feat(queryBuilder): remove aux queries for unrefined facets (#152)

Author: dhayab

helper/lib/src/query_builder.dart

@@ -17,10 +17,16 @@ final class QueryBuilder {
   /// Number of search result queries
   int get _resultQueriesCount => 1;
 
-  /// Number of generated disjunctive queries for given hierarchical
-  /// filters list
-  int get _disjunctiveQueriesCount =>
-      _searchState.disjunctiveFacets?.length ?? 0;
+  /// Number of generated disjunctive queries for given filters list
+  int get _disjunctiveQueriesCount => _getRefinedDisjunctiveFacets().length;
+
+  /// Get refined disjunctive facets from the search state's filter groups.
+  Iterable<String> _getRefinedDisjunctiveFacets() {
+    final currentFilterGroups = _searchState.filterGroups ?? {};
+    return (_searchState.disjunctiveFacets ?? {}).where((facetName) =>
+        currentFilterGroups.any(
+            (group) => group.any((facet) => facet.attribute == facetName)));
+  }
 
   /// Number of generated hierarchical queries for given hierarchical
   /// filters list
@@ -92,35 +98,35 @@ final class QueryBuilder {
 
   /// Build additional queries to fetch correct facets count values
   /// for disjunctive facets
-  Iterable<SearchState> _buildDisjunctiveFacetingQueries(SearchState query) =>
-      query.disjunctiveFacets?.map((facet) {
-        final filterGroupsCopy = <FilterGroup>{};
-        final currentFilterGroups = _searchState.filterGroups ?? {};
-        for (final filterGroup in currentFilterGroups) {
-          final Set<Filter> updatedFilters;
-          if (filterGroup.groupID.operator == FilterOperator.or) {
-            updatedFilters = filterGroup
-                .where(
-                  (element) =>
-                      !(element is FilterFacet && element.attribute == facet),
-                )
-                .toSet();
-          } else {
-            updatedFilters = filterGroup;
-          }
-          filterGroupsCopy.add(filterGroup.copyWith(filters: updatedFilters));
+  Iterable<SearchState> _buildDisjunctiveFacetingQueries(SearchState query) {
+    final currentFilterGroups = _searchState.filterGroups ?? {};
+    return _getRefinedDisjunctiveFacets().map((facet) {
+      final filterGroupsCopy = <FilterGroup>{};
+      for (final filterGroup in currentFilterGroups) {
+        final Set<Filter> updatedFilters;
+        if (filterGroup.groupID.operator == FilterOperator.or) {
+          updatedFilters = filterGroup
+              .where(
+                (element) =>
+                    !(element is FilterFacet && element.attribute == facet),
+              )
+              .toSet();
+        } else {
+          updatedFilters = filterGroup;
         }
-        return query.copyWith(
-          facets: [facet],
-          filterGroups: filterGroupsCopy,
-          attributesToRetrieve: ['objectID'],
-          // TODO: should be [], workaround to avoid the client exception
-          attributesToHighlight: ['objectID'],
-          hitsPerPage: 0,
-          analytics: false,
-        );
-      }) ??
-      [];
+        filterGroupsCopy.add(filterGroup.copyWith(filters: updatedFilters));
+      }
+      return query.copyWith(
+        facets: [facet],
+        filterGroups: filterGroupsCopy,
+        attributesToRetrieve: ['objectID'],
+        // TODO: should be [], workaround to avoid the client exception
+        attributesToHighlight: ['objectID'],
+        hitsPerPage: 0,
+        analytics: false,
+      );
+    });
+  }
 
   /// Create modifiable copy of filter groups.
   Set<FilterGroup> _copyFilterGroups() =>

helper/test/query_builder_test.dart

@@ -16,10 +16,33 @@ void main() {
     const queryBuilder = QueryBuilder(query);
     final queries = queryBuilder.build();
     final disjunctiveFacetingQueries = queries.skip(1);
-    expect(disjunctiveFacetingQueries.length, 2);
-    for (final query in disjunctiveFacetingQueries) {
-      expect(query.facets?.length, 1);
-    }
+    expect(disjunctiveFacetingQueries.length, 0);
+  });
+
+  test('test disjunctive faceting queries with some unrefined facets', () {
+    final filterGroups = <FilterGroup>{
+      FacetFilterGroup(FilterGroupID.or('g1'), {
+        Filter.facet('brand', 'samsung'),
+        Filter.facet('price', 100),
+      }),
+      FacetFilterGroup(FilterGroupID.or('g2'), {
+        Filter.facet('color', 'red'),
+      }),
+    };
+    final query = SearchState(
+      indexName: 'index',
+      query: 'phone',
+      disjunctiveFacets: {'brand', 'category', 'color', 'price'},
+      filterGroups: filterGroups,
+    );
+    final queryBuilder = QueryBuilder(query);
+    final queries = queryBuilder.build();
+    final disjunctiveFacetingQueries = queries.skip(1);
+    expect(disjunctiveFacetingQueries.length, 3);
+
+    final hasCategory = disjunctiveFacetingQueries
+        .any((query) => (query.facets ?? []).contains('category'));
+    expect(hasCategory, false);
   });
 
   test('test disjunctive faceting queries generation with filters', () {
@@ -236,6 +259,14 @@ void main() {
       query: 'phone',
       disjunctiveFacets: {'color', 'brand', 'size'},
       filterGroups: {
+        FacetFilterGroup(
+          FilterGroupID.or('g1'),
+          {
+            Filter.facet('color', 'blue'),
+            Filter.facet('brand', 'samsung'),
+            Filter.facet('size', 'l'),
+          },
+        ),
         FilterGroup.hierarchical(
           name: 'category',
           filters: {Filter.facet('category.lvl2', 'a > b > c')},