Implement count_document for WeaviateDocumentStore (#267)

* Implement count_document for WeaviateDocumentStore

* Start container in test workflow

* Ditch Windows and Mac on Weaviate CI as Docker images are not provided

.github/workflows/weaviate.yml

@@ -29,15 +29,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        os: [ubuntu-latest]
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
 
     steps:
-      - name: Support longpaths
-        if: matrix.os == 'windows-latest'
-        working-directory: .
-        run: git config --system core.longpaths true
-
       - uses: actions/checkout@v4
 
       - name: Set up Python ${{ matrix.python-version }}
@@ -49,8 +44,10 @@ jobs:
         run: pip install --upgrade hatch
 
       - name: Lint
-        if: runner.os == 'Linux'
         run: hatch run lint:all
 
+      - name: Run Weaviate container
+        run: docker-compose up -d
+
       - name: Run tests
         run: hatch run cov

integrations/weaviate/src/haystack_integrations/document_stores/weaviate/document_store.py

@@ -188,7 +188,9 @@ def from_dict(cls, data: Dict[str, Any]) -> "WeaviateDocumentStore":
         )
 
     def count_documents(self) -> int:
-        return 0
+        collection_name = self._collection_settings["class"]
+        res = self._client.query.aggregate(collection_name).with_meta_count().do()
+        return res.get("data", {}).get("Aggregate", {}).get(collection_name, [{}])[0].get("meta", {}).get("count", 0)
 
     def filter_documents(self, filters: Optional[Dict[str, Any]] = None) -> List[Document]:  # noqa: ARG002
         return []

integrations/weaviate/tests/test_document_store.py

@@ -1,6 +1,7 @@
 from unittest.mock import MagicMock, patch
 
 import pytest
+from haystack.testing.document_store import CountDocumentsTest
 from haystack_integrations.document_stores.weaviate.document_store import (
     DOCUMENT_COLLECTION_PROPERTIES,
     WeaviateDocumentStore,
@@ -16,7 +17,7 @@
 )
 
 
-class TestWeaviateDocumentStore:
+class TestWeaviateDocumentStore(CountDocumentsTest):
     @pytest.fixture
     def document_store(self, request) -> WeaviateDocumentStore:
         # Use a different index for each test so we can run them in parallel
@@ -197,3 +198,7 @@ def test_from_dict(self, _mock_weaviate):
         assert document_store._additional_config.grpc_port_experimental == 12345
         assert document_store._additional_config.connection_config.session_pool_connections == 20
         assert document_store._additional_config.connection_config.session_pool_maxsize == 20
+
+    def test_count_not_empty(self, document_store):
+        # Skipped for the time being as we don't support writing documents
+        pass