add test for session.py (#118)

Author: yangm2

backend/pyproject.toml

@@ -26,6 +26,7 @@ build-backend = "setuptools.build_meta"
 dev = [
     "pytest>=8.3.5",
     "pytest-cov>=6.1.1",
+    "pytest-mock>=3.14.1",
     "ruff>=0.11.13",
     "ty>=0.0.1a8",
     "types-Flask>=1.1.6",

backend/tests/test_session.py

@@ -0,0 +1,54 @@
+import pytest
+from tenantfirstaid.session import TenantSession
+
+
+@pytest.fixture
+def mock_valkey(mocker):
+    """Mock the Valkey class with the db_con.ping(), db_con.get(), and db_con.set() methods."""
+    mock_client = mocker.Mock()
+    mocker.patch("tenantfirstaid.session.Valkey", return_value=mock_client)
+
+    _data = {}
+
+    mock_client.set = mocker.Mock(
+        side_effect=lambda key, value: _data.update({key: value})
+    )
+    mock_client.get = mocker.Mock(side_effect=lambda key: _data.get(key, None))
+    mock_client.ping = mocker.Mock()
+    return mock_client
+
+
+@pytest.fixture
+def mock_environ(monkeypatch):
+    monkeypatch.setenv("DB_HOST", "8.8.8.8")
+    monkeypatch.setenv("DB_PORT", "8888")
+    monkeypatch.setenv("DB_PASSWORD", "test_password")
+    monkeypatch.setenv("DB_USE_SSL", "false")
+
+
+def test_session_set_and_get(mock_valkey, mock_environ):
+    tenant_session = TenantSession()
+
+    mock_valkey.get.return_value = '"test_value"'
+    tenant_session.set("some_session_id", "test_value")
+    value = tenant_session.get("some_session_id")
+    assert value == "test_value"
+
+
+def test_session_get_unknown_session_id(mock_valkey, mock_environ):
+    tenant_session = TenantSession()
+
+    mock_valkey.get.return_value = None
+    value = tenant_session.get("some_session_id")
+    assert value == []
+
+
+def test_session_init_ping_exception(mocker, mock_environ, capsys):
+    # Patch Valkey so that ping raises an exception
+    mock_client = mocker.Mock()
+    mock_client.ping = mocker.Mock(side_effect=Exception("Ping failed"))
+    mocker.patch("tenantfirstaid.session.Valkey", return_value=mock_client)
+    # Should not raise, but print the exception
+    _obj = TenantSession()
+    captured = capsys.readouterr()
+    assert "Ping failed" in captured.out