I changed everything into

BigDecimal

but the result is still the same.

Unless whole JVM is horribly broken it should work 🙂

Note, I intentionally used your approach to make my code similar to yours, usually with BigDecimals you would write something like:

val totalHt = items.fold(BigDecimal.ZERO, BigDecimal::add)

I mean you're probably initializing

BigDecimal

with a

Double

, check this screenshot

the nice rounded numbers you see during debugging is just eye candy.

Using floats or doubles for finance is like a mortal sin for a developer 😄 These types just are not designed to work like we need them to for financial stuff, for some other stuff too if you believe the military anecdote in this article: https://dzone.com/articles/never-use-float-and-double-for-monetary-calculatio

And here's more in-depth information from Oracle: https://blogs.oracle.com/corejavatechtips/the-need-for-bigdecimal (linked from the dzone article above)

Thanks a lot for you help. I think I have my solution.

I don't know what you're using for mapping, but e.g. Spring Data MongoDB supports Java/Kotlin

BigDecimal

<-> BSON

String

mapping

Oh, actually it seems MongoDB 3.4 did add a suitable decimal type: https://docs.mongodb.com/manual/tutorial/model-monetary-data/#numeric-decimal Check if your mapper supports it, or use strings.

I am becoming crazy... I've added logging, they do not appear. I raised an exception in the middle of my code, to make crash my app on purpose, nothing happen, it's just continuing like if it was not there.

hitting the button is launching a new debug session and you might be still interacting with an old one

oh huh

you might want to check in the run configuration to see if “Allow running in parallel” is enabled? Do you get a warning when you try to restart a debugging session?