I am writing a VoteResultFunction plugin for the module like and dislike → that calculates the total of likes substracting the number of dislikes. This module defines two vote types for liking and disliking so I access data from other votes types when calculating. The problem comes when the last vote from an entity is removed so all the calculations are deleted and since there is no more votes to calculate the result for that entity remains deleted in the votingapi_results table.
Recalculate votes for an entity with no votes.
Tally votes even for empty sets
Code it.
VoteResultFunction plugins can receive empty arrays.
When deleting the last vote of an entity the results will be calculated so for example the VoteResultFunction shipped with the module will store zeroes.
Needs work
4.0
Code
The change is currently missing an automated test that fails when run with the original code, and succeeds when the bug has been fixed.
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
MR needs to be rebased against 4.0.x. But it looks like a reasonable improvement on the code. The only thing I think needs to be added is a test to make sure the result functions work when there are no votes - your patch fixes that for the Average function, but if we add new functions in the future or if some dependent module adds some result functions, then we want to have this test to make sure those functions don't have the same problem.