On the input side, I would guess the problem is that the minifier in question uses a parse tree with a not-quite-perfect grammar. It sees clearMenus()

On the input side, I would guess the problem is that the minifier in question uses a parse tree with a not-quite-perfect grammar. It sees clearMenus() !isActive && $parent.toggleClass('open') and parses it the same way it would have done clearMenus() !isActive && $parent.toggleClass('open') On the output side, using ; is simpler to program (A\nB only means A;B in some cases, depending on B). And you'll receive fewer flames for it.