Today: • PR: Finished with support of complex lambdas (multi-lined; with receiver) – +60 box tests pass (+43 before and +17 additionally now). • PR: Supported sharedBox (lambda captures) – +95 box tests pass. • Continued with switching to the new testing infra a bit. Still no luck as a huge amount of code there is bound to JVM

:(

Even classes that look like common ones judging by name. So looks like a deep understanding of the new infra is required to adapt our code to it, almost from scratch. Or maybe when JS IR is migrated to it, we could reuse it again. For now, I just ported some pieces of our code to the new infra, but it's only about 5-10% of what's needed to be ported. Although, there are some good news: I see how we can simplify our current testing even more, there is still some unused stuff left from JS. • Continued with IrTry but now the blocker is that exceptions can't be constructed (there is some JS-specific logic). Next time: • Prettify our testing a bit more: remove more unneeded pieces; take a look at ignored tests for Python Backend and maybe remove those declarations because we now don't depend on JS. • Research constructing exceptions.

Great progress, thanks! About this new testing infra, I'd advise to shelve it for even longer - it won't likely bring any big benefits and it's only consuming your time :D As you wrote, once JS target uses it, migration on our side should be much simpler 👍

I wanted to take a look after some time of break. I agree that I shouldn't spend much time on it now