fix: Cypher query extraction for node names with spaces

- Updated `extract_cypher` to wrap node label with spaces in quotes.
- Added tests for node names with one and multiple spaces.
- Renamed test cases to improve clarity.
- Checked lint and format.

libs/neo4j/langchain_neo4j/chains/graph_qa/cypher.py

@@ -57,8 +57,20 @@ def extract_cypher(text: str) -> str:
 
     # Find all matches in the input text
     matches = re.findall(pattern, text, re.DOTALL)
+    if matches:
+        cypher_query = matches[0]
+    else:
+        return text
 
-    return matches[0] if matches else text
+    # Remove backticks
+    cypher_query = cypher_query.replace("`", "")
+
+    # Quote node labels if they contain spaces
+    cypher_query = re.sub(
+        r":\s*(\s*)([a-zA-Z0-9_]+(?:\s+[a-zA-Z0-9_]+)+)(\s*)", r":'\2'", cypher_query
+    )
+
+    return cypher_query
 
 
 def construct_schema(

libs/neo4j/tests/unit_tests/chains/test_graph_qa.py

@@ -236,18 +236,43 @@ def test_graph_cypher_qa_chain() -> None:
     assert True
 
 
-def test_no_backticks() -> None:
+def test_extract_cypher_on_no_backticks() -> None:
     """Test if there are no backticks, so the original text should be returned."""
     query = "MATCH (n) RETURN n"
     output = extract_cypher(query)
     assert output == query
 
 
-def test_backticks() -> None:
+def test_extract_cypher_on_backticks() -> None:
     """Test if there are backticks. Query from within backticks should be returned."""
     query = "You can use the following query: ```MATCH (n) RETURN n```"
+    expected_output = "MATCH (n) RETURN n"
     output = extract_cypher(query)
-    assert output == "MATCH (n) RETURN n"
+    assert output == expected_output
+
+
+def test_extract_cypher_on_label_with_spaces() -> None:
+    """Test if node labels with spaces are quoted."""
+    query = "```MATCH (n:Label With Space) RETURN n```"
+    expected_output = "MATCH (n:'Label With Space') RETURN n"
+    output = extract_cypher(query)
+    assert output == expected_output
+
+
+def test_extract_cypher_on_label_with_multi_spaces() -> None:
+    """Test if node labels with multiple spaces are quoted."""
+    query = "```MATCH (n:Label With    Space) RETURN n```"
+    expected_output = "MATCH (n:'Label With    Space') RETURN n"
+    output = extract_cypher(query)
+    assert output == expected_output
+
+
+def test_extract_cypher_on_label_without_spaces() -> None:
+    """Test if node labels without spaces are not quoted."""
+    query = "```MATCH (n:LabelWithoutSpace) RETURN n```"
+    expected_output = "MATCH (n:LabelWithoutSpace) RETURN n"
+    output = extract_cypher(query)
+    assert output == expected_output
 
 
 def test_exclude_types() -> None: