Cucumber.js vs Japa

Cucumber.js checks software against executable specifications written as plain-text scenarios, reporting whether each scenario passes or fails. It is the JavaScript implementation of Cucumber and runs on Node.js. Scenarios use Gherkin syntax and are usually kept in `.feature` files alongside the software in source control. Step definitions connect each Gherkin step to code that carries out its described action; expressions can use Cucumber Expressions or regular expressions, but not both syntaxes in a single expression.

The tool runs feature files from the command line and can run in continuous integration, including parallel execution. Reporter plugins can produce results, and reports can be published to Cucumber Reports with `--publish`. Published reports are public and deleted after 24 hours. Cucumber.js is available as the `@cucumber/cucumber` npm module, installed as a development dependency with npm or Yarn. The setup requires Node.js and one of those package managers. It is free and open source, with Linux, macOS, Windows, and self-hosted platforms listed. It works with browser automation tools, but is not itself one.

Japa is a free testing framework for Node.js backend applications and libraries, including JSON API and browser testing. Tests can be arranged into suites and groups with lifecycle hooks, filtering, asynchronous execution, datasets, snapshots, pinned tests, and bail mode. Assertion choices include Chai-based assert, Jest-style expect, and TypeScript type assertions. Its API client tests endpoints returning JSON, XML, HTML, or plain text, while an OpenAPI plugin checks responses against a schema. Browser testing uses a Playwright-based client with browser and context management, built-in assertions, and tracing options. Coverage reporting is documented with c8 or nyc. Japa has an official VS Code extension and an AdonisJS preset. It has no separate CLI; tests run from a configured entry point with Node.js or Bun. Setup occurs inside an existing Node.js project, where users select assertion libraries and optional plugins. Japa requires Node.js 18 or later, runs without transpilers, and works only with the ES module system.