Add _store_name field to StoreAwareMixin to ease serialisation (#5531)

haystack/preview/document_stores/mixins.py

@@ -13,6 +13,10 @@ class StoreAwareMixin:
     """
 
     _store: Optional[Store] = None
+    # This is necessary to ease serialisation when converting a Component that uses
+    # a Store into a dictionary.
+    # This is only set when calling `Pipeline.add_component()`.
+    _store_name: str = ""
     supported_stores: List[Type[Store]]  # type: ignore # (see https://github.com/python/mypy/issues/4717)
 
     @property

haystack/preview/pipeline.py

@@ -99,6 +99,7 @@ class Pipeline(CanalsPipeline):
                 raise ValueError("Reusing components with stores is not supported (yet). Create a separate instance.")
 
             instance.store = self._stores[store]
+            instance._store_name = store
 
         elif store:
             raise ValueError(f"Component '{name}' doesn't support stores.")

test/preview/pipeline/test_pipeline.py

@@ -102,6 +102,7 @@ def test_add_component_store_aware_component_receives_one_docstore():
     pipe.add_store(name="second_store", store=store_2)
     pipe.add_component("component", mock, store="first_store")
     assert mock.store == store_1
+    assert mock._store_name == "first_store"
     assert pipe.run(data={"component": {"value": 1}}) == {"component": {"value": 1}}
 
 
@@ -188,6 +189,7 @@ def test_add_component_store_aware_component_receives_correct_docstore_type():
 
     pipe.add_component("component", mock, store="second_store")
     assert mock.store == store_2
+    assert mock._store_name == "second_store"
 
 
 @pytest.mark.unit
@@ -217,6 +219,7 @@ def test_add_component_store_aware_component_is_reused():
         pipe.add_component("component2", mock, store="first_store")
 
     assert mock.store == store_2
+    assert mock._store_name == "second_store"
 
 
 @pytest.mark.unit
@@ -243,8 +246,9 @@ def test_add_component_store_aware_component_receives_subclass_of_correct_docsto
 
     pipe.add_component("component", mock, store="first_store")
     assert mock.store == store_1
+    assert mock._store_name == "first_store"
     pipe.add_component("component2", mock2, store="second_store")
-    assert mock2.store == store_2
+    assert mock2._store_name == "second_store"
 
 
 @pytest.mark.unit