How do you implement Mocking in a GraphQL Server?

GraphQL's strong typing allows servers to automatically generate mock data for the entire schema without manual endpoint mocking.

Libraries like @graphql-tools/mock traverse the AST and schema types. If a query asks for a String, it generates "Hello World". If it asks for an Int, it returns a random number. You can provide custom mock functions to return realistic data (like Faker.js integration).