Get-TestParents

get-testparents.ps1

function Get-TestParents {
    <#
    .SYNOPSIS
    Returns any parents not already known, top-down first, so that a hierarchy can be created in a streaming manner
    #>
    param (
        #Test to fetch parents of. For maximum efficiency this should be done one test at a time and then stack processed
        [Parameter(Mandatory,ValueFromPipeline)][Pester.Test[]]$Test,
        [HashSet[Pester.Block]]$KnownParents = [HashSet[Pester.Block]]::new()
    )

    begin {
        [Stack[Pester.Block]]$NewParents = [Stack[Pester.Block]]::new()
    }
    process {

        # Output all parents that we don't know yet (distinct parents), in order from the top most
        # to the child most.
        foreach ($TestItem in $Test) {
            $NewParents.Clear()
            $parent = $TestItem.Block

            while ($null -ne $parent -and -not $parent.IsRoot) {
                if (-not $KnownParents.Add($parent)) {
                    # We know this parent, so we must know all of its parents as well. 
                    # We don't need to go further.
                    break
                }

                $NewParents.Push($parent)
                $parent = $parent.Parent
            }

            # Output the unknown parent objects from the top most, to the one closest to our test.
            foreach ($p in $NewParents) { $p }
        }
    }
}