7.4Query Complexity Analysis

Beyond depth, GraphQL servers should also limit query complexity:

class TestQueryComplexity:
    """Test query complexity limits."""

    def test_complexity_score_calculation(self, graphql_client):
        """Verify the server correctly calculates and limits complexity."""
        # A query that requests many items with nested relations
        # Each `first: N` multiplies the complexity
        query = """
        query {
          users(first: 100) {           # complexity: 100
            orders(first: 50) {          # complexity: 100 * 50 = 5000
              items(first: 20) {         # complexity: 5000 * 20 = 100000
                product {
                  reviews(first: 10) {   # complexity: 100000 * 10 = 1000000
                    author { name }
                  }
                }
              }
            }
          }
        }
        """
        response = graphql_client.execute(query)

        # This query should be blocked due to excessive complexity
        assert "errors" in response
        error_messages = [e["message"] for e in response["errors"]]
        assert any("complexity" in msg.lower() for msg in error_messages)