Mockers - Overcoming Testing Challenges at Grab

This post introduces Mockers, a Go SDK and CLI tool for managing a central monorepo of mock servers at Grab. Mockers simulates a staging environment on developer local boxes, expanding the scope of local box testing to include functional, resiliency, and contract tests. It generates mock servers for HTTP and gRPC microservices based on API specifications (Swagger for HTTP, protobuf for gRPC). Key features include automatic contract verification, out-of-the-box resiliency testing with repeatable tests (integrating with a chaos SDK), and simplified management of mock servers via CLI commands. The post also discusses the limitations of conventional staging environments and differentiates Mockers from unit tests with code mocks.