Take into account the forced-visible set when filtering threads

When filtering annotations the `forcedVisible` list was taken into account, but
not when filtering threads. Consult this list when filtering threads as well.

This fixes an issue where newly created annotations would not be shown if they
did not match a thread filter. Note that newly added annotations are added to
the forced-visible set by the `ThreadList` component.

src/sidebar/helpers/build-thread.ts

@@ -317,7 +317,13 @@ export function buildThread(
     });
   } else if (options.threadFilterFn) {
     // Remove threads not matching thread-level filters
-    thread.children = thread.children.filter(options.threadFilterFn);
+    const threadFilterFn = options.threadFilterFn;
+    thread.children = thread.children.filter(thread => {
+      if (hasForcedVisible && options.forcedVisible.includes(thread.id)) {
+        return true;
+      }
+      return threadFilterFn(thread);
+    });
   }
 
   // Set visibility for threads.

src/sidebar/helpers/test/build-thread-test.js

@@ -475,18 +475,28 @@ describe('sidebar/helpers/build-thread', () => {
           text: 'note',
           target: [{ selector: undefined }],
         },
+        {
+          id: '3',
+          text: 'annotation',
+          target: [{ selector: undefined }],
+        },
       ];
 
-      it('shows only annotations matching the thread filter', () => {
+      it('shows only annotations matching the thread filter and forced-visible threads', () => {
         const thread = createThread(fixture, {
           threadFilterFn: thread => metadata.isPageNote(thread.annotation),
+          forcedVisible: ['3'],
         });
 
         assert.deepEqual(thread, [
           {
             annotation: fixture[1],
             children: [],
           },
+          {
+            annotation: fixture[2],
+            children: [],
+          },
         ]);
       });
     });