add test for default write documents behavior

tests/test_document_store.py

@@ -75,6 +75,19 @@ def test_comparison_equal_with_none(self, document_store, filterable_docs):
         # Astra does not support filtering on None, it returns empty list
         self.assert_documents_are_equal(result, [])
 
+    def test_write_documents(self, document_store: AstraDocumentStore):
+        """
+        Test write_documents() overwrites stored Document when trying to write one with same id
+        using DuplicatePolicy.OVERWRITE.
+        """
+        doc1 = Document(id="1", content="test doc 1")
+        doc2 = Document(id="1", content="test doc 2")
+
+        assert document_store.write_documents([doc2], policy=DuplicatePolicy.OVERWRITE) == 1
+        self.assert_documents_are_equal(document_store.filter_documents(), [doc2])
+        assert document_store.write_documents(documents=[doc1], policy=DuplicatePolicy.OVERWRITE) == 1
+        self.assert_documents_are_equal(document_store.filter_documents(), [doc1])
+
     def test_delete_documents_non_existing_document(self, document_store: AstraDocumentStore):
         """
         Test delete_documents() doesn't delete any Document when called with non existing id.