Allow to run in strict mode. Fail if any exception is thrown while polling.

[jsalinaspolo]

Using PollingConditions might hide some errors while invoking the closure.

Adding a log.error might help to discover that an even that the test passed, an exception occurred.

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This change is 

[leonard84]

Hi, spock has no logging library at the moment, this is not an accident. Furthermore, you already get the error as the cause of the SpockException so I don't see a great gain here.

[jsalinaspolo]

Hi,
The reason was to avoid having to wrap the closure within a try/catch each time or to create our wrapper on PollingConditions.

If you do not see a gain, feel free to reject it. Might be a good reason to do not add logging.

[jsalinaspolo]

Having a second thought. You might have noticed that the SpockException is only thrown when the time elapsed times out.
If intermediate iterations fails with any exception then it will be hidden when an iteration success. In our case, we would like to know if have been any exception different than the assertion.

Instead of logging, would you prefer to have a config parameter to be unexceptional and fail the eventually if exceptions different than the assertion are thrown?

[leonard84]

Hm, having something akin to

spock/spock-core/src/main/java/spock/lang/Retry.java

Lines 47 to 54 in d751a0a

	/**
	* Configures which types of Exceptions should be retried.
	*
	* Subclasses are included if their parent class is listed.
	*
	* @return array of Exception classes to retry.
	*/
	Class<? extends Throwable>[] exceptions() default {Exception.class, AssertionError.class};

as property for PollingConditions would be ok.

Please be aware, that we won't merge anything until 2.0 branch is green.

[jsalinaspolo]

@leonard84 Let me know if you think that passing a parameter to run it on strict mode looks a good approach?