Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.11%. Comparing base (77b1f64) to head (4960e78).
Report is 17 commits behind head on main.

@@             Coverage Diff              @@
##               main    #6969      +/-   ##
============================================
+ Coverage     90.09%   90.11%   +0.02%     
  Complexity     6600     6600              
============================================
  Files           730      730              
  Lines         19843    19852       +9     
  Branches       1955     1955              
============================================
+ Hits          17877    17890      +13     
+ Misses         1371     1367       -4     
  Partials        595      595              

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I don't see too many alternatives.

One other option I thought of was to add a catch(RuntimeException) at the API entry point of serialization, just to make sure that no runtimeexception escapes. But I thought this was too blunt of a strategy - maybe there's some situation where its appropriate to let a runtime exception bubble up and go uncaught.

I guess instead of UncheckedIOException could use a sneaky throw hack and throw the IOException without declaring it

How does this work?

Another alternative would be to reimplement the forEach and introduce a ThrowingConsumer, but that isn't desirable because we'd need to use iterator in our forEach variant while IdentityHashMap etc.

I considered this as well and reached the same conclusion. In the past, benchmarks have shows extra memory allocation using an iterator vs. forEach. The other more pressing problem is that one of types we need to iterate through is Attributes, which doesn't expose an iterator. Moving away from Attributes.forEach would mean calling Attributes.asMap() which is obviously too expensive.

I guess instead of UncheckedIOException could use a sneaky throw hack and throw the IOException without declaring it

How does this work?

I believe the most common way is to use generics together with unchecked cast like in https://github.com/open-telemetry/opentelemetry-java-instrumentation/blob/cf0f530dc177951f457ffc2bc21c61382d4a10b7/instrumentation/reactor/reactor-3.1/library/src/main/java/io/opentelemetry/instrumentation/reactor/v3_1/ContextPropagationOperator.java#L250 which exploits generics and an unchecked cast to trick compiler to think that you are actually throwing a runtime exception. Here someone tracked down the part of the jls that makes this possible. I first saw this in https://www.google.com/search?q=java+puzzlers, for some reason I think that @breedx-splk has the book, idk why I remember it, could be wrong. Another way this could be done is using Class.newInstance, unlike the newer reflection apis it does not wrap the exception from constructor in InvocationTargetException (this should be the reason why it is deprecated). Of course, since the checked exceptions are a java not a jvm concept, it is possible to generate a class that accepts an arbitrary exception and just rethrows it.

I believe the most common way is to use generics together with unchecked cast

Wow I didn't know that was possible. Fascinating!

I think the approach in this PR is most straight forward to understand and without seemingly any technical downside. So let's go with this, but thanks for sharing! I trust compile time errors with unhandled checked exceptions a little bit less now that I know that the absence of throws Exception doesn't guarantee the function won't produce a checked exception anyway 😅