How do you test GraphQL APIs differently from REST APIs?
- graphql
- query testing
- API differences
Answer it first, then compare. Nothing here is saved or scored.
Model answer
Key differences: (1) Single endpoint, so test different query shapes, not different URLs. (2) Test query depth limits and complexity to prevent abuse. (3) Test fragments, nested queries, and pagination (cursor-based). (4) Verify type system compliance, fields return correct types. (5) Test error handling, partial failures (some fields resolve, some error). (6) Subscription testing for real-time features. (7) Test query variables and input validation. (8) Performance: N+1 query detection, dataloader effectiveness. Use tools like graphql-request or Apollo testing utilities.
What interviewers listen for
- Schema-first thinkingYou validate response shape before you assert on values, every time.
- Status-code literacyYou can defend why 401 vs 403 vs 422 matters for the consumer.
- Contract awarenessYou know when consumer-driven contract tests beat end-to-end checks.
- Auth fluencyYou can describe rotating tokens across parallel workers without secrets in logs.