[firebase_crashlytics] Handle case where function isn't in class for stack

[rmtmckenzie]

Description

Currently, the stacktrace parser can't handle it when there is a method without a class in dart - it instead throws its own exception and loses the original one!

This PR handles the case where there is no class name.

There is a slight caveat to the fix on Android - firebase reporting uses a StackTraceElement which requires a class (which makes sense in Java since you can't have Class-less methods), so on Android class-less methods are reported as .<functionName> whereas on iOS they are simply reported as <className>.

I don't think this is a big problem as there seem to be other differences between how the stacktraces are reported on Android and iOS anyways.

i.e. iOS:

Android:

Related Issues

• [firebase_crashlytics] RangeError: Value not in range: -1 flutter#32178

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[collinjackson]

Looks great! Thanks for adding a test. One suggestion, which I'll commit for you.

[collinjackson]

I think className ?? "" would be more readable

Suggested change

	className == null ? "" : className, methodName, fileName, Integer.parseInt(lineNumber));
	className ?? "", methodName, fileName, Integer.parseInt(lineNumber));

[collinjackson]

Oops, never mind, this is Java not Dart :)

[rmtmckenzie]

Unless you know something I don't, I don't think that Java has a null coalescing operator yet... (oops, for some reason github didn't show me your second comment until after I wrote this)

[rmtmckenzie]

But I agree that's definitely more readable 😄