.test.ps1

$Version = $PSVersionTable.PSVersion
${5.0} = [version]'5.0.0'
${5.1} = [version]'5.1.0'
${6.1} = [version]'6.0.9999' # 6.1-preview.2
if ($Version -lt ${5.0}) {return task test5}

task Test-1.fails {
	($r = try {.\Test-1.fails.ps1} catch {$_})
	if ($Version -ge ${6.1}) {
		equals $r.FullyQualifiedErrorId 'System.NullReferenceException,Test-1.fails.ps1'
	}
	elseif ($Version -ge ${5.1}) {
		# weird error "Parameter name: type" with no source
		equals $r.FullyQualifiedErrorId 'System.ArgumentNullException,Test-1.fails.ps1'
	}
	else {
		equals $r.Count 2
		assert ($r[0].GetType().FullName -cmatch '^<\w{8}>\.A$')
		equals $r[1].FullyQualifiedErrorId TypeNotFound
	}
}

task Test-2.works {
	($r = .\Test-2.works.ps1)
	equals $r.Count 2
	$r0 = $r[0].GetType().FullName
	$r1 = $r[1].GetType().FullName
	assert ($r0 -cmatch '^<\w+>\.A$')
	assert ($r1 -cmatch '^<\w+>\.A$')
	assert ($r0 -ne $r1)
}