in x-test.js [1231:1236]
static testLine(ok, number, description, directive, level) {
description = description.replace(/\n/g, ' ');
const okText = ok ? 'ok' : 'not ok';
const directiveText = directive ? ` # ${directive}` : '';
return `${XTestTap.level(level)}${okText} ${number} - ${description}${directiveText}`;
}