SKILL.md
react-native-ease refactor
You are a migration assistant that converts react-native-reanimated and React Native's built-in Animated API code to react-native-ease EaseView components.
Follow these 6 phases exactly. Do not skip phases or reorder them.
Phase 1: Discovery
Scan the user's project for animation code:
-
Use Grep to detect if the project uses NativeWind:
- Pattern:
from ['"]nativewind['"]in**/*.{ts,tsx,js,jsx}
- Also check
package.jsonfor"nativewind"in dependencies
- If NativeWind is detected, set a flag
usesNativeWind = truefor use in Phase 5
-
Detect the Reanimated version (needed for default value mapping in Phase 2):
- Read
package.jsonand check thereact-native-reanimatedversion independenciesordevDependencies
- If the version is
^4or>=4.0.0, setreanimatedVersion = 4
- Otherwise set
reanimatedVersion = 3(covers v2/v3 which share the same defaults)
-
Use Grep to find all files importing from react-native-reanimated:
- Pattern:
from ['"]react-native-reanimated['"]
- Search in
**/*.{ts,tsx,js,jsx}
-
Use Grep to find all files using React Native's built-in Animated API:
- Pattern:
from ['"]react-native['"]that also useAnimated
- Pattern:
Animated\.View|Animated\.Text|Animated\.Image|Animated\.Value|Animated\.timing|Animated\.spring
-
Use Grep to find files already using react-native-ease (to avoid re-migrating):
- Pattern:
from ['"]react-native-ease['"]
-
Read each file that contains animation code. Build a list of components with their animation patterns.
Exclude from scanning:
node_modules/
*.test.*and*.spec.*files
- Build output directories (
lib/,build/,dist/)
Phase 2: Classification
For each component found, classify as migratable or not migratable.
Decision Tree
Apply these checks in order. The first match determines the result:
- Uses gesture APIs? (
Gesture.Pan,Gesture.Pinch,Gesture.Rotation,useAnimatedGestureHandler) → NOT migratable — "Gesture-driven animation"
- Uses scroll handler? (
useAnimatedScrollHandler,onScrollwithAnimated.event) → NOT migratable — "Scroll-driven animation"
- Uses shared element transitions? (
sharedTransitionTag) → NOT migratable — "Shared element transition"
- **Uses
runOnUIor worklet directives?** → NOT migratable — "Requires worklet runtime"
- **Uses
withSequence?** → NOT migratable — "Animation sequencing not supported"
5b. **Uses withDelay wrapping a single animation (withTiming/withSpring)?** → MIGRATABLE — map to delay on the transition
5c. **Uses withDelay wrapping withSequence or nested withDelay?** → NOT migratable — "Complex delay/sequencing not supported"
- **Uses complex
interpolate()?** (more than 2 input/output values) → NOT migratable — "Complex interpolation"
- **Uses
layout={...}prop?** → NOT migratable — "Layout animation"
- Animates unsupported properties? (anything besides: opacity, translateX, translateY, scale, scaleX, scaleY, rotate, rotateX, rotateY, borderRadius, backgroundColor, borderWidth, borderColor, shadowOpacity, shadowRadius, shadowColor, shadowOffset, elevation) → NOT migratable — "Animates unsupported property:
<prop>"
- Uses different transition configs per property? (e.g., opacity uses 200ms timing, scale uses spring) → MIGRATABLE — map to
TransitionMapwith category keys (transform,opacity,borderRadius,backgroundColor,border,shadow,default)
- Not driven by state? (animation triggered by gesture/scroll value, not React state) → NOT migratable — "Not state-driven"
- Otherwise → MIGRATABLE
Migratable Pattern Mapping
Use this table to convert Reanimated/Animated patterns to EaseView:
Reanimated / Animated Pattern
EaseView Equivalent
useSharedValue + useAnimatedStyle + withTiming for opacity, translate, scale, rotate, borderRadius, backgroundColor
animate={{ prop: value }} + transition={{ type: 'timing', duration, easing }}
withSpring
transition={{ type: 'spring', damping, stiffness, mass }}
entering={FadeIn} / FadeIn.duration(N)
initialAnimate={{ opacity: 0 }} + animate={{ opacity: 1 }} + timing transition
entering={FadeInDown} / FadeInUp
initialAnimate={{ opacity: 0, translateY: ±value }} + animate={{ opacity: 1, translateY: 0 }}
entering={SlideInLeft} / SlideInRight
initialAnimate={{ translateX: ±value }} + animate={{ translateX: 0 }}
entering={SlideInUp} / SlideInDown
initialAnimate={{ translateY: ±value }} + animate={{ translateY: 0 }}
entering={ZoomIn}
initialAnimate={{ scale: 0 }} + animate={{ scale: 1 }}
exiting={FadeOut} / other exit animations
State-driven exit: boolean state + onTransitionEnd to unmount (flag as "requires state changes" in report)
withRepeat(withTiming(...), -1, false)
transition={{ type: 'timing', ..., loop: 'repeat' }} + initialAnimate for start value
withRepeat(withTiming(...), -1, true)
transition={{ type: 'timing', ..., loop: 'reverse' }} + initialAnimate for start value
Easing.linear
easing: 'linear'
Easing.ease / Easing.inOut(Easing.ease)
easing: 'easeInOut'
Easing.in(Easing.ease)
easing: 'easeIn'
Easing.out(Easing.ease)
easing: 'easeOut'
Easing.bezier(x1, y1, x2, y2)
easing: [x1, y1, x2, y2]
Animated.Value + Animated.timing
Same animate + transition pattern — convert to state-driven
Animated.Value + Animated.spring
animate + transition={{ type: 'spring' }} — convert to state-driven
withDelay(ms, withTiming(...)) or withDelay(ms, withSpring(...))
transition={{ ..., delay: ms }} — add delay to the transition config
entering={FadeIn.delay(ms)} / any entering preset with .delay()
initialAnimate + animate + transition={{ ..., delay: ms }}
Different withTiming/withSpring per property in useAnimatedStyle
transition={{ opacity: { type: 'timing', ... }, transform: { type: 'spring', ... } }} (per-property map)
Default Value Mapping
CRITICAL: Reanimated and EaseView have different defaults. You MUST explicitly set values to preserve the original animation behavior. Do not rely on EaseView defaults matching Reanimated defaults.
**Use reanimatedVersion from Phase 1 to select the correct defaults.**
#### withSpring → EaseView spring
Reanimated v2/v3 defaults:
Parameter
Reanimated v2/v3
EaseView default
Action
damping
10
15
**Must set damping: 10**
stiffness
100
120
**Must set stiffness: 100**
mass
1
1
Same — omit
Reanimated v4 defaults:
Parameter
Reanimated v4
EaseView default
Action
damping
120
15
**Must set damping: 120**
stiffness
900
120
**Must set stiffness: 900**
mass
4
1
**Must set mass: 4**
Reanimated v4 changed to a critically damped, snappy spring (no bounce) as the default. The rationale was that the old physics-based defaults were too sensitive to start/end conditions. v4 recommends using duration + dampingRatio instead of raw physics params.
If the source code explicitly sets any of these values, carry them over as-is. If the source relies on Reanimated defaults (no explicit value), set the Reanimated default explicitly on the EaseView transition.
Example — bare withSpring(1) with no config:
// Before (Reanimated)
scale.value = withSpring(1);
// After (EaseView) — v2/v3: set damping: 10, stiffness: 100
transition={{ type: 'spring', damping: 10, stiffness: 100 }}
// After (EaseView) — v4: set damping: 120, stiffness: 900, mass: 4
transition={{ type: 'spring', damping: 120, stiffness: 900, mass: 4 }}
Duration-based spring: Reanimated v3+ also supports withSpring(target, { duration, dampingRatio }). If the code explicitly sets dampingRatio/duration, convert using: damping = dampingRatio * 2 * sqrt(stiffness * mass).
#### withTiming → EaseView timing
Parameter
Reanimated default
EaseView default
Action
duration
300
300
Same — omit
easing
Easing.inOut(Easing.quad)
'easeInOut' (cubic)
**Must set easing: [0.455, 0.03, 0.515, 0.955]**
The easing curves are different! Reanimated's default is quadratic ease-in-out, EaseView's is cubic. Always set the easing explicitly when the source doesn't specify one.
Example — bare withTiming(1) with no config:
// Before (Reanimated)
opacity.value = withTiming(1);
// After (EaseView) — must set quad easing to match
transition={{ type: 'timing', duration: 300, easing: [0.455, 0.03, 0.515, 0.955] }}
If the source explicitly sets an easing, map it using the easing table above.
#### Animated.timing (old RN API) → EaseView timing
Parameter
RN Animated default
EaseView default
Action
duration
500
300
**Must set duration: 500**
easing
Easing.inOut(Easing.ease)
'easeInOut'
Same curve — omit
#### Animated.spring (old RN API) → EaseView spring
RN Animated uses friction/tension by default: friction: 7, tension: 40. These map to: stiffness = tension, damping = friction.
Parameter
RN Animated default
EaseView default
Action
stiffness (tension)
40
120
**Must set stiffness: 40**
damping (friction)
7
15
**Must set damping: 7**
mass
1
1
Same — omit
Unit Conversions
- Rotation: Reanimated uses
'45deg'strings in transforms → EaseView uses45(number, degrees). Strip the'deg'suffix and parse to number.
- Translation: Both use DIPs (density-independent pixels). No conversion needed.
- Scale: Both use unitless multipliers. No conversion needed.
Phase 3: Dry-Run Report
ALWAYS print this report before asking the user to select components. This report must be visible to the user before Phase 4.
Print a structured report. Do NOT apply any changes yet.
Format:
## Migration Report
### Summary
- Files scanned: X
- Components with animations: Y
- Migratable: Z | Not migratable: W
### Migratable Components
#### `path/to/file.tsx` — ComponentName
**Current:** Brief description of what the animation does and which API it uses
**Proposed:** What the EaseView equivalent looks like (include exact transition values with mapped defaults)
**Changes:** What will be added/removed/modified
**Note:** (only if applicable) "Requires state changes for exit animation" or other caveats
### Not Migratable (will be skipped)
#### `path/to/file.tsx` — ComponentName
**Reason:** Why it can't be migrated (from decision tree)
This report MUST be printed as text output in the conversation — not inside a plan, not collapsed. The user needs to read it before selecting components in Phase 4.
Phase 4: User Confirmation
**CRITICAL: You MUST use the AskUserQuestion tool here. Do NOT use plan mode, do NOT use text prompts, do NOT ask inline. Call the AskUserQuestion tool directly.**
Call AskUserQuestion with these exact parameters:
multiSelect:true
questions: a single question object with:
header:"Migrate"
question:"Which components should be migrated to EaseView? All are selected — deselect any to skip."
multiSelect:true
options: one entry per migratable component, each with:
label: the component name (e.g.,"AnimatedButton")
description: file path and brief animation description (e.g.,"src/components/animated-button.tsx — spring scale on press")
Example tool call for 2 migratable components:
{
"questions": [
{
"header": "Migrate",
"question": "Which components should be migrated to EaseView? All are selected — deselect any to skip.",
"multiSelect": true,
"options": [
{
"label": "AnimatedButton",
"description": "src/components/simple/animated-button.tsx — spring scale on press"
},
{
"label": "Collapsible",
"description": "src/components/ui/collapsible.tsx — fade-in entering animation"
}
]
}
]
}
Wait for the user's response before proceeding. Do not enter plan mode. Do not apply any changes without the user selecting components.
If the user selects nothing or chooses "Other" to cancel, abort with: "Migration aborted. No changes were made."
Only proceed to Phase 5 with the components the user confirmed.
Phase 5: Apply Migrations
For each confirmed component, apply the migration:
Migration Steps (per component)
-
Add EaseView import if not already present:
import { EaseView } from 'react-native-ease';
1b. **If usesNativeWind is true**, check if import 'react-native-ease/nativewind' already exists in the project (search all files). If not, add it to the app's root entry point (e.g., _layout.tsx, App.tsx, or index.tsx — whichever is the earliest entry). This only needs to be done once across all migrations, not per component.
-
Replace the animated view:
Animated.View→EaseView
<Animated.View style={[styles.box, animatedStyle]}>→<EaseView style={styles.box} animate={{ ... }} transition={{ ... }}>
-
Convert animation hooks to props:
- Remove
useSharedValue,useAnimatedStyle,withTiming,withSpring,withRepeatcalls
- Convert their values into
animate,initialAnimate, andtransitionprops
-
Convert entering/exiting animations:
-
entering={FadeIn} → initialAnimate={{ opacity: 0 }} on the EaseView + animate={{ opacity: 1 }}
-
For exiting: introduce a state variable and onTransitionEnd callback:
const [visible, setVisible] = useState(true);
const [mounted, setMounted] = useState(true);
// When triggering exit:
setVisible(false);
// On the EaseView:
{
mounted && (
<EaseView
animate={{ opacity: visible ? 1 : 0 }}
transition={{ type: 'timing', duration: 300 }}
onTransitionEnd={({ finished }) => {
if (finished && !visible) setMounted(false);
}}
>
...
</EaseView>
);
}
-
Clean up imports:
- Remove Reanimated imports that are no longer used in the file
- Keep any Reanimated imports still referenced by non-migrated code in the same file
- Never remove imports that are still used
-
Print progress:
[1/N] Migrated ComponentName in path/to/file.tsx
Safety Rules
These rules are non-negotiable. Violating them corrupts user code.
- When in doubt, skip. If a pattern is ambiguous or you're not confident in the migration, add it to "Not Migratable" with reason: "Complex pattern — manual review recommended"
- Never remove imports still used elsewhere in the file. After removing animation code, check every remaining line for references to each import before removing it.
- Preserve all non-animation logic. Event handlers, state management, effects, callbacks — touch none of it unless directly related to the animation being migrated.
- Preserve component structure and public API. Props, ref forwarding, exported types — keep them identical.
- Handle mixed files correctly. If a file has both migratable and non-migratable animations, only migrate the safe ones. Keep Reanimated imports if any Reanimated code remains.
- Map rotation units correctly. Reanimated
'45deg'string → EaseView45number. If the source uses radians, convert:radians * (180 / Math.PI).
- Map easing presets correctly. See the mapping table in Phase 2.
- Do not introduce TypeScript errors. Ensure all types are correct after migration. If the original code uses typed shared values, ensure the EaseView props match.
Phase 6: Final Report
After all migrations are applied, print:
## Migration Complete
### Changed (X components)
- `path/to/file.tsx` — ComponentName: brief description of what was migrated
### Unchanged (Y components)
- `path/to/file.tsx` — ComponentName: reason skipped
### Next Steps
- Run your app and verify animations visually
- Run your test suite to check for regressions
- If no Reanimated code remains, consider removing `react-native-reanimated` from dependencies
EaseView API Reference (for migration accuracy)
Supported Animatable Properties
All properties in the animate prop:
Property
Type
Default
Notes
opacity
number
1
0–1 range
translateX
number
0
In DIPs (density-independent pixels)
translateY
number
0
In DIPs
scale
number
1
Shorthand for scaleX + scaleY
scaleX
number
1
Overrides scale for X axis
scaleY
number
1
Overrides scale for Y axis
rotate
number
0
Z-axis rotation in degrees
rotateX
number
0
X-axis rotation in degrees (3D)
rotateY
number
0
Y-axis rotation in degrees (3D)
borderRadius
number
0
In pixels
backgroundColor
ColorValue
'transparent'
Any RN color value
borderWidth
number
0
In pixels
borderColor
ColorValue
'black'
Any RN color value
shadowOpacity
number
0
0–1 (iOS only)
shadowRadius
number
0
In pixels (iOS only)
shadowColor
ColorValue
'black'
Any RN color value (iOS only)
shadowOffset
object
{width:0,height:0}
{ width, height } (iOS only)
elevation
number
0
Android material shadow
Transition Types
Timing:
transition={{
type: 'timing',
duration: 300, // ms, default 300
easing: 'easeInOut', // 'linear' | 'easeIn' | 'easeOut' | 'easeInOut' | [x1,y1,x2,y2]
delay: 0, // ms, default 0
loop: 'repeat', // 'repeat' | 'reverse' — requires initialAnimate
}}
Spring:
transition={{
type: 'spring',
damping: 15, // default 15
stiffness: 120, // default 120
mass: 1, // default 1
delay: 0, // ms, default 0
}}
None (instant):
transition={{ type: 'none' }}
Key Props
animate— target values for animated properties
initialAnimate— starting values (animates toanimateon mount)
transition— animation config: a singleSingleTransition(timing/spring/none) OR aTransitionMapwith category keys (default,transform,opacity,borderRadius,backgroundColor,border,shadow)
onTransitionEnd— callback with{ finished: boolean }
transformOrigin— pivot point as{ x: 0-1, y: 0-1 }, default center
useHardwareLayer— Android GPU optimization (boolean, default false)
className— NativeWind / Tailwind CSS class string (requires NativeWind in the project)
Important Constraints
- Loop requires timing (not spring) and
initialAnimatemust define the start value
- Per-property transitions supported — pass a
TransitionMapwith category keys (default,transform,opacity,borderRadius,backgroundColor,border,shadow) to use different configs per property group
- No animation sequencing — no equivalent to
withSequence. SimplewithDelayIS supported via thedelaytransition prop
- No gesture/scroll-driven animations — EaseView is state-driven only
- Style/animate conflict — if a property appears in both
styleandanimate, the animated value wins