https://news.ycombinator.com/item?id=8308578
after first asking someone to cite such a problem.
AFAICT the "isn't a problem in practice" happy-talk is all coming from Dart insiders. Does this shoe fit?
Anyway, it's a real Dart bug that drives potential users away. And why is JS bignum support -- which Google for-sure could have championed in Ecma TC39 and prototype-implemented in V8 -- just an "It would be nice" thing?
(It is not difficult to support suffixes for new value types, e.g. 0m for decimal and 0n or better for bignum. This is on the ES7 agenda. For more on range analysis and other/better optimization options, see https://news.ycombinator.com/item?id=6950475.)
Trusting checked-mode test coverage is bold in light of this bug, where bold might be "stupid" or "you're fired". As I wrote once in this thread already, Murphy was an optimist.