Maybe you have an idea why:

const unlikeSelector = unlikeSpan
.parent()
.setscraperAttr('unlikeHeart', 'unlikeHeart')
.getSelectorByscraperAttr('unlikeHeart');

unlikeSpan is undefined here. So I guess likeSpan is not found in:

const likeSpan = scraper.findOne({
selector: 'span',
where: (el) => el.html() === 'Like',
});