Cucumber.js

Cucumber.js turns Gherkin scenarios into executable checks for Node.js projects. It is best suited to JavaScript teams using Behaviour-Driven Development to make examples part of collaboration and testing. Its open-source model is a clear advantage, but teams must connect scenarios to code themselves and install the package locally.

Overview

Cucumber evaluates plain-text specifications and reports success or failure for each scenario. The scenarios use Gherkin and are typically kept in .feature files alongside the software in source control, giving teams a shared format for examples of expected behavior. They become useful checks only when step definitions connect each step to code that performs the described actions, so teams should be ready to maintain both the scenarios and their implementation.

Cucumber.js is the stable, canonical JavaScript implementation, distributed as the @cucumber/cucumber npm module for Node.js. The project describes @cucumber/node as pre-1.0.0 and subject to change; teams choosing Cucumber for JavaScript should use the canonical package. The project says thousands of companies rely on Cucumber tests to validate software, though that does not remove the effort of fitting scenarios to an application.

Key features

Scenarios and step definitions

Step definitions can use Cucumber Expressions or regular expressions, but the syntaxes cannot be mixed within one expression. This offers a choice in how teams match scenario steps to code, while requiring consistency within each expression. Cucumber.js includes a command-line executable for running feature files and supports parallel execution.

Reports and CI

Reporter plugins can produce results showing which scenarios passed or failed. Options include built-in, separately installed and custom plugins, allowing teams to select or build a reporting approach suited to their workflow. Cucumber can run in continuous integration, and Cucumber Reports can include links to detected Git commits and CI runs.

Report publishing is supported by Cucumber-JS version 7.0.0 and above; the --publish option is supported from version 7.3.0. Published reports are publicly accessible and deleted after 24 hours, so this option is unsuitable for results that must remain private. Cucumber Reports says report data is stored in US data centers and encrypted at rest.

Browser automation and security

Cucumber is not a browser automation tool, but it can work with tools such as Selenium WebDriver. Teams seeking browser checks need to pair it with an automation tool rather than expect Cucumber.js to drive a browser by itself.

The project has a security policy for contacting maintainers about security issues and advises against defining environment variables containing secrets globally. Users can take questions to Discord, GitHub Discussions or Stack Overflow. Cucumber says its intellectual property assets transitioned from SmartBear Software to the Open Source Collective in December 2024.

Pricing

Cucumber.js is free and open source, with two free plan entries priced at $0. Both describe availability as an npm module installed as a development dependency. There is no free trial to distinguish from the free offering, and no paid tier is described; the cost advantage comes with the setup and maintenance work of writing step definitions and project-level installation.

Platforms

Cucumber.js supports Node.js and is available for Linux, macOS, Windows and self-hosted environments. The JavaScript setup requires Node.js and either npm or Yarn. Install @cucumber/cucumber as a development dependency; a global install will not work because globally installed modules cannot be imported or required in support files.

Who it's for

Cucumber.js is a strong fit for Node.js teams that want executable Gherkin examples to support a Behaviour-Driven Development process built around discovery, collaboration and examples. It is less suitable for teams looking for a ready-made browser automation tool or unwilling to implement and maintain step definitions. Teams should also avoid global installation and treat published reports as public.

Pros and cons

• Pros: Free, open-source tooling turns Gherkin scenarios into per-scenario pass-or-fail checks, with source-controlled feature files that can sit beside the software.
• Pros: Command-line execution, parallel runs, reporter plugins and CI support give teams several ways to fit checks into development workflows.
• Cons: Step definitions must connect each scenario to working code, creating ongoing implementation and maintenance work.
• Cons: Global installation is unsupported, and browser automation requires a separate tool such as Selenium WebDriver.
• Cons: Published reports are public, even though they are deleted after 24 hours; sensitive results should not be published this way.

Alternatives

For a broader comparison, see JavaScript Testing Frameworks and Test Automation Software. Consider these alternatives when their stated scope or platform coverage better matches your project:

• Karma is free and covers more platforms, but its software is deprecated, with no new features or general bug fixes.
• QUnit is a free, open-source JavaScript testing framework distributed through CDN, npm and Yarn.
• Web Test Runner is an alternative for teams focused on modern web development and browser work.
• Pure Test is a free, Apache-2.0 open-source option for supported web and self-hosted platforms.
• Vitest is a free, open-source option for its listed Linux, macOS, web and Windows platforms.
• Testem is a free, MIT-licensed JavaScript test runner for Linux, macOS and Windows.
• Mocha is a free, open-source JavaScript test framework installed as a development dependency.
• Rstest is a free, MIT-licensed JavaScript and TypeScript testing framework for its listed extension and web platforms.

Verdict

Choose Cucumber.js if your Node.js team wants Gherkin examples to serve as executable, collaborative checks and is prepared to maintain the step definitions behind them. Its main draw is a free, established approach to scenario-based testing with CI and reporting support. Look elsewhere if you need browser automation built in, or if your workflow depends on globally installed packages or private published reports.