Test Automation
Stencil generates standard Web Components — Custom Elements with Shadow DOM — that run in any framework or vanilla HTML. That portability is the point, but it creates a testing challenge: your components need to work correctly both in isolation and when embedded in React, Angular, Vue, or plain HTML. Stencil comes
Test Automation
Lit builds on the Web Components standard — LitElement extends HTMLElement directly, uses the browser's native Custom Elements and Shadow DOM APIs, and adds a reactive property system and tagged template literal rendering. The result is small, fast web components that work anywhere. Testing Lit components requires real browser
JavaScript
Async JavaScript is everywhere — fetch calls, timers, event handlers, database queries. Testing async code correctly requires understanding how the JavaScript event loop works and how Jest and Vitest provide tools to control it. Async Test Functions Both Jest and Vitest support async/await in test functions natively: // Jest or Vitest
Testing
ESLint catches code style and quality issues; Jest enforces behavior through tests. Combined in GitHub Actions quality gates, they block merges when code doesn't meet your team's standards. This guide covers the complete setup — from configuration to PR annotations and coverage enforcement. Why Quality Gates, Not
Testing
WebdriverIO has first-class TypeScript support — types ship with the package, the setup wizard generates TypeScript configs, and the entire API surface is typed. Using TypeScript with WebdriverIO catches selector mistakes at compile time, gives you IDE autocomplete for browser APIs, and makes page objects more maintainable. This guide covers setting
Testing
Browser automation has never been more accessible to JavaScript developers. WebdriverIO brings the power of the WebDriver protocol to the Node.js ecosystem with a clean API, excellent TypeScript support, and a plugin ecosystem that covers almost every testing need. This tutorial walks you through everything you need to get
Testing
WebdriverIO ships with Mocha as its default test framework, and the combination is a natural fit. Mocha's describe/it structure keeps tests readable, its hooks give you fine-grained control over setup and teardown, and its async support pairs cleanly with WebdriverIO's promise-based API. This guide covers
Testing
As WebdriverIO test suites grow, tests that embed raw selectors and action logic directly become a maintenance burden. Change a CSS class, rename a button, or restructure a page — suddenly dozens of tests need updating. The Page Object Model (POM) solves this by creating a layer of abstraction between your
Testing Tools
Istanbul is the most widely used JavaScript code coverage tool. Its CLI wrapper nyc makes it trivial to add coverage instrumentation to any Node.js project. This guide covers setup, configuration, coverage thresholds, CI integration, and how to actually use coverage data to improve your tests. What Istanbul/nyc Measures
Testing
React Testing Library (RTL) has become the standard for testing React components. It replaced Enzyme as the go-to tool because it tests behavior, not implementation. If you're still testing internal state or calling component methods directly, you're doing it wrong — and RTL is here to fix
Testing
Storybook started as a UI development tool — a sandbox where you could render components in isolation and iterate on them without spinning up your whole application. That's still what most people use it for. But since Storybook 7, it has grown into a legitimate component testing platform. You
Testing
Jest is fast enough — until it isn't. Once your test suite crosses a few hundred tests, you start feeling it: the five-second startup, the transform overhead, the config file that has evolved into something no one fully understands. Bun's built-in test runner is a direct answer