Fleet vs Jest: What are the differences?
Developers describe Fleet as "Container management and deployment for your cluster". Fleet is a low-level cluster engine that feels like a distributed init system. With fleet, you can treat your CoreOS cluster as if it shared a single init system. On the other hand, Jest is detailed as "Painless JavaScript Unit Testing". Jest provides you with multiple layers on top of Jasmine.
Fleet and Jest are primarily classified as "Container" and "Javascript Testing Framework" tools respectively.
Some of the features offered by Fleet are:
- Deploy docker containers on arbitrary hosts in a cluster
- Distribute services across a cluster using machine-level anti-affinity
- Maintain N instances of a service, re-scheduling on machine failure
On the other hand, Jest provides the following key features:
- Familiar Approach: Built on top of the Jasmine test framework, using familiar expect(value).toBe(other) assertions
- Mock by Default: Automatically mocks CommonJS modules returned by require(), making most existing code testable
- Short Feedback Loop: DOM APIs are mocked and tests run in parallel via a small node.js command line utility
Fleet and Jest are both open source tools. It seems that Jest with 26.4K GitHub stars and 3.57K forks on GitHub has more adoption than Fleet with 2.45K GitHub stars and 309 GitHub forks.