Improve type-checking

src/sidebar/store/modules/selection.js

@@ -531,16 +531,17 @@ function sortKeys(state) {
 /**
  * Retrieve state needed to calculate the root thread
  *
- * @return {ThreadState}
+ * @type {(rootState: any) => ThreadState}
  */
 const threadState = createSelector(
   rootState => rootState.annotations.annotations,
   rootState => rootState.route.name,
   rootState => rootState.selection,
   (annotations, routeName, selection) => {
-    const filters = {};
-    if (focusModeActive(selection)) {
-      filters.user = focusModeUserFilter(selection);
+    const filters = /** @type {Object.<string,string>} */ ({});
+    const userFilter = focusModeUserFilter(selection);
+    if (userFilter) {
+      filters.user = userFilter;
     }
     const selectionState = {
       expanded: expandedMap(selection),

src/sidebar/util/search-filter.js

@@ -134,7 +134,7 @@ export function toObject(searchText) {
  * Terms that are not associated with a particular facet are stored in the "any"
  * facet.
  *
- * @param {string|null} searchText - Filter query to parse
+ * @param {string} searchText - Filter query to parse
  * @param {FocusFilter} focusFilters - Additional filter terms to mix in
  * @return {Object.<string,Facet>}
  */

src/sidebar/util/thread-annotations.js

@@ -47,7 +47,7 @@ function buildRootThread(threadState) {
 
   if (annotationsFiltered) {
     const filters = generateFacetedFilter(
-      selection.filterQuery,
+      selection.filterQuery || '',
       selection.filters
     );
     options.filterFn = ann => filterAnnotations([ann], filters).length > 0;