fix stagger speed

demo/src/StaggeredList/index.js

@@ -126,7 +126,7 @@ export default class AnimatedList extends Component {
         staggerConfig={{
           card: {
             reverse: this.state.focused !== null ? true : false,
-            speed: 0.5
+            speed: 0
           }
         }}
         decisionData={this.state.focused}

src/flip/animateFlippedElements/spring/__tests__/spring.test.js

@@ -0,0 +1,24 @@
+import { normalizeSpeed } from '../index'
+
+describe('normalizeSpeed', () => {
+  it('if not provided a number, it returns 1.1', () => {
+    expect(normalizeSpeed(null)).toBe(1.1)
+    expect(normalizeSpeed(undefined)).toBe(1.1)
+    expect(normalizeSpeed('string')).toBe(1.1)
+  })
+  it('if provided 1, returns 6', () => {
+    expect(normalizeSpeed(1)).toBe(6)
+  })
+
+  it('if provided 10, returns 6', () => {
+    expect(normalizeSpeed(10)).toBe(6)
+  })
+
+  it('if provided 0, returns 1', () => {
+    expect(normalizeSpeed(0)).toBe(1)
+  })
+
+  it('if provided -1, returns 1', () => {
+    expect(normalizeSpeed(-1)).toBe(1)
+  })
+})

src/flip/animateFlippedElements/spring/index.ts

@@ -42,6 +42,11 @@ export const createSpring = (flipped: FlipData) => {
   }
 }
 
+export const normalizeSpeed = (speedConfig: number | undefined) => {
+  if (typeof speedConfig !== 'number') return 1.1
+  return 1 + Math.min(Math.max(speedConfig * 5, 0), 5)
+}
+
 export const staggeredSprings = (
   flippedArray: FlipDataArray,
   staggerConfig: StaggerConfigValue = {}
@@ -54,9 +59,7 @@ export const staggeredSprings = (
     flippedArray.reverse()
   }
 
-  const normalizedSpeed = staggerConfig.speed
-    ? 1 + Math.max(Math.min(staggerConfig.speed, 0), 1)
-    : 1.1
+  const normalizedSpeed = normalizeSpeed(staggerConfig.speed)
 
   const nextThreshold = 1 / Math.max(Math.min(flippedArray.length, 100), 10)
 

types/index.d.ts

@@ -61,6 +61,7 @@ export const Flipped: React.SFC<FlippedProps>
 
 export interface StaggerConfigValue {
   reverse?: boolean
+  /** A number between 0 (for a slower stagger) and 1 (for a faster stagger) */
   speed: number
 }