feat: allow specifying search parameters in the URL

lms/static/js/discovery/discovery_factory.js

@@ -21,7 +21,23 @@
                 userLanguage: userLanguage,
                 userTimezone: userTimezone
             };
-            if (setDefaultFilter && userLanguage) {
+            // Read facet filters from URL query parameters and apply them.
+            var urlParams = new URLSearchParams(window.location.search);
+            urlParams.forEach(function(value, key) {
+                if (key === 'search_query') {
+                    return; // handled separately via the searchQuery argument
+                }
+                if (key in meanings) {
+                    filters.add({
+                        type: key,
+                        query: value,
+                        name: refineSidebar.termName(key, value)
+                    });
+                }
+            });
+
+            // Apply the default language filter, except when provided via URL parameters.
+            if (setDefaultFilter && userLanguage && !filters.get('language')) {
                 filters.add({
                     type: 'language',
                     query: userLanguage,
@@ -30,6 +46,20 @@
             }
             listing = new CoursesListing({model: courseListingModel});
 
+            function updateUrl() {
+                var params = new URLSearchParams();
+                filters.each(function(filter) {
+                    if (filter.id === 'search_query') {
+                        params.set('search_query', filter.get('query'));
+                    } else {
+                        params.set(filter.id, filter.get('query'));
+                    }
+                });
+                var qs = params.toString();
+                var newUrl = window.location.pathname + (qs ? '?' + qs : '');
+                history.replaceState(null, '', newUrl);
+            }
+
             dispatcher.listenTo(form, "search", function (query) {
                 form.showLoadingIndicator();
                 if (!query || query.trim() === "") {
@@ -79,6 +109,7 @@
                 form.hideLoadingIndicator();
                 listing.render();
                 refineSidebar.render();
+                updateUrl();
             });
 
             dispatcher.listenTo(search, 'error', function() {

lms/static/js/spec/discovery/discovery_factory_spec.js

@@ -225,4 +225,100 @@ define([
             expect(request.requestBody).toMatch(/language=en/);
         });
     });
+
+    describe('discovery.DiscoveryFactory URL sync', function() {
+        var originalSearch;
+        var replaceStateSpy;
+
+        function setUrlSearch(search) {
+            // Override window.location.search for the factory to read
+            originalSearch = window.location.search;
+            // Use history.replaceState to set query parameters without navigation
+            history.replaceState(null, '', window.location.pathname + search);
+        }
+
+        beforeEach(function() {
+            originalSearch = window.location.search;
+            replaceStateSpy = spyOn(history, 'replaceState').and.callThrough();
+            loadFixtures('js/fixtures/discovery.html');
+            TemplateHelpers.installTemplates([
+                'templates/discovery/course_card',
+                'templates/discovery/facet',
+                'templates/discovery/facet_option',
+                'templates/discovery/filter',
+                'templates/discovery/filter_bar'
+            ]);
+            jasmine.clock().install();
+        });
+
+        afterEach(function() {
+            jasmine.clock().uninstall();
+            // Restore original URL
+            history.replaceState(null, '', window.location.pathname + originalSearch);
+        });
+
+        it('pre-populates filters from URL query params', function() {
+            setUrlSearch('?modes=honor');
+            DiscoveryFactory(MEANINGS);
+
+            var requests = AjaxHelpers.requests(this);
+            $('.discovery-submit').trigger('click');
+            var request = AjaxHelpers.currentRequest(requests);
+            expect(request.requestBody).toMatch(/modes=honor/);
+            expect($('.active-filter').length).toBe(1);
+        });
+
+        it('overrides default language filter with URL param', function() {
+            // Set URL with language filter different from the default
+            setUrlSearch('?language=hr');
+            // Call DiscoveryFactory with userLanguage='en' and setDefaultFilter=true
+            DiscoveryFactory(MEANINGS, '', 'en', 'Europe/Lisbon', true);
+
+            var requests = AjaxHelpers.requests(this);
+            $('.discovery-submit').trigger('click');
+            var request = AjaxHelpers.currentRequest(requests);
+            expect(request.requestBody).toMatch(/language=hr/);
+            expect(request.requestBody).not.toMatch(/language=en/);
+        });
+
+        it('ignores unrecognized URL params', function() {
+            setUrlSearch('?bogus=value');
+            DiscoveryFactory(MEANINGS);
+
+            var requests = AjaxHelpers.requests(this);
+            $('.discovery-submit').trigger('click');
+            var request = AjaxHelpers.currentRequest(requests);
+            expect(request.requestBody).not.toMatch(/bogus/);
+            expect($('.active-filter').length).toBe(0);
+        });
+
+        it('updates URL after search completes', function() {
+            setUrlSearch('');
+            DiscoveryFactory(MEANINGS);
+
+            var requests = AjaxHelpers.requests(this);
+            $('.discovery-input').val('test');
+            $('.discovery-submit').trigger('click');
+            AjaxHelpers.respondWithJson(requests, JSON_RESPONSE);
+            expect(replaceStateSpy).toHaveBeenCalled();
+            var lastCall = replaceStateSpy.calls.mostRecent();
+            expect(lastCall.args[2]).toMatch(/search_query=test/);
+        });
+
+        it('clears URL params when filters are reset', function() {
+            setUrlSearch('?language=en');
+            DiscoveryFactory(MEANINGS);
+
+            var requests = AjaxHelpers.requests(this);
+            // Trigger initial search to load results
+            $('.discovery-submit').trigger('click');
+            AjaxHelpers.respondWithJson(requests, JSON_RESPONSE);
+            // Clear all filters
+            $('#clear-all-filters').trigger('click');
+            // The clear triggers a new search with empty query
+            AjaxHelpers.respondWithJson(requests, JSON_RESPONSE);
+            var lastCall = replaceStateSpy.calls.mostRecent();
+            expect(lastCall.args[2]).toBe(window.location.pathname);
+        });
+    });
 });