Add load db test

e2e_tests/test_standalone/test_study_list.py

@@ -1,3 +1,6 @@
+import os
+import time
+
 from playwright.sync_api import Page
 import pytest
 
@@ -20,3 +23,38 @@ def test_home(
     title = element.text_content()
     assert title is not None
     assert title == "Optuna Dashboard (Wasm ver.)"
+
+
+def test_load_storage(
+    page: Page,
+    server_url: str,
+) -> None:
+    test_file = "e2etest.db"
+
+    if os.path.exists(f"./{test_file}"):
+        os.remove(f"./{test_file}")
+
+    def create_storage_file():
+        import optuna
+
+        storage = optuna.storages.RDBStorage(f"sqlite:///{test_file}")
+        study = optuna.create_study(study_name="single-objective", storage=storage)
+
+        def objective(trial: optuna.Trial) -> float:
+            x1 = trial.suggest_float("x1", 0, 10)
+            x2 = trial.suggest_float("x2", 0, 10)
+            x3 = trial.suggest_categorical("x3", ["foo", "bar"])
+            return (x1 - 2) ** 2 + (x2 - 5) ** 2
+
+        study.optimize(objective, n_trials=100)
+
+    create_storage_file()
+
+    url = f"{server_url}"
+    page.goto(url)
+    name = "Load an Optuna Storage Drag your SQLite3 file here or click to browse."
+    page.get_by_role("button", name=name).click()
+
+    time.sleep(1)
+    page.get_by_role("button", name=name).set_input_files(f"./{test_file}")
+    os.remove(f"./{test_file}")