commit 18abad17ba1ce030bed401e1155fb743484f52e1
author Nasser Grainawi <nasser.grainawi@linaro.org> Thu Jan 19 10:24:09 2023 -0700
committer Nasser Grainawi <nasser.grainawi@linaro.org> Tue Jan 24 12:23:33 2023 -0700
tree 27ba99a274f7068d108993c84a30f02cf8e5828e
parent e72f8da257b7433a159d5761fab50bb4a58f7f2e

Fix negated label: queries with external groups

The ChangeIndexPostFilterPredicate approach doesn't fix the case where
the operator is also negated. For example if there was a query like
`status:open NOT label:Code-Review=1,group=ldap/testers` then in that
scenario we tried to index match Code-Review+1 votes and expected that
we would use post-filtering for the group. However, since the operator
was negated, we excluded those changes from the results before we
reached the post-filter stage, meaning we never include changes where
the voter isn't in the given group.

This solution is an unoptimized approach that avoids using the index for
the label operator whenever an external group is given. A better
approach would fix the negation case for any
ChangeIndexPostFilterPredicate, but that looks to be much more
complicated to implement.

Avoiding duplicated code is tricky here since the PostFilter and Index
predicates need to extend different classes, but share almost all of the
same logic for match(). Using a static inner helper class 'Matcher'
as a member of both the PostFilter and Index classes seems to be the
simplest way to minimize the duplication. Additionally we can extend
that helper class in each of the PostFilter/Index classes within
MagicLabelPredicates because they need slightly different behavior for
one method.

The added tests pass with both the Lucene and FakeIndex implementations,
but the FakeIndex also passes without the fix because it uses match()
instead of doing some kind of index search operation.

Release-Notes: Fixed bug with negated label: operator using an external group
Change-Id: I0268476f0e6e3008d30ce49dfbb71ea3b093f7c1