v10.0.0

10.0.0 (2026-07-31)

• feat!: v10 — modernised toolchain, React 19 support, long-standing fixes (5647fab)

BREAKING CHANGES

• named export only (no default), /polyfilled entrypoint
  removed, zero runtime dependencies (@juggle/resize-observer dropped), react-dom
  no longer a peer, React >=18.2, ES2020 output (no IE11), and only the package
  root is importable. Full list with rationale in MIGRATION.md.

Toolchain (rebuilt end to end)

• Build: rollup + babel → tsdown (ESM + CJS + type declarations).
• Tests: jest + karma → Vitest in real browsers (Playwright), plus a
  WebdriverIO / BrowserStack suite on real desktop & mobile devices.
• Lint / format: eslint + prettier → oxlint + oxfmt.
• Package manager: yarn → pnpm; CI on Node 24 with OIDC trusted publishing.

Library

• React 19 support (18 kept); open-ended peer range so future majors work
  without a release here.
• onResize payload now carries the raw ResizeObserverEntry (every box size,
  entry.target), cross-window / iframe observation, and a measured 0 reports
  as 0 rather than undefined.