From b23ab153c86c8724edfb341fce680f5a38004162 Mon Sep 17 00:00:00 2001
From: Madeesh Kannan <shadeMe@users.noreply.github.com>
Date: Mon, 15 Jul 2024 17:13:15 +0200
Subject: [PATCH] fix: `OpenSearch` - Fallback to default filter policy when
 deserializing retrievers without the init parameter (#895)

---
 .../retrievers/opensearch/bm25_retriever.py   |  6 +++++-
 .../opensearch/embedding_retriever.py         |  6 +++++-
 .../opensearch/tests/test_bm25_retriever.py   | 19 +++++++++++++++++++
 .../tests/test_embedding_retriever.py         | 17 +++++++++++++++++
 4 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/bm25_retriever.py b/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/bm25_retriever.py
index 64aa57499..06a7afe85 100644
--- a/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/bm25_retriever.py
+++ b/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/bm25_retriever.py
@@ -119,7 +119,11 @@ def from_dict(cls, data: Dict[str, Any]) -> "OpenSearchBM25Retriever":
         data["init_parameters"]["document_store"] = OpenSearchDocumentStore.from_dict(
             data["init_parameters"]["document_store"]
         )
-        data["init_parameters"]["filter_policy"] = FilterPolicy.from_str(data["init_parameters"]["filter_policy"])
+
+        # Pipelines serialized with old versions of the component might not
+        # have the filter_policy field.
+        if "filter_policy" in data["init_parameters"]:
+            data["init_parameters"]["filter_policy"] = FilterPolicy.from_str(data["init_parameters"]["filter_policy"])
         return default_from_dict(cls, data)
 
     @component.output_types(documents=List[Document])
diff --git a/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/embedding_retriever.py b/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/embedding_retriever.py
index 08afce44b..eba5596f2 100644
--- a/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/embedding_retriever.py
+++ b/integrations/opensearch/src/haystack_integrations/components/retrievers/opensearch/embedding_retriever.py
@@ -118,7 +118,11 @@ def from_dict(cls, data: Dict[str, Any]) -> "OpenSearchEmbeddingRetriever":
         data["init_parameters"]["document_store"] = OpenSearchDocumentStore.from_dict(
             data["init_parameters"]["document_store"]
         )
-        data["init_parameters"]["filter_policy"] = FilterPolicy.from_str(data["init_parameters"]["filter_policy"])
+
+        # Pipelines serialized with old versions of the component might not
+        # have the filter_policy field.
+        if "filter_policy" in data["init_parameters"]:
+            data["init_parameters"]["filter_policy"] = FilterPolicy.from_str(data["init_parameters"]["filter_policy"])
         return default_from_dict(cls, data)
 
     @component.output_types(documents=List[Document])
diff --git a/integrations/opensearch/tests/test_bm25_retriever.py b/integrations/opensearch/tests/test_bm25_retriever.py
index 63d69b881..1cce2961c 100644
--- a/integrations/opensearch/tests/test_bm25_retriever.py
+++ b/integrations/opensearch/tests/test_bm25_retriever.py
@@ -96,6 +96,25 @@ def test_from_dict(_mock_opensearch_client):
     assert retriever._custom_query == {"some": "custom query"}
     assert retriever._raise_on_failure is False
 
+    # For backwards compatibility with older versions of the retriever without a filter policy
+    data = {
+        "type": "haystack_integrations.components.retrievers.opensearch.bm25_retriever.OpenSearchBM25Retriever",
+        "init_parameters": {
+            "document_store": {
+                "init_parameters": {"hosts": "some fake host", "index": "default"},
+                "type": "haystack_integrations.document_stores.opensearch.document_store.OpenSearchDocumentStore",
+            },
+            "filters": {},
+            "fuzziness": "AUTO",
+            "top_k": 10,
+            "scale_score": True,
+            "custom_query": {"some": "custom query"},
+            "raise_on_failure": False,
+        },
+    }
+    retriever = OpenSearchBM25Retriever.from_dict(data)
+    assert retriever._filter_policy == FilterPolicy.REPLACE
+
 
 def test_run():
     mock_store = Mock(spec=OpenSearchDocumentStore)
diff --git a/integrations/opensearch/tests/test_embedding_retriever.py b/integrations/opensearch/tests/test_embedding_retriever.py
index cf5a5dded..38be08698 100644
--- a/integrations/opensearch/tests/test_embedding_retriever.py
+++ b/integrations/opensearch/tests/test_embedding_retriever.py
@@ -106,6 +106,23 @@ def test_from_dict(_mock_opensearch_client):
     assert retriever._raise_on_failure is False
     assert retriever._filter_policy == FilterPolicy.REPLACE
 
+    # For backwards compatibility with older versions of the retriever without a filter policy
+    data = {
+        "type": type_s,
+        "init_parameters": {
+            "document_store": {
+                "init_parameters": {"hosts": "some fake host", "index": "default"},
+                "type": "haystack_integrations.document_stores.opensearch.document_store.OpenSearchDocumentStore",
+            },
+            "filters": {},
+            "top_k": 10,
+            "custom_query": {"some": "custom query"},
+            "raise_on_failure": False,
+        },
+    }
+    retriever = OpenSearchEmbeddingRetriever.from_dict(data)
+    assert retriever._filter_policy == FilterPolicy.REPLACE
+
 
 def test_run():
     mock_store = Mock(spec=OpenSearchDocumentStore)