`react-doctor/rn-prefer-reanimated`

Consider Reanimated for a measured RN Animated or LayoutAnimation limitation after version and architecture checks

Status: Active
Category: React Native
Assessment: Evidence-required risk
Required evidence: source code
Default configuration: Enabled
Default severity: warn

Show technical metadata

Scope: React Native
Active when: framework=react-native and capabilities=react-native
Requirements: react-native
Tags: react-native, test-noise
Priority: 38 (P3)
Source: oxlint-plugin-react-doctor
Rule set: oxlint-plugin-react-doctor 0.9.3 (prompt schema 2)

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Validation prompt
Evidence boundary
Fix prompt
Repository-wide copy prompt

Validation prompt

Confirm the detector match and collect the required evidence before deciding whether an edit is warranted.

Determine whether the finding is a React Native Animated import or LayoutAnimation usage; they require different migrations. Confirm release-build evidence of a limitation that justifies the dependency, then inspect whether Reanimated is installed, its major version, the React Native version and architecture, and reduced-motion requirements. Reanimated v4 requires the New Architecture, react-native-worklets, and its worklets plugin; v3 setup differs. LayoutAnimation cannot be fixed by swapping an import.

Evidence boundary

The diagnostic proves only that the detector’s modeled source pattern matched. It does not prove runtime impact, product intent, rendered failure, or that one remediation is correct.

Establish the environment, repository policy, exceptions, and required rendered or runtime evidence before deciding the occurrence.

Record one outcome:

Confirmed failure: The required evidence establishes the violation.
Rejected: A documented exception or false-positive predicate applies.
Needs evidence: Named evidence can still be collected.
Unavailable: Required evidence cannot be collected in this run.
Waived with evidence: An authorized, scoped exception applies to an established failure.
Observation: The review records an optional tradeoff without claiming a defect.

A waiver records its scope, authority, evidence, and review condition. It is not a pass or false positive.

Default severity is registry metadata. Use the occurrence’s JSON severity after repository configuration when ordering real findings.

Fix prompt

Apply this candidate correction only after the required evidence confirms the risk.

When migration is measured and authorized, follow the installed Reanimated major's setup. Translate RN Animated graphs into equivalent shared values, animated styles, cancellation, completion, and reduced-motion behavior. Treat LayoutAnimation separately: use version-supported Reanimated layout transitions only when their mount/update/unmount and interruption semantics match. Do not add the dependency, enable the New Architecture, or apply a v3/v4 plugin recipe implicitly. Verify release builds on affected devices. See https://docs.swmansion.com/react-native-reanimated/docs/fundamentals/getting-started/

Repository-wide copy prompt

Use this repository-wide prompt only after validating each occurrence. For one occurrence, use the guidance above.

Show repository-wide prompt

Fix every confirmed react-doctor/rn-prefer-reanimated diagnostic in the current repository.

Required change:

When migration is measured and authorized, follow the installed Reanimated major's setup. Translate RN Animated graphs into equivalent shared values, animated styles, cancellation, completion, and reduced-motion behavior. Treat LayoutAnimation separately: use version-supported Reanimated layout transitions only when their mount/update/unmount and interruption semantics match. Do not add the dependency, enable the New Architecture, or apply a v3/v4 plugin recipe implicitly. Verify release builds on affected devices. See https://docs.swmansion.com/react-native-reanimated/docs/fundamentals/getting-started/.

Validation before editing:

Constraints:

Make the smallest change that fixes the root cause.
Preserve behavior and interfaces unrelated to this diagnostic.
Reuse existing project components, utilities, and conventions.
Do not introduce render-phase side effects, render-phase state updates, or Hooks rule violations.
Before editing, inspect the manifest, lockfile, native app configuration, React Native and Expo versions, and New Architecture status.
Also inspect the Reanimated major, installed list-library majors, and every affected platform-specific file.
Do not add or upgrade a native dependency, change linking, or alter Pods/Gradle setup unless explicitly authorized.
Do not enable the New Architecture or change Expo/native configuration unless explicitly authorized.
Preserve navigation, gesture, keyboard, safe-area, accessibility, lifecycle, and platform semantics; do not treat them as file-local import substitutions.
Verify behavior in a release build on each affected device platform in scope. Name any unavailable platform instead of claiming it passed.
Adapt identifiers and framework details instead of copying blindly.
Do not disable the rule or suppress matching code.
Confirm this rule is enabled for the project: framework=react-native and capabilities=react-native.

Assessment:

Record detector evidence, applicability facts, assumptions, missing evidence, and the rule class for this occurrence.
Return one outcome: Confirmed failure, Rejected, Needs evidence, Unavailable, Waived with evidence, or Observation.
A waiver records the established failure, scope, authority, evidence, and review or expiry condition. It is not a pass or false positive.

Verification:

Run focused tests for the changed behavior.
Run React Doctor and confirm this diagnostic no longer appears from changed code.
Run an unfiltered scan of the affected scope before claiming no cross-category regression.
Report the files changed and any checks you could not run.