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[internals] Harden useDisposable React internals read with safeReact - #22986
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rita-codes merged 5 commits intoJun 29, 2026
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`useDisposable` reads `__CLIENT_INTERNALS_…` / `__SECRET_INTERNALS_…` off the React namespace to detect StrictMode. The original direct read (`React.__SECRET_INTERNALS_…`) is rewritten by bundlers into a named import of `react` that React 19 doesn't export, which is the build break shipped in 9.6.0. mui#22882 mitigated it by reading through a local alias (`const X = React`). The alias works in webpack today but is the fragile form Base UI moved away from in material-ui#41190. Use the `safeReact` pattern instead: clone the namespace into a plain object (`{ ...React }`, compiled to `_extends({}, React)`). The read goes through a function-call result the bundler can't trace back to the `react` import, so it can't be rewritten into a named import on any bundler. No behavior change: missing keys are still `undefined` and fall through to a single dispose. Verified the built `.mjs` bundles clean in a webpack build against React 19, where the direct-access form errors with "`__SECRET_INTERNALS_…` is not exported from 'react'". Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Janpot
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Small optimization could be to reuse the safeReact object @base-ui/utils is already creating.
Per review: `@base-ui/utils` already exports a `SafeReact` clone of the React
namespace, and `useDisposable` already imports from `@base-ui/utils`. Read the
internals off that shared clone instead of building a second `{ ...React }`
locally. Same bundler-safety (a property read off a named import is never
rewritten into a `react` named import); one less clone.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Good call, fixed! ✅ |
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Context
useDisposablereads__CLIENT_INTERNALS_…/__SECRET_INTERNALS_…off the React namespace to detect StrictMode (so the store survives StrictMode'smount → unmount → mountcycle with synchronous dispose).The original read was direct —
React.__SECRET_INTERNALS_…. Bundlers rewrite that into a named import ofreact, and React 19 doesn't export__SECRET_INTERNALS_…, so the build fails with:This is the error shipped in
@mui/x-internals@9.6.0. #22882 already mitigated it by reading through a local alias (const X = React). The alias works in webpack today, but it's the fragile form Base UI deliberately moved away from in material-ui#41190.Change
Read the internals off Base UI's
SafeReact— a plain clone of the React namespace that@base-ui/utilsalready exports, and whichuseDisposablealready imports from — instead of offReactdirectly. A property read on a regular named import is never rewritten into areactnamed import, so the build error can't happen on any bundler.No behavior change: missing keys are still
undefinedand fall through to a single, normal dispose.Verification
@mui/x-internals).pnpm test:unit --project x-internals), including the StrictMode double-mount and<Activity>cases..mjsin a webpack build against React 19.2.6: the original direct-access form errors with'__SECRET_INTERNALS_…' was not found in 'react', and reading the internals offSafeReactbundles clean (0 errors).