diff --git a/tests/test_reports.py b/tests/test_reports.py
index 3b4ef35..5a1deef 100644
--- a/tests/test_reports.py
+++ b/tests/test_reports.py
@@ -125,3 +125,36 @@ def test_generate_interval_domain_filter(tmp_path, sample_reports, monkeypatch):
         (tmp_path / "output" / "domains" / "example.com" / "hourly" / "hits.json").read_text()
     )
     assert hits[0]["value"] == 2
+
+
+def test_generate_root_index(tmp_path, sample_reports, monkeypatch):
+    db_path = tmp_path / "database" / "ngxstat.db"
+    setup_db(db_path)
+
+    monkeypatch.setattr(gr, "DB_PATH", db_path)
+    monkeypatch.setattr(gr, "OUTPUT_DIR", tmp_path / "output")
+    monkeypatch.setattr(gr, "REPORT_CONFIG", sample_reports)
+    monkeypatch.setattr(
+        gr, "TEMPLATE_DIR", Path(__file__).resolve().parents[1] / "templates"
+    )
+
+    gr._generate_interval("hourly")
+    gr._generate_interval("daily")
+
+    # create dummy domain directories
+    (tmp_path / "output" / "domains" / "foo.com").mkdir(parents=True)
+    (tmp_path / "output" / "domains" / "bar.com").mkdir(parents=True)
+
+    gr._generate_root_index()
+
+    index_file = tmp_path / "output" / "index.html"
+    assert index_file.exists()
+    content = index_file.read_text()
+
+    # check for interval links
+    assert 'data-interval="hourly"' in content
+    assert 'data-interval="daily"' in content
+
+    # check for domain links
+    assert 'data-domain="foo.com"' in content
+    assert 'data-domain="bar.com"' in content