Product Query: Unify data structure for tax_query and meta_query

[dinhtungdu]

Is your feature request related to a problem? Please describe.

In Product Query, we're using different data structures for partial tax_query and meta_query objects:

In get_stock_status_query() and get_filter_by_price_query(), the meta_query key holds an array containing query data (key, value, compare).

woocommerce-blocks/src/BlockTypes/ProductQuery.php

Lines 258 to 266 in 9b79613

	private function get_stock_status_query( $stock_statii ) {
	return array(
	'meta_query' => array(
	'key' => '_stock_status',
	'value' => (array) $stock_statii,
	'compare' => 'IN',
	),
	);
	}

woocommerce-blocks/src/BlockTypes/ProductQuery.php

Lines 401 to 407 in 9b79613

	return array(
	'meta_query' => array(
	'relation' => 'AND',
	$max_price_query,
	$min_price_query,
	),
	);

Same for tax_query in get_filter_by_attributes_query():

woocommerce-blocks/src/BlockTypes/ProductQuery.php

Lines 450 to 455 in 9b79613

	return array(
	'tax_query' => array(
	'relation' => 'AND',
	$queries,
	),
	);

---

But in get_filter_by_stock_status_query(), the meta_query key holds an array containing a nested array which contains query data:

woocommerce-blocks/src/BlockTypes/ProductQuery.php

Lines 481 to 492 in 9b79613

	return array(
	// Ignoring the warning of not using meta queries.
	// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
	'meta_query' => array(
	array(
	'key' => '_stock_status',
	'value' => $filtered_stock_status_values,
	'operator' => 'IN',
	),
	),
	);

Describe the solution you'd like

We should unify the way we return tax_query and meta_query data. We could go either way but should use only one.

Additional context

This will be solved by #7697. I raise this issue to explain the reason for returned data changes in #7697. cc @gigitux @sunyatasattva

[sunyatasattva]

Correct me if I'm wrong here, but I think the odd one out is get_stock_status_query(), right? Because get_filter_by_price_query() contains the relationship key at the top level, but then has nested arrays, as it should be. Or am I missing the point here? I think the wrong one is get_filter_by_price_query() (which, incidentally, I wrote 😬 ) and we should fix and change that. I agree that we should have a consistent shape.

EDIT: Ok I checked #7697 and I understand what you mean with get_filter_by_price_query(). I agree with the approach you took there. We should however think about a top-level relationship key at some point. But that's more a design discussion.

[dinhtungdu]

We should however think about a top-level relationship key at some point. But that's more a design discussion.

I agree. For now, in #7697, we simply merge them, and each partial query (meta, date, tax) will be encapsulated inside an array.