Follow review comments

e2e_tests/conftest.py

@@ -6,11 +6,6 @@ from optuna_dashboard import wsgi
 import pytest
 
 
-@pytest.fixture(scope="session")
-def port() -> int:
-    return 8081
-
-
 @pytest.fixture(scope="session")
 def dummy_storage() -> optuna.storages.InMemoryStorage:
     storage = optuna.storages.InMemoryStorage()
@@ -183,11 +178,13 @@ def dummy_storage() -> optuna.storages.InMemoryStorage:
 
 
 @pytest.fixture(scope="session")
-def server(
-    request: pytest.FixtureRequest, dummy_storage: optuna.storages.InMemoryStorage, port: int
-) -> None:
+def server_url(
+    request: pytest.FixtureRequest, dummy_storage: optuna.storages.InMemoryStorage
+) -> str:
+    ip = "127.0.0.1"
+    port = 38080
     app = wsgi(dummy_storage)
-    httpd = make_server("127.0.0.1", port, app)
+    httpd = make_server(ip, port, app)
     thread = threading.Thread(target=httpd.serve_forever)
     thread.start()
 
@@ -197,3 +194,5 @@ def server(
         thread.join()
 
     request.addfinalizer(stop_server)
+
+    return f"http://{ip}:{port}/dashboard/"

e2e_tests/visual_regression_test.py

@@ -8,17 +8,15 @@ def test_study_list(
     study_id: int,
     page: Page,
     dummy_storage: optuna.storages.InMemoryStorage,
-    port: int,
-    server: None,
+    server_url: str,
 ) -> None:
     page.set_viewport_size({"width": 1000, "height": 3000})
-    url = f"http://localhost:{port}/dashboard/"
 
     summaries = optuna.get_all_study_summaries(dummy_storage)
     study_ids = {s._study_id: s.study_name for s in summaries}
 
     study_name = study_ids[study_id]
-    page.goto(url)
+    page.goto(server_url)
     page.click(f"a[href='/dashboard/studies/{study_id}']")
 
     element = page.query_selector(".MuiTypography-body1")