Using facets on numerical fields makes them disappear

Thanks for noting this! If nothing less it helped me understanding what my current problem is.

@tgoeg Thanks for reporting this.

I have added a draft MR that could be tested. The idea behind the solution/workaround is before indexing items, go through all the fields and for any numeric types add a duplicated field to the index with __facet__ prefix and a value converted to string. Then when generating facets we go through each one and check if any of them are numeric type - if they are run the facet query on meilisearch with prefixed __facet__ instead of the original one. At the end move those __facet__ results to the proper/original facet.

Patch can be tested but it is nowhere ready for merging or production, it is in mvp state and there are issues with filterableAttributes re-setting sometimes, losing the __facet__ prefixed attributes etc.

Can be tested by applying the patch, having a numeric field in the index and reindexing the entire index.

Hi and thanks for your quick patch!

It will take some time to check this, as I am currently buried in work with no end in sight, can @hexabinaer probably jump in for the time being?

I think the algorithm is legit and most likely a better approach as it keeps the numeric fields in their correct form and allows sorting, etc. and only converts to strings for the purpose of facetting, which I think should be OK for values with different digits.
This should definitely be tested, as I also had to workaround this problem recently as I had a numeric field indexed as string for faceting to work properly, but also wanted to use it to sort results. That didn't work out properly, as it was 0<value<100 and so the single digit values were sorted in the wrong way, i.e. alphanumerically, 9 > 80, which is not what visitors expect.
As you only add a numeric field for faceting, this should be cleaner.

When looking at the patch, this line jumped out:

-      $facetResults = $this->getFacetData($query->getIndex()->id(), array_keys($facets), [$filters], $keys);
+      $facetResults = $this->getFacetData($index, array_keys($facets), [$filters], $keys);

In all the other locations

$index=$query->getIndex()

but not

$index=$query->getIndex()->id()

You know I am no real dev so this might be totally OK, just wanted to mention it.