Add function get_value to BaseStorage (#1594)

* Add function `get_value` to all built-in storage implementations, `FSMContext` and `SceneWizard` (#1431)

* Fix type hints

* Split up return statements in `get_value` functions

* Implement `get_value` method in `BaseStorage` and remove redundant implementations

tests/test_fsm/storage/test_storages.py

@@ -22,11 +22,27 @@ class TestStorages:
 
     async def test_set_data(self, storage: BaseStorage, storage_key: StorageKey):
         assert await storage.get_data(key=storage_key) == {}
+        assert await storage.get_value(storage_key=storage_key, dict_key="foo") is None
+        assert (
+            await storage.get_value(storage_key=storage_key, dict_key="foo", default="baz")
+            == "baz"
+        )
 
         await storage.set_data(key=storage_key, data={"foo": "bar"})
         assert await storage.get_data(key=storage_key) == {"foo": "bar"}
+        assert await storage.get_value(storage_key=storage_key, dict_key="foo") == "bar"
+        assert (
+            await storage.get_value(storage_key=storage_key, dict_key="foo", default="baz")
+            == "bar"
+        )
+
         await storage.set_data(key=storage_key, data={})
         assert await storage.get_data(key=storage_key) == {}
+        assert await storage.get_value(storage_key=storage_key, dict_key="foo") is None
+        assert (
+            await storage.get_value(storage_key=storage_key, dict_key="foo", default="baz")
+            == "baz"
+        )
 
     async def test_update_data(self, storage: BaseStorage, storage_key: StorageKey):
         assert await storage.get_data(key=storage_key) == {}

tests/test_fsm/test_context.py

@@ -34,6 +34,10 @@ class TestFSMContext:
         assert await state2.get_data() == {}
         assert await state3.get_data() == {}
 
+        assert await state.get_value("foo") == "bar"
+        assert await state2.get_value("foo") is None
+        assert await state3.get_value("foo", "baz") == "baz"
+
         await state2.set_state("experiments")
         assert await state.get_state() == "test"
         assert await state3.get_state() is None

tests/test_fsm/test_scene.py

@@ -1004,6 +1004,24 @@ class TestSceneWizard:
 
         wizard.state.get_data.assert_called_once_with()
 
+    async def test_scene_wizard_get_value_with_default(self):
+        wizard = SceneWizard(
+            scene_config=AsyncMock(),
+            manager=AsyncMock(),
+            state=AsyncMock(),
+            update_type="message",
+            event=AsyncMock(),
+            data={},
+        )
+        args = ("test_key", "test_default")
+        value = "test_value"
+        wizard.state.get_value = AsyncMock(return_value=value)
+
+        result = await wizard.get_value(*args)
+        wizard.state.get_value.assert_called_once_with(*args)
+
+        assert result == value
+
     async def test_scene_wizard_update_data_if_data(self):
         wizard = SceneWizard(
             scene_config=AsyncMock(),