Hi Alistair.
I think the difference here is that in the playground 'self' is nil,
while in the browser 'self' is the class being inspected.
UndefinedObject>>handleSignal: tells the exception to execute its
#defaultAction, which is to signal the UnhandledError, and thus it
evaluates the block.
#handleSignal: is sent to contexts chain in the stack during error processing which ends up at top context and its nil sender. It is not related to the receiver of messages on the stack.
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One other thing to keep in mind, UnhandledError is a subclass of
Exception.��
That's correct. But it does not matter for my findings.
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It will only catch signals of itself, unlike Error or
Exception, which will catch all their subclasses.�� So 'MyTestError
signal' can only be caught if something catches it and then signals
UnhandledError.�� In this�� case it is the #defaultAction.
Yes, and here is the trick. When error resignals UnhandledError from the defaultAction it is caught by UnhandledError handler but only if there was no outer handler which already processed original error
HTH,
Alistair