V8 does actually check if the outer variables are referenced by the inner function. There's a misconception amongst a disturbing number of programmers that it's

V8 does actually check if the outer variables are referenced by the inner function. There's a misconception amongst a disturbing number of programmers that it's impossible to memory leak in a garbage collected language. For some reason I've found this particularly prevalent amongst C# developers, but no language community is immune from it. In truth there are myriad ways to very casually and accidentally create pools of references that can't be garbage collected. I'll leave finding these as an exercise for the reader to google. here's an old article by Douglas Crockford about a particular memory leak in IE's garbage collector that persisted for a very long time: https://crockford.com/javascript/memory/leak.html https://crockford.com/javascript/memory/leak.html