https://www.youngju.dev/blog 천천히 올바르게. AI Researcher & DevOps Engineer Youngju's tech blog. GPU/CUDA, LLM, MLOps, Kubernetes AI workloads, distributed training, and data engineering. ko fjvbn2003@gmail.com (Youngju Kim) fjvbn2003@gmail.com (Youngju Kim) Sat, 16 May 2026 00:00:00 GMT https://www.youngju.dev/blog/culture/2026-05-16-frontend-testing-2026-playwright-cypress-vitest-storybook-9-chromatic-visual-regression-deep-dive.en https://www.youngju.dev/blog/culture/2026-05-16-frontend-testing-2026-playwright-cypress-vitest-storybook-9-chromatic-visual-regression-deep-dive.en May 2026, the landscape of frontend testing has shifted completely. Playwright is the de facto standard (VS Code integration, Trace Viewer, mature Component Testing); Cypress 14 is still strong but losing share. Vitest 3 is the fastest unit runner that ships with Vite; Jest 30 is the last bastion of legacy and Next compatibility. The Testing Library philosophy is no longer a recommendation but a duty. Storybook 9 (June 2025) got lighter and deeply integrated with Vitest. Visual regression breaks into two camps: Chromatic, Percy, Applitools (SaaS) vs. Loki, BackstopJS, Reg-Suit (OSS). Browser MCP / Playwright MCP has emerged, letting AI agents author and run tests. Mock with MSW, replace Page Object with Component Testing, and learn how Toss, Kakao, and Mercari actually use it. Sat, 16 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) testingfrontendplaywrightcypressvitestjesttesting-librarystorybookchromaticpercyapplitoolsmswvisual-regression2026deep-diveenglish https://www.youngju.dev/blog/culture/2026-05-16-frontend-testing-2026-playwright-cypress-vitest-storybook-9-chromatic-visual-regression-deep-dive.ja https://www.youngju.dev/blog/culture/2026-05-16-frontend-testing-2026-playwright-cypress-vitest-storybook-9-chromatic-visual-regression-deep-dive.ja 2026年5月、フロントエンドテストの地形は完全に変わった。Playwrightは事実上の標準(VS Code統合、Trace Viewer、Component Testingの成熟)、Cypress 14は依然強力だがシェアを落としつつある。Vitest 3はViteと共に来る最速ユニットランナー、Jest 30はレガシーとNext互換の最後の砦。Testing Libraryの哲学はもはや推奨ではなく義務。Storybook 9(2025年6月)は軽量化し、Vitestと深く統合した。ビジュアルリグレッションはChromatic・Percy・Applitools(SaaS)対Loki・BackstopJS・Reg-Suit(OSS)の二陣営。Browser MCP / Playwright MCPの登場で、AIエージェントが直接テストを書き実行する。MSWでネットワークをモックし、Page Objectの代わりにComponent Testingが標準となり、トス・カカオ・メルカリがどう使っているかまで。 Sat, 16 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) testingfrontendplaywrightcypressvitestjesttesting-librarystorybookchromaticpercyapplitoolsmswvisual-regression2026deep-dive日本語 https://www.youngju.dev/blog/culture/2026-05-16-frontend-testing-2026-playwright-cypress-vitest-storybook-9-chromatic-visual-regression-deep-dive https://www.youngju.dev/blog/culture/2026-05-16-frontend-testing-2026-playwright-cypress-vitest-storybook-9-chromatic-visual-regression-deep-dive 2026년 5월, 프론트엔드 테스팅의 지형이 완전히 바뀌었다. Playwright는 사실상 표준이 되었고(VSCode 통합, Trace Viewer, Component Testing 성숙), Cypress 14는 여전히 강하지만 점유율을 잃고 있다. Vitest 3는 Vite와 함께 오는 가장 빠른 유닛 테스트 러너, Jest 30은 레거시·Next 호환의 마지막 보루. Testing Library 철학은 이제 단순한 권장사항이 아니라 의무. Storybook 9(2025.6)는 가벼워지고 Vitest와 깊게 통합됐다. 시각적 회귀는 Chromatic, Percy, Applitools(SaaS) vs. Loki, BackstopJS, Reg-Suit(오픈소스)의 양강 구도. Browser MCP / Playwright MCP가 등장하면서 AI 에이전트가 직접 테스트를 짜고 실행한다. MSW로 네트워크를 모킹하고, Page Object 패턴 대신 Component Testing이 표준이 되고, 토스·카카오·Mercari가 어떻게 쓰는지까지. Sat, 16 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) testingfrontendplaywrightcypressvitestjesttesting-librarystorybookchromaticpercyapplitoolsmswvisual-regression2026deep-dive