forceOnAll will catch exception from resolving Stream element #39
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A little bit unfortunate and assuming, but it is existing behavior and must be preserved to avoid breaking stuff.
This enables mock usage validation by Mockito.
Behavior introduced in b4e2b41
runeflobakk
deleted the
catch-exception-from-resolving-stream-element
branch
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The expectation from forceOnAll is to force an attempt of execution of an operation on all elements. This works as intended when the elements are already resolved, as they are when passed as an array. But a
Streammay resolve it's elements from any source, also sources which can typically fail, e.g. if the element are sourced from an API request. By default, an exception occurring when the Stream tries to yield an element for the pipeline of filters, maps, etc, will abort the Stream terminal operation, and be immediately thrown.In order to "tap into" the resolving logic, the approach of flatmapping to a (potential) exception using the regular Stream API has now been replaced with a bit more "low-level" use of a Spliterator which will invoke the intended side-effect, and catch any exception which can happen for both trying to advance to the next element, and from the operation itself on wishes to execute on a successfully resolved element.
This subtly changes the behavior of
forceOnAll, but I consider this an alignment to what one expects fromforceOnAll.I also added
DiggStreams.describeCharacteristicsto get a String description of the characteristics of a Spliterator, which is represented as a bit-string, and difficult to resolve which actual characteristics are enabled. It is not used by any other code in Digg, but was useful when implementing/debugging theFlatMapToExceptionSpliterator, so I decided to include it. It does what it says on the tin, yields a text description, and you should not rely on the String for anything other than information.