[Facet] Facet coverage rate not taken into account on the category page

[trivallain]

On the category page, all facets are display, even attributes with only 10% of coverage rate (Facet coverage rate parameters to 90).

Preconditions

Magento Version : 2.2.5 EE
ElasticSuite Version : 2.5.15
Environment : Developer mode

Steps to reproduce

1. Add several products to a category
2. Set black value to color attribute's on only one product

Expected result

1. Color facet is not display

Actual result

1. Color facet is display

vendor/smile/elasticsuite/src/module-elasticsuite-catalog/Model/Layer/RelevantFilterList.php
$coverageRates = $this->getCoverageRates($productCollection);
In $coverageRates, all the attributes value are set to 100.

[romainruaud]

Hello @trivallain

How are your indexes configured ? Can you check how the products look like in the Elasticsearch index directly ?

Regards

[romainruaud]

Ok, so we probably found what is responsible of this one during a live coding session :

• products are having a null value for the color attribute.

null values are removed by this line when preparing them : https://github.com/Smile-SA/elasticsuite/blob/master/src/module-elasticsuite-catalog/Model/Product/Indexer/Fulltext/Datasource/AttributeData.php#L91

BUT, on this next line, we keep adding the attribute_code into the special indexed_attributes field which is used for computing coverage : https://github.com/Smile-SA/elasticsuite/blob/master/src/module-elasticsuite-catalog/Model/Product/Indexer/Fulltext/Datasource/AttributeData.php#L101

This leads to having a product in the index without the color field, but having it inside indexed_attributes.

So, for now, a quick workaround is to prevent/remove these null values in the DB, which should be enough to have correct coverage.

By our side, we'll ensure being more restrictive with the data we put into the indexed_attributes field for indexing.