feat(facets): when * is present, only send that parameter (#874)

* feat(facets): add expandWildcardFacets parameter to process * in facets

When * is present in facets, we don't need to request the individual facet values of each facet that's declared, as * will already request it.

With a new parameter "expandWildcardFacets", we filter out all facets that aren't * itself or -something. The new parameter doesn't add "*" automatically, it still

To decide:
- is "-something" worth caring about?
- when * isn't present, should no facets be requested or the default ones?
- is this the right location, maybe the client cache should have similar logic instead?

see: https://github.com/algolia/algoliasearch-helper-js/issues/391

* remove reference to non-existing -

* don't inject *

* rephrase

* remove the parameter, by default!

* Update src/requestBuilder.js

* fix

* Update test/spec/requestBuilder.js

Co-authored-by: François Chalifour <francoischalifour@users.noreply.github.com>

Co-authored-by: François Chalifour <francoischalifour@users.noreply.github.com>

index.d.ts

@@ -523,14 +523,16 @@ declare namespace algoliasearchHelper {
   export class SearchParameters implements PlainSearchParameters {
     managedParameters: [
       'index',
+
       'facets',
       'disjunctiveFacets',
       'facetsRefinements',
+      'hierarchicalFacets',
       'facetsExcludes',
+
       'disjunctiveFacetsRefinements',
       'numericRefinements',
       'tagRefinements',
-      'hierarchicalFacets',
       'hierarchicalFacetsRefinements'
     ];
 

src/SearchParameters/index.js

@@ -1312,9 +1312,17 @@ SearchParameters.prototype = {
 
   managedParameters: [
     'index',
-    'facets', 'disjunctiveFacets', 'facetsRefinements',
-    'facetsExcludes', 'disjunctiveFacetsRefinements',
-    'numericRefinements', 'tagRefinements', 'hierarchicalFacets', 'hierarchicalFacetsRefinements'
+
+    'facets',
+    'disjunctiveFacets',
+    'facetsRefinements',
+    'hierarchicalFacets',
+    'facetsExcludes',
+
+    'disjunctiveFacetsRefinements',
+    'numericRefinements',
+    'tagRefinements',
+    'hierarchicalFacetsRefinements'
   ],
   getQueryParams: function getQueryParams() {
     var managedParameters = this.managedParameters;

src/requestBuilder.js

@@ -60,7 +60,7 @@ var requestBuilder = {
     var numericFilters = requestBuilder._getNumericFilters(state);
     var tagFilters = requestBuilder._getTagFilters(state);
     var additionalParams = {
-      facets: facets,
+      facets: facets.indexOf('*') > -1 ? ['*'] : facets,
       tagFilters: tagFilters
     };
 

test/spec/requestBuilder.js

@@ -66,3 +66,64 @@ test('does only a single query if refinements are empty', function() {
   var queries = getQueries(searchParams.index, searchParams);
   expect(queries).toHaveLength(1);
 });
+
+describe('wildcard facets', function() {
+  test('keeps as-is if no * present', function() {
+    var searchParams = new SearchParameters({
+      facets: ['test'],
+      disjunctiveFacets: ['test_disjunctive', 'test_numeric'],
+      hierarchicalFacets: [{name: 'test_hierarchical', attributes: ['whatever']}]
+    });
+
+    var queries = getQueries(searchParams.index, searchParams);
+
+    expect(queries.length).toBe(1);
+    expect(queries[0].params.facets).toEqual([
+      'test',
+      'test_disjunctive',
+      'test_numeric',
+      'whatever'
+    ]);
+  });
+
+  test('keeps only *', function() {
+    var searchParams = new SearchParameters({
+      facets: ['test', '*'],
+      disjunctiveFacets: ['test_disjunctive', 'test_numeric'],
+      hierarchicalFacets: [{name: 'test_hierarchical', attributes: ['whatever']}]
+    });
+
+    var queries = getQueries(searchParams.index, searchParams);
+
+    expect(queries.length).toBe(1);
+    expect(queries[0].params.facets).toEqual(['*']);
+  });
+
+  test('keeps only * when first value', function() {
+    var searchParams = new SearchParameters({
+      facets: ['*', 'test'],
+      disjunctiveFacets: ['test_disjunctive', 'test_numeric'],
+      hierarchicalFacets: [{name: 'test_hierarchical', attributes: ['whatever']}]
+    });
+
+    var queries = getQueries(searchParams.index, searchParams);
+
+    expect(queries.length).toBe(1);
+    expect(queries[0].params.facets).toEqual(['*']);
+  });
+
+  test('only applies to first query', function() {
+    var searchParams = new SearchParameters({
+      facets: ['test', '*'],
+      disjunctiveFacets: ['test_disjunctive', 'test_numeric'],
+      hierarchicalFacets: [{name: 'test_hierarchical', attributes: ['whatever']}],
+      disjunctiveFacetsRefinements: {test_disjunctive: ['one', 'two']}
+    });
+
+    var queries = getQueries(searchParams.index, searchParams);
+
+    expect(queries.length).toBe(2);
+    expect(queries[0].params.facets).toEqual(['*']);
+    expect(queries[1].params.facets).toEqual('test_disjunctive');
+  });
+});