Vitest vs WSO2 Contract Test Runner

Vitest is a free and open-source testing framework powered by Vite, though it can also run without Vite. It can reuse Vite configuration, plugins, resolvers, and transform pipelines. Jest-compatible APIs cover assertions, snapshots, and mocking, which can support migration from Jest. Watch mode reruns tests related to changed source or test files, and TypeScript, JSX, and ES modules work out of the box. Browser Mode runs tests in a browser and supports Playwright and WebdriverIO providers. Component testing covers Vue, React, Svelte, Lit, Marko, and other frameworks. Vitest supports coverage through V8 or Istanbul, benchmarking powered by Tinybench, parallel execution, parameterized cases, and property-based checks. An official Visual Studio Code extension is available, and the framework can be tried in StackBlitz without local installation. The listed requirements are Vite 6.4.0 or later and Node 22.12.0 or later. Help is available through the Vitest Discord community and GitHub Discussions.

WSO2 Contract Test Runner is a free, Apache-2.0-licensed library for consumer-based testing of live REST API endpoints. It sends requests and compares returned data with expected responses defined in JSON contracts. A contract can include a request, expected response, assertions, and optional post-conditions. Assertions cover status codes, JSON body and header paths, exact values, regular expressions, emptiness, structures, arrays, and objects. Tests run through Docker by mounting contract and configuration files into the documented image workflow. Suites can run contracts before or after tests, with before-suite contracts running synchronously. Post-conditions can place extracted values into suite-scoped or global environment variables, and contracts can pause for a specified number of seconds. The sample setup uses bearer authorization, cookies, a certificate keystore, and a client truststore. XML path support is listed as a todo. Deployment is Linux and self-hosted.