Shared state between DSL keywords in Pester

scopechecks.ps1

# in module scope
$script:pester


function describe () { 
    $script:pester.EnterBlock("describe") 
}

function it () { 
    if ($script:pester.Block -ne "Describe") {
        throw "it can only be in describe"
    }
    $script:pester.EnterBlock("it") 
} 

function should () {
    if ($script:pester.Block -ne "It") { 
        throw "should can only be in it" 
    }
}