Add tests for `docs_src.dependencies.tutorial007`

tests/test_tutorial/test_dependencies/test_tutorial007.py

@@ -0,0 +1,24 @@
+import asyncio
+from contextlib import asynccontextmanager
+from unittest.mock import Mock, patch
+
+from docs_src.dependencies.tutorial007_py39 import get_db
+
+
+def test_get_db():  # Just for coverage
+    async def test_async_gen():
+        cm = asynccontextmanager(get_db)
+        async with cm() as db_session:
+            return db_session
+
+    dbsession_moock = Mock()
+
+    with patch(
+        "docs_src.dependencies.tutorial007_py39.DBSession",
+        return_value=dbsession_moock,
+        create=True,
+    ):
+        value = asyncio.run(test_async_gen())
+
+    assert value is dbsession_moock
+    dbsession_moock.close.assert_called_once()