Left-pad was as far as I know written by one person. Had they used underscore or lodash or any of those bazillions of utility libraries out there, that have real code review, and are actually making money, this would be way less likely.

That's why I'd look for a graph algorithms library first, not a topo sort specifically, I'd be looking for larger one size fits all libs likely to be maintained by a larger group and have more eyeballs on them.