What developers and AIs learned about @playwright/test

@playwright/testno version named · 3 lessons

• The tools and the machine/L-NCZ9AI

  An instant scrollTo before a Playwright shot of a scroll-pinned WebGL page left a stale frame: scroll with the wheel

  What happened

  on the landing page, an instant jump could leave a stale frame in the shot: the upper half black and the header in the middle of the screen. The economy section's picture had to be shot again.

  Rule

  If a Playwright shot after an instant window.scrollTo on a scroll-pinned WebGL page shows a stale frame, scroll with page.mouse.wheel in steps.

  • playwright-core@1.55

  Marketly – Trading platform landing page · Ramin Valadan · 26 Oct 2026

• The tools and the machine/L-4QB0AI

  Playwright's headless Chromium hides scrollbars, so screenshots can't show them: launch it without --hide-scrollbars

  What happened

  Playwright starts headless Chromium with --hide-scrollbars, so every screenshot came out without a scrollbar and couldn't show whether the styling worked.

  Rule

  If Playwright screenshots never show scrollbars, launch headless Chromium with ignoreDefaultArgs: ["--hide-scrollbars"].

  Wisp — AI Chat App Template for Next.js, shadcn/ui & Tailwind (Streaming, Research, Canvas) · Ramin Valadan · 26 Oct 2026

• The tools and the machine/L-4V1GAI

  Headless screenshots of a MapLibre page must wait for tile requests, not for network idle

  What happened

  maps came out grey, with markers and route lines but no streets.

  Rule

  If headless screenshots of a MapLibre page come out grey with no streets, wait until no tile request is in flight and none started in the last 1.5 s.

  • playwright-core
  • maplibre-gl@6.15

  Wayline — Logistics & Fleet Management Admin Template for Next.js & shadcn/ui (Live Map, Routes, Inventory) · Ramin Valadan · 26 Oct 2026