Cucumber.js vs uvu

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.

uvu is a free, lightweight test runner for Node.js and browser projects. It supports individually executable test files, asynchronous tests that may return Promises, native ES modules and a familiar API. Tests can be grouped into named suites or registered through a simpler test interface, and snapshot testing is supported. Each file is self-contained and can also be run directly with Node.js. The optional CLI collects and executes suites, with options to stop after the first failure, ignore patterns, preload modules, set a working directory and colorize output. When a directory is specified, file matching takes a regular-expression pattern rather than relying on glob patterns. The optional assertion module works in browsers and can be swapped for another library, including Node.js’s native assert. Installation uses `npm install --save-dev uvu`. Package metadata specifies Node.js version `>=8`; the repository identifies the project as MIT licensed and credits Luke Edwards.