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World Congress 2025 • Aug 20, 2025 • Session details

The 2025 State of JavaScript Testing

Daniel Afonso

Is Jest officially dead? Discover why Vitest and Playwright dominate the 2025 testing landscape, and how AI-powered, self-healing tests are finally eliminating flaky CI pipelines.

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#1 about 2 min

Reflecting on the core motivations for writing tests

Identifying the personal and organizational reasons for testing frames the discussion around modern developer workflows.

#2 about 3 min

Analyzing developer pain points from the State of JS

Survey data reveals that network mocking, configuration complexity, and flakiness remain top challenges driving low satisfaction scores.

#3 about 5 min

Comparing JavaScript testing stacks across eight different companies

Interviews with real-world developers highlight how test categories and tooling selections diverge depending on organizational maturity.

#4 about 2 min

Reviewing static analysis within the modern testing trophy

TypeScript and ESLint remain foundational for stability, while emerging tools like Biome and OXC merit close observation.

#5 about 4 min

Tracing the evolution of unit and integration testing

The shift from browser-based runners to JSDOM and Testing Library altered how teams categorize and write component assertions.

#6 about 6 min

Transitioning to browser mode using Vitest and Vite

Emulating browsers in Node creates discrepancies, pushing the ecosystem to rely on Vitest browser mode for authentic component testing.

#7 about 4 min

Exploring the expansion of end-to-end testing utility suites

Playwright leads the market while end-to-end runners increasingly incorporate visual, API, and accessibility testing into unified platforms.

#8 about 2 min

Implementing network mocking with Mock Service Worker APIs

Cross-process interception capabilities in Mock Service Worker enable seamless API simulation across both client and server environments.

#9 about 4 min

Applying visual language models for automated self-healing tests

Advanced AI tools and language models like UI TARS reduce brittle test assertions by interpreting user interfaces visually.

#10 about 1 min

Generating test suites rapidly with Model Context Protocol

Providing AI agents direct integration with testing tools via Model Context Protocol auto-generates comprehensive end-to-end test files.

#11 about 2 min

Treating testing infrastructure as a first-class priority

Embracing emerging tools and component testing ensures software resilience and prevents critical production regressions during on-call periods.

Matching moments

3:32 min

Implementing automated UI tests with Jest and Puppeteer

Miki Lombardi · JS Congress

2:32 min

Comparing Puppeteer with Playwright and Selenium frameworks

Miki Lombardi · JS Congress

2:40 min

Transitioning toward modern end-to-end testing tools

Jessica Janiuk · JS Congress

2:23 min

Keeping up with Web3 testing tools

Soumaya Erradi · LIVE

4:20 min

JavaScript runtime competition and built-in features

1:47 min

Core architectural assumptions for expressive and scalable testing

Leszek Włodarski Leszek Włodarski · WWC Europe 2026

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