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Upgrading react 16 to 17

Breaking16.14.0 → 17.0.2Breaking11Deprecated1New8Changed23Fixed25Other2

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BreakingUpgrade verdict

11 breaking changes.

In plain terms
  • Synthetic event objects are no longer reused, so they stay valid after the handler returns.
  • Removes unstable_discreteUpdates and unstable_flushDiscreteUpdates.
  • Removes the timeoutMs argument.
  • React now listens for events on each app root rather than on the whole page document.
Must act Top 4 of 12 that need code or config changes

Drops prop-types.

Installs 3 packages in all (was 5).

What you must change

Breaking11
Removes event pooling.
17.0.0GitHub ReleaseSummarizedView source
Removes unstable_discreteUpdates and unstable_flushDiscreteUpdates.
unstable_discreteUpdatesunstable_flushDiscreteUpdates
17.0.0GitHub ReleaseSummarizedView source
Removes the timeoutMs argument.
timeoutMs
17.0.0GitHub ReleaseSummarizedView source
Delegates events to roots instead of document.
17.0.0GitHub ReleaseSummarizedView source
Cleans up all effects before running any next effects.
17.0.0GitHub ReleaseSummarizedView source
Runs useEffect cleanup functions asynchronously.
useEffect
17.0.0GitHub ReleaseSummarizedView source
Stops emulating bubbling of the onScroll event.
onScroll
17.0.0GitHub ReleaseSummarizedView source
Throws if a forwardRef or memo component returns undefined.
forwardRefmemo
17.0.0GitHub ReleaseSummarizedView source
Stops exposing internals that won't be needed by React Native Web.
17.0.0GitHub ReleaseSummarizedView source
Disables <div hidden /> prerendering in favor of a different future API.
17.0.0GitHub ReleaseSummarizedView source
Adds the unstable_ prefix before the experimental APIs.
17.0.0GitHub ReleaseSummarizedView source

Deprecations to plan for

Deprecated1
Deprecates the undocumented and misleading ReactTestUtils.SimulateNative API.
ReactTestUtils.SimulateNative
17.0.0GitHub ReleaseSummarizedView source