tests: add unit tests for NetworkXStorage (#24)

* Added unittests and handling edge and node degree with non-existing node

* Added more test cases for community schema and stable largest connected component

---------

Co-authored-by: terence-gpt <numberchiffre@users.noreply.github.com>

Author: NumberChiffre

nano_graphrag/_storage.py

@@ -344,10 +344,12 @@ async def get_node(self, node_id: str) -> Union[dict, None]:
         return self._graph.nodes.get(node_id)
 
     async def node_degree(self, node_id: str) -> int:
-        return self._graph.degree(node_id)
+        # [numberchiffre]: node_id not part of graph returns `DegreeView({})` instead of 0
+        return self._graph.degree(node_id) if self._graph.has_node(node_id) else 0
 
     async def edge_degree(self, src_id: str, tgt_id: str) -> int:
-        return self._graph.degree(src_id) + self._graph.degree(tgt_id)
+        return (self._graph.degree(src_id) if self._graph.has_node(src_id) else 0) + \
+               (self._graph.degree(tgt_id) if self._graph.has_node(tgt_id) else 0)
 
     async def get_edge(
         self, source_node_id: str, target_node_id: str

tests/test_networkx_storage.py

@@ -0,0 +1,377 @@
+import os
+import shutil
+import pytest
+import networkx as nx
+import numpy as np
+import asyncio
+import json
+from nano_graphrag import GraphRAG
+from nano_graphrag._storage import NetworkXStorage
+from nano_graphrag._utils import wrap_embedding_func_with_attrs
+
+WORKING_DIR = "./tests/nano_graphrag_cache_networkx_storage_test"
+
+
+@pytest.fixture(scope="function")
+def setup_teardown():
+    if os.path.exists(WORKING_DIR):
+        shutil.rmtree(WORKING_DIR)
+    os.mkdir(WORKING_DIR)
+    
+    yield
+    
+    shutil.rmtree(WORKING_DIR)
+
+
+@wrap_embedding_func_with_attrs(embedding_dim=384, max_token_size=8192)
+async def mock_embedding(texts: list[str]) -> np.ndarray:
+    return np.random.rand(len(texts), 384)
+
+
+@pytest.fixture
+def networkx_storage(setup_teardown):
+    rag = GraphRAG(working_dir=WORKING_DIR, embedding_func=mock_embedding)
+    return NetworkXStorage(
+        namespace="test",
+        global_config=rag.__dict__,
+    )
+
+
+@pytest.mark.asyncio
+async def test_upsert_and_get_node(networkx_storage):
+    node_id = "node1"
+    node_data = {"attr1": "value1", "attr2": "value2"}
+    
+    await networkx_storage.upsert_node(node_id, node_data)
+    
+    result = await networkx_storage.get_node(node_id)
+    assert result == node_data
+    
+    has_node = await networkx_storage.has_node(node_id)
+    assert has_node is True
+
+
+@pytest.mark.asyncio
+async def test_upsert_and_get_edge(networkx_storage):
+    source_id = "node1"
+    target_id = "node2"
+    edge_data = {"weight": 1.0, "type": "connection"}
+    
+    await networkx_storage.upsert_node(source_id, {})
+    await networkx_storage.upsert_node(target_id, {})
+    await networkx_storage.upsert_edge(source_id, target_id, edge_data)
+    
+    result = await networkx_storage.get_edge(source_id, target_id)
+    assert result == edge_data
+    
+    has_edge = await networkx_storage.has_edge(source_id, target_id)
+    assert has_edge is True
+
+
+@pytest.mark.asyncio
+async def test_node_degree(networkx_storage):
+    node_id = "center"
+    await networkx_storage.upsert_node(node_id, {})
+    
+    num_neighbors = 5
+    for i in range(num_neighbors):
+        neighbor_id = f"neighbor{i}"
+        await networkx_storage.upsert_node(neighbor_id, {})
+        await networkx_storage.upsert_edge(node_id, neighbor_id, {})
+    
+    degree = await networkx_storage.node_degree(node_id)
+    assert degree == num_neighbors
+
+
+@pytest.mark.asyncio
+async def test_edge_degree(networkx_storage):
+    source_id = "node1"
+    target_id = "node2"
+    
+    await networkx_storage.upsert_node(source_id, {})
+    await networkx_storage.upsert_node(target_id, {})
+    await networkx_storage.upsert_edge(source_id, target_id, {})
+    
+    num_source_neighbors = 3
+    for i in range(num_source_neighbors):
+        neighbor_id = f"neighbor{i}"
+        await networkx_storage.upsert_node(neighbor_id, {})
+        await networkx_storage.upsert_edge(source_id, neighbor_id, {})
+    
+    num_target_neighbors = 2
+    for i in range(num_target_neighbors):
+        neighbor_id = f"target_neighbor{i}"
+        await networkx_storage.upsert_node(neighbor_id, {})
+        await networkx_storage.upsert_edge(target_id, neighbor_id, {})
+    
+    expected_edge_degree = (num_source_neighbors + 1) + (num_target_neighbors + 1)
+    edge_degree = await networkx_storage.edge_degree(source_id, target_id)
+    assert edge_degree == expected_edge_degree
+
+
+@pytest.mark.asyncio
+async def test_get_node_edges(networkx_storage):
+    center_id = "center"
+    await networkx_storage.upsert_node(center_id, {})
+    
+    expected_edges = []
+    for i in range(3):
+        neighbor_id = f"neighbor{i}"
+        await networkx_storage.upsert_node(neighbor_id, {})
+        await networkx_storage.upsert_edge(center_id, neighbor_id, {})
+        expected_edges.append((center_id, neighbor_id))
+    
+    result = await networkx_storage.get_node_edges(center_id)
+    assert set(result) == set(expected_edges)
+
+
+@pytest.mark.parametrize("algorithm", ["leiden"])
+@pytest.mark.asyncio
+async def test_clustering(networkx_storage, algorithm):
+    # [numberchiffre]: node ID is case-sensitive for clustering with leiden.
+    for i in range(10):
+        await networkx_storage.upsert_node(f"NODE{i}", {"source_id": f"chunk{i}"})
+    
+    for i in range(9):
+        await networkx_storage.upsert_edge(f"NODE{i}", f"NODE{i+1}", {})
+    
+    assert networkx_storage._graph.number_of_nodes() > 0
+    assert networkx_storage._graph.number_of_edges() > 0
+    await networkx_storage.clustering(algorithm=algorithm)
+    
+    community_schema = await networkx_storage.community_schema()
+
+    assert len(community_schema) > 0
+    
+    for community in community_schema.values():
+        assert "level" in community
+        assert "title" in community
+        assert "edges" in community
+        assert "nodes" in community
+        assert "chunk_ids" in community
+        assert "occurrence" in community
+        assert "sub_communities" in community
+
+
+@pytest.mark.parametrize("algorithm", ["leiden"])
+@pytest.mark.asyncio
+async def test_leiden_clustering_consistency(networkx_storage, algorithm):
+    for i in range(10):
+        await networkx_storage.upsert_node(f"NODE{i}", {"source_id": f"chunk{i}"})
+    for i in range(9):
+        await networkx_storage.upsert_edge(f"NODE{i}", f"NODE{i+1}", {})
+    
+    results = []
+    for _ in range(3):
+        await networkx_storage.clustering(algorithm=algorithm)
+        community_schema = await networkx_storage.community_schema()
+        results.append(community_schema)
+    
+    assert all(len(r) == len(results[0]) for r in results), "Number of communities should be consistent"
+
+
+@pytest.mark.parametrize("algorithm", ["leiden"])
+@pytest.mark.asyncio
+async def test_leiden_clustering_community_structure(networkx_storage, algorithm):
+    for i in range(10):
+        await networkx_storage.upsert_node(f"A{i}", {"source_id": f"chunkA{i}"})
+        await networkx_storage.upsert_node(f"B{i}", {"source_id": f"chunkB{i}"})
+    for i in range(9):
+        await networkx_storage.upsert_edge(f"A{i}", f"A{i+1}", {})
+        await networkx_storage.upsert_edge(f"B{i}", f"B{i+1}", {})
+    
+    await networkx_storage.clustering(algorithm=algorithm)
+    community_schema = await networkx_storage.community_schema()
+    
+    assert len(community_schema) >= 2, "Should have at least two communities"
+    
+    communities = list(community_schema.values())
+    a_nodes = set(node for node in communities[0]['nodes'] if node.startswith('A'))
+    b_nodes = set(node for node in communities[0]['nodes'] if node.startswith('B'))
+    assert len(a_nodes) == 0 or len(b_nodes) == 0, "Nodes from different groups should be in different communities"
+
+
+@pytest.mark.parametrize("algorithm", ["leiden"])
+@pytest.mark.asyncio
+async def test_leiden_clustering_hierarchical_structure(networkx_storage, algorithm):
+    await networkx_storage.upsert_node("NODE1", {"source_id": "chunk1", "clusters": json.dumps([{"level": 0, "cluster": "0"}, {"level": 1, "cluster": "1"}])})
+    await networkx_storage.upsert_node("NODE2", {"source_id": "chunk2", "clusters": json.dumps([{"level": 0, "cluster": "0"}, {"level": 1, "cluster": "2"}])})
+    await networkx_storage.upsert_edge("NODE1", "NODE2", {})
+    await networkx_storage.clustering(algorithm=algorithm)
+    community_schema = await networkx_storage.community_schema()
+    
+    levels = set(community['level'] for community in community_schema.values())
+    assert len(levels) >= 1, "Should have at least one level in the hierarchy"
+    
+    communities_per_level = {level: sum(1 for c in community_schema.values() if c['level'] == level) for level in levels}
+    assert communities_per_level[0] >= communities_per_level.get(max(levels), 0), "Lower levels should have more or equal number of communities"
+
+
+@pytest.mark.asyncio
+async def test_persistence(setup_teardown):
+    rag = GraphRAG(working_dir=WORKING_DIR, embedding_func=mock_embedding)
+    initial_storage = NetworkXStorage(
+        namespace="test_persistence",
+        global_config=rag.__dict__,
+    )
+    
+    await initial_storage.upsert_node("node1", {"attr": "value"})
+    await initial_storage.upsert_node("node2", {"attr": "value"})
+    await initial_storage.upsert_edge("node1", "node2", {"weight": 1.0})
+    
+    await initial_storage.index_done_callback()
+    
+    new_storage = NetworkXStorage(
+        namespace="test_persistence",
+        global_config=rag.__dict__,
+    )
+    
+    assert await new_storage.has_node("node1")
+    assert await new_storage.has_node("node2")
+    assert await new_storage.has_edge("node1", "node2")
+    
+    node1_data = await new_storage.get_node("node1")
+    assert node1_data == {"attr": "value"}
+    
+    edge_data = await new_storage.get_edge("node1", "node2")
+    assert edge_data == {"weight": 1.0}
+
+
+@pytest.mark.asyncio
+async def test_embed_nodes(networkx_storage):
+    for i in range(5):
+        await networkx_storage.upsert_node(f"node{i}", {"id": f"node{i}"})
+    
+    for i in range(4):
+        await networkx_storage.upsert_edge(f"node{i}", f"node{i+1}", {})
+    
+    embeddings, node_ids = await networkx_storage.embed_nodes("node2vec")
+    
+    assert embeddings.shape == (5, networkx_storage.global_config['node2vec_params']['dimensions'])
+    assert len(node_ids) == 5
+    assert all(f"node{i}" in node_ids for i in range(5))
+
+
+@pytest.mark.asyncio
+async def test_stable_largest_connected_component_equal_components():
+    G = nx.Graph()
+    G.add_edges_from([("A", "B"), ("C", "D"), ("E", "F")])
+    result = NetworkXStorage.stable_largest_connected_component(G)
+    assert sorted(result.nodes()) == ["A", "B"]
+    assert list(result.edges()) == [("A", "B")]
+
+
+@pytest.mark.asyncio
+async def test_stable_largest_connected_component_stability():
+    G = nx.Graph()
+    G.add_edges_from([("A", "B"), ("B", "C"), ("C", "D"), ("E", "F")])
+    result1 = NetworkXStorage.stable_largest_connected_component(G)
+    result2 = NetworkXStorage.stable_largest_connected_component(G)
+    assert nx.is_isomorphic(result1, result2)
+    assert list(result1.nodes()) == list(result2.nodes())
+    assert list(result1.edges()) == list(result2.edges())
+
+
+@pytest.mark.asyncio
+async def test_stable_largest_connected_component_directed_graph():
+    G = nx.DiGraph()
+    G.add_edges_from([("A", "B"), ("B", "C"), ("C", "D"), ("E", "F")])
+    result = NetworkXStorage.stable_largest_connected_component(G)
+    assert sorted(result.nodes()) == ["A", "B", "C", "D"]
+    assert sorted(result.edges()) == [("A", "B"), ("B", "C"), ("C", "D")]
+
+
+@pytest.mark.asyncio
+async def test_stable_largest_connected_component_self_loops_and_parallel_edges():
+    G = nx.Graph()
+    G.add_edges_from([("A", "B"), ("B", "C"), ("C", "A"), ("A", "A"), ("B", "B"), ("A", "B")])
+    result = NetworkXStorage.stable_largest_connected_component(G)
+    assert sorted(result.nodes()) == ["A", "B", "C"]
+    assert sorted(result.edges()) == [('A', 'A'), ('A', 'B'), ('A', 'C'), ('B', 'B'), ('B', 'C')]
+
+
+@pytest.mark.asyncio
+async def test_community_schema_with_no_clusters(networkx_storage):
+    await networkx_storage.upsert_node("node1", {"source_id": "chunk1"})
+    await networkx_storage.upsert_node("node2", {"source_id": "chunk2"})
+    await networkx_storage.upsert_edge("node1", "node2", {})
+    
+    community_schema = await networkx_storage.community_schema()
+    assert len(community_schema) == 0
+
+
+@pytest.mark.asyncio
+async def test_community_schema_multiple_levels(networkx_storage):
+    await networkx_storage.upsert_node("node1", {"source_id": "chunk1", "clusters": json.dumps([{"level": 0, "cluster": "0"}, {"level": 1, "cluster": "1"}])})
+    await networkx_storage.upsert_node("node2", {"source_id": "chunk2", "clusters": json.dumps([{"level": 0, "cluster": "0"}, {"level": 1, "cluster": "2"}])})
+    await networkx_storage.upsert_edge("node1", "node2", {})
+    
+    community_schema = await networkx_storage.community_schema()
+    assert len(community_schema) == 3
+    assert set(community_schema.keys()) == {"0", "1", "2"}
+    assert community_schema["0"]["level"] == 0
+    assert community_schema["1"]["level"] == 1
+    assert community_schema["2"]["level"] == 1
+    assert set(community_schema["0"]["sub_communities"]) == {"1", "2"}
+
+
+@pytest.mark.asyncio
+async def test_community_schema_occurrence(networkx_storage):
+    await networkx_storage.upsert_node("node1", {"source_id": "chunk1,chunk2", "clusters": json.dumps([{"level": 0, "cluster": "0"}])})
+    await networkx_storage.upsert_node("node2", {"source_id": "chunk3", "clusters": json.dumps([{"level": 0, "cluster": "0"}])})
+    await networkx_storage.upsert_node("node3", {"source_id": "chunk4", "clusters": json.dumps([{"level": 0, "cluster": "1"}])})
+    
+    community_schema = await networkx_storage.community_schema()
+    assert len(community_schema) == 2
+    assert community_schema["0"]["occurrence"] == 1
+    assert community_schema["1"]["occurrence"] == 0.5
+
+
+@pytest.mark.asyncio
+async def test_community_schema_sub_communities(networkx_storage):
+    await networkx_storage.upsert_node("node1", {"source_id": "chunk1", "clusters": json.dumps([{"level": 0, "cluster": "0"}, {"level": 1, "cluster": "1"}])})
+    await networkx_storage.upsert_node("node2", {"source_id": "chunk2", "clusters": json.dumps([{"level": 0, "cluster": "0"}, {"level": 1, "cluster": "2"}])})
+    await networkx_storage.upsert_node("node3", {"source_id": "chunk3", "clusters": json.dumps([{"level": 0, "cluster": "3"}, {"level": 1, "cluster": "4"}])})
+    
+    community_schema = await networkx_storage.community_schema()
+    assert len(community_schema) == 5
+    assert set(community_schema["0"]["sub_communities"]) == {"1", "2"}
+    assert community_schema["3"]["sub_communities"] == ["4"]
+    assert community_schema["1"]["sub_communities"] == []
+    assert community_schema["2"]["sub_communities"] == []
+    assert community_schema["4"]["sub_communities"] == []
+
+
+@pytest.mark.asyncio
+async def test_concurrent_operations(networkx_storage):
+    async def add_nodes(start, end):
+        for i in range(start, end):
+            await networkx_storage.upsert_node(f"node{i}", {"value": i})
+
+    await asyncio.gather(
+        add_nodes(0, 500),
+        add_nodes(500, 1000)
+    )
+
+    assert await networkx_storage.node_degree("node0") == 0
+    assert len(networkx_storage._graph.nodes) == 1000
+
+
+@pytest.mark.asyncio
+async def test_nonexistent_node_and_edge(networkx_storage):
+    assert await networkx_storage.has_node("nonexistent") is False
+    assert await networkx_storage.has_edge("node1", "node2") is False
+    assert await networkx_storage.get_node("nonexistent") is None
+    assert await networkx_storage.get_edge("node1", "node2") is None
+    assert await networkx_storage.get_node_edges("nonexistent") is None
+    assert await networkx_storage.node_degree("nonexistent") == 0
+    assert await networkx_storage.edge_degree("node1", "node2") == 0
+
+
+@pytest.mark.asyncio
+async def test_error_handling(networkx_storage):
+    with pytest.raises(ValueError, match="Clustering algorithm invalid_algo not supported"):
+        await networkx_storage.clustering("invalid_algo")
+
+    with pytest.raises(ValueError, match="Node embedding algorithm invalid_algo not supported"):
+        await networkx_storage.embed_nodes("invalid_algo")