Should.js

Should.js
Name	Should.js
Author	Rick Waldron
Initial release	2010
Latest release	4.x
Repository	GitHub
License	MIT

Should.js Should.js is a JavaScript assertion library designed for behavior-driven development and expressive testing. It provides fluent, chainable assertions intended to pair with test runners and frameworks used across server-side and client-side JavaScript ecosystems. The library is used in conjunction with popular tools to assert program behavior during unit, integration, and end-to-end testing.

Introduction

Should.js targets developers who write tests with frameworks and runners such as Mocha (JavaScript test framework), Jasmine (software), AVA (test runner), Karma (test runner), Jest, Tape (test harness), QUnit, Sinon (library), Chai (assertion library), Protractor, Nightwatch.js, Puppeteer, Cypress (software), WebdriverIO, TestCafe, Grunt (software), Gulp (software), Webpack, Rollup (software), Parcel (software), Browserify, Babel (software), TypeScript, Node.js, Deno (runtime), Electron (software framework), NW.js.

The library is commonly integrated into continuous integration and delivery systems such as Jenkins, Travis CI, CircleCI, GitLab CI/CD, GitHub Actions, Azure DevOps, Bamboo (software), TeamCity, Bitbucket Pipelines, and is distributed via package managers like npm (software), Yarn (package manager), pnpm.

History and Development

Should.js originated in the early 2010s amid a surge of JavaScript testing tooling driven by projects and organizations including YUI (library), jQuery, Dojo Toolkit, Node.js Foundation, Internet Explorer, Google, Mozilla Foundation, Microsoft, Facebook, Inc., Twitter, Inc., LinkedIn, GitHub, npm, Inc..

Development has been coordinated on platforms and services such as GitHub, with contributions from individual developers and teams at companies like WalmartLabs, IBM, Red Hat, PayPal, Uber Technologies, Airbnb, Microsoft Research, Google Chrome, Opera Software. Releases have been managed following semantic versioning practices popularized by projects like RubyGems and Semantic Versioning.

The project has been discussed at conferences and meetups such as NodeConf, JSConf, JSConf EU, React Conf, Chrome Dev Summit, ng-conf, jamstack_conf, EmberConf, Full Stack Fest, Open Source Summit, Google I/O, and has been included in publications and tutorials from outlets such as InfoQ, Smashing Magazine, SitePoint, O’Reilly Media, ACM, IEEE.

Features and API

Should.js offers an expressive, chainable API influenced by ideas in frameworks and libraries like RSpec, Jest, Chai (assertion library), Hamcrest, Sinon (library), Mocha (JavaScript test framework), Jasmine (software), Tape (test harness). It supports deep equality, type assertions, property assertions, and function behavior assertions commonly required in projects developed with React (JavaScript library), AngularJS, Vue.js, Svelte, Backbone.js, Ember.js.

Typical features mirror patterns found in established ecosystems such as Express (web framework), Koa (web framework), Hapi (software), Fastify, Meteor (software), Next.js, Nuxt.js, Gatsby (software), emphasizing compatibility with middleware patterns and asynchronous code used by Promise (computing), async/await, RxJS, GraphQL, Apollo (software), REST (Representational State Transfer) APIs.

API constructs often reference semantics recognizable from language-level constructs in ECMAScript 6, ECMAScript 2015, CommonJS, AMD (programming), UMD (pattern), and interoperate with tools like Babel (software), TypeScript type definitions, and linters such as ESLint and Prettier.

Usage and Examples

Common usage patterns appear in test codebases alongside technologies like Mocha (JavaScript test framework), Jest, Karma (test runner), Webpack, Babel (software), TypeScript, Node.js, Express (web framework), React (JavaScript library), Angular (web framework), Vue.js.

Examples are often demonstrated in blogs or books from publishers such as O’Reilly Media, Packt Publishing, Manning Publications, and in tutorials associated with courses on platforms like Coursera, Udemy, Pluralsight, edX, freeCodeCamp.

Integration and Tooling

Should.js integrates with build and automation ecosystems including Grunt (software), Gulp (software), Webpack, Rollup (software), Parcel (software), Babel (software), TypeScript, ESLint, Prettier, and CI/CD services like Jenkins, Travis CI, GitLab CI/CD, GitHub Actions.

It is commonly paired with browser automation and end-to-end frameworks such as Selenium (software), WebdriverIO, Puppeteer, Playwright, Cypress (software), Protractor, enabling assertion of UI state in projects developed by teams at organizations like Google, Microsoft, Amazon (company), Facebook, Inc..

Package distribution and dependency management occur through npm (software), Yarn (package manager), and repository hosting on GitHub, with issue tracking via GitHub Issues or GitLab.

Performance and Limitations

Performance characteristics are influenced by underlying JavaScript engines such as V8, SpiderMonkey, JavaScriptCore, and environments like Node.js, Deno (runtime), Electron (software framework). Deep equality checks and extensive introspection can be slower compared to minimalistic assertion libraries used in micro-benchmarks created with Benchmark.js.

Limitations reflect trade-offs similar to those observed in comparisons between Chai (assertion library), Expect.js, Should (programming language), and custom assertion strategies documented by engineering teams at Google, Facebook, Inc., Netflix, Inc..

Adoption and Community

Adoption spans open source projects and enterprises; contributors and users include developers from organizations such as GitHub, npm, Inc., Google, Microsoft, Facebook, Inc., IBM, PayPal, WalmartLabs, Uber Technologies, Airbnb, Netflix, Inc., LinkedIn, Mozilla Foundation, Red Hat, Canonical (company), SAP SE, Oracle Corporation, Salesforce.

Community activity is coordinated via channels including GitHub, Stack Overflow, Twitter, Reddit, Gitter, Slack (software), Discord (software), and event talks at JSConf, NodeConf, Open Source Summit.

Category:JavaScript libraries