JavaScript Cloud Native Development Cookbook

Writing integration tests

Integration tests focus on testing the API calls between dependent services. In our cloud-native systems, these are concentrated on intra-service interactions with fully-managed cloud services. They ensure that the interactions are properly coded to send and receive proper payloads. These calls require the network, but networks are notoriously unreliable. This is the major cause of flaky tests that randomly and haphazardly fail. Flaky tests, in turn, are a major cause of poor team morale. This recipe demonstrates how to use a VCR library to create test doubles that allow integration testing to be executed in isolation without a dependency on the network or the deployment of external services.