptBlock,
        [scriptblock]$OnTaskComplete
    )
    $ScriptBlock | % {
        Start-Job {
            Param($action, $callback)
            &$action
            &$callback

chriskuech

$job = Start-Job $action
... # do some other stuff
$job | Wait-Job

chriskuech

# invokes the action, then calls the callback upon completion
function Invoke-Then([scriptblock]$action, [scriptblock]$callback) {
    Start-Job {
        &$using:action
        &$using:callback
    }
}

chriskuech

$job = Start-Job $action # `$action` will be executed asynchronously
Invoke-NextCommand # will be called before `$action` has completed
$job | Wait-Job -Timeout 60 | Receive-Job

chriskuech

$d = $a | % {&$aToB $_} | % {&$bToC $_} | % {&$cToD $_}

chriskuech

Import-Module functional

$aToD = $aToB, $bToC, $cToD | Merge-ScriptBlock