feat(app): 展示真实点赞与评论计数

test/comment/comment_controller_test.dart

@@ -42,6 +42,27 @@ void main() {
     model.dispose();
   });
 
+  test('should_expose_exact_count_only_when_last_page_is_loaded', () async {
+    final repository = FakeCommentRepository(
+      pages: [
+        CommentPage(
+          comments: [commentFixture(id: '2')],
+          nextCursor: '2',
+          hasMore: true,
+        ),
+        CommentPage(comments: [commentFixture(id: '1')]),
+      ],
+    );
+    final model = controller(repository);
+
+    await model.load();
+    expect(model.exactCount, isNull);
+
+    await model.loadMore();
+    expect(model.exactCount, 2);
+    model.dispose();
+  });
+
   test('should_use_server_content_and_pending_status_when_review_is_returned', () async {
     final repository = FakeCommentRepository(
       publishResult: commentFixture(