feat: add "isAnimated" helper

Author: aleclarson

src/animated/Animated.ts

@@ -1,3 +1,7 @@
+export function isAnimated(val: unknown): val is Animated {
+  return val instanceof Animated
+}
+
 export abstract class Animated<Payload = unknown> {
   public abstract getValue(): any
   public getAnimatedValue() {
@@ -37,11 +41,11 @@ export abstract class AnimatedArray<
   protected payload!: Payload
 
   public attach() {
-    this.payload.forEach(p => p instanceof Animated && p.addChild(this))
+    this.payload.forEach(p => isAnimated(p) && p.addChild(this))
   }
 
   public detach() {
-    this.payload.forEach(p => p instanceof Animated && p.removeChild(this))
+    this.payload.forEach(p => isAnimated(p) && p.removeChild(this))
   }
 }
 
@@ -56,11 +60,10 @@ export class AnimatedObject<
     const payload: { [key: string]: any } = {}
     for (const key in this.payload) {
       const value = this.payload[key]
-      if (animated && !(value instanceof Animated)) continue
-      payload[key] =
-        value instanceof Animated
-          ? value[animated ? 'getAnimatedValue' : 'getValue']()
-          : value
+      if (animated && !isAnimated(value)) continue
+      payload[key] = isAnimated(value)
+        ? value[animated ? 'getAnimatedValue' : 'getValue']()
+        : value
     }
     return payload
   }
@@ -70,14 +73,12 @@ export class AnimatedObject<
   }
 
   public attach() {
-    Object.values(this.payload).forEach(
-      s => s instanceof Animated && s.addChild(this)
-    )
+    Object.values(this.payload).forEach(s => isAnimated(s) && s.addChild(this))
   }
 
   public detach() {
     Object.values(this.payload).forEach(
-      s => s instanceof Animated && s.removeChild(this)
+      s => isAnimated(s) && s.removeChild(this)
     )
   }
 }

src/animated/AnimatedValue.ts

@@ -1,4 +1,4 @@
-import { Animated } from './Animated'
+import { Animated, isAnimated } from './Animated'
 import { AnimatedProps } from './AnimatedProps'
 import { Animatable, SpringValue } from '../types/animated'
 import { InterpolatorArgs } from '../types/interpolation'
@@ -53,7 +53,7 @@ export class AnimatedValue<T = number> extends Animated
   public done = false
 
   static from(value: any) {
-    return value instanceof AnimatedValue ? value : new AnimatedValue(value)
+    return isAnimated(value) ? value : new AnimatedValue(value)
   }
 
   constructor(value: T) {

src/index.ts

@@ -17,5 +17,6 @@ export { useTransition } from './useTransition'
 export { config } from './shared/constants'
 export { interpolate } from './interpolate'
 export { Controller } from './animated/Controller'
+export { isAnimated } from './animated/Animated'
 
 export * from './legacy'

src/targets/native/AnimatedTransform.ts

@@ -1,4 +1,4 @@
-import { Animated } from '../../animated/Animated'
+import { Animated, isAnimated } from '../../animated/Animated'
 
 type Transform = { [key: string]: string | number | Animated }
 
@@ -15,7 +15,7 @@ export class AnimatedTransform extends Animated {
       let result: { [key: string]: unknown } = {}
       for (var key in transform) {
         var value = transform[key]
-        result[key] = value instanceof Animated ? value.getValue() : value
+        result[key] = isAnimated(value) ? value.getValue() : value
       }
       return result
     })
@@ -26,8 +26,7 @@ export class AnimatedTransform extends Animated {
       let result: { [key: string]: unknown } = {}
       for (var key in transform) {
         var value = transform[key]
-        result[key] =
-          value instanceof Animated ? value.getAnimatedValue() : value
+        result[key] = isAnimated(value) ? value.getAnimatedValue() : value
       }
       return result
     })
@@ -37,7 +36,7 @@ export class AnimatedTransform extends Animated {
     this._transforms.forEach(transform => {
       for (var key in transform) {
         var value = transform[key]
-        if (value instanceof Animated) value.addChild(this)
+        if (isAnimated(value)) value.addChild(this)
       }
     })
   }
@@ -46,7 +45,7 @@ export class AnimatedTransform extends Animated {
     this._transforms.forEach(transform => {
       for (var key in transform) {
         var value = transform[key]
-        if (value instanceof Animated) value.removeChild(this)
+        if (isAnimated(value)) value.removeChild(this)
       }
     })
   }