What is the most effective approach to testing GraphQL APIs?

REST API testing feels natural with pytest + requests, but I'm not sure how to apply the same discipline to GraphQL. Specific questions: - Do you test individual resolvers or only full queries? - How do you handle deeply nested response validation? - Schema testing — do you snapshot the introspection output and fail on changes? - Any good Python libraries for GraphQL API testing beyond just POST-ing to `/graphql`? Our stack is Strawberry (Python) + a React frontend. Looking for both unit-level and integration-level strategies.