refactoring to es6

Author: stipsan

src/legacy.ts

@@ -7,17 +7,17 @@
  */
 
 // These values are established by empiricism with tests (tradeoff: performance VS precision)
-var NEWTON_ITERATIONS = 4
-var NEWTON_MIN_SLOPE = 0.001
-var SUBDIVISION_PRECISION = 0.0000001
-var SUBDIVISION_MAX_ITERATIONS = 10
+const NEWTON_ITERATIONS = 4
+const NEWTON_MIN_SLOPE = 0.001
+const SUBDIVISION_PRECISION = 0.0000001
+const SUBDIVISION_MAX_ITERATIONS = 10
 
-var kSplineTableSize = 11
-var kSampleStepSize = 1.0 / (kSplineTableSize - 1.0)
+const kSplineTableSize = 11
+const kSampleStepSize = 1.0 / (kSplineTableSize - 1.0)
 
-var float32ArraySupported = typeof Float32Array === 'function'
+const float32ArraySupported = typeof Float32Array === 'function'
 
-function A(aA1, aA2) {
+const A = (aA1, aA2) => {
   return 1.0 - 3.0 * aA2 + 3.0 * aA1
 }
 function B(aA1, aA2) {
@@ -28,16 +28,16 @@ function C(aA1) {
 }
 
 // Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
-function calcBezier(aT, aA1, aA2) {
+const calcBezier = (aT, aA1, aA2) => {
   return ((A(aA1, aA2) * aT + B(aA1, aA2)) * aT + C(aA1)) * aT
 }
 
 // Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
-function getSlope(aT, aA1, aA2) {
+const getSlope = (aT, aA1, aA2) => {
   return 3.0 * A(aA1, aA2) * aT * aT + 2.0 * B(aA1, aA2) * aT + C(aA1)
 }
 
-function binarySubdivide(aX, aA, aB, mX1, mX2) {
+const binarySubdivide = (aX, aA, aB, mX1, mX2) => {
   var currentX,
     currentT,
     i = 0
@@ -56,7 +56,7 @@ function binarySubdivide(aX, aA, aB, mX1, mX2) {
   return currentT
 }
 
-function newtonRaphsonIterate(aX, aGuessT, mX1, mX2) {
+const newtonRaphsonIterate = (aX, aGuessT, mX1, mX2) => {
   for (var i = 0; i < NEWTON_ITERATIONS; ++i) {
     var currentSlope = getSlope(aGuessT, mX1, mX2)
     if (currentSlope === 0.0) {
@@ -68,7 +68,7 @@ function newtonRaphsonIterate(aX, aGuessT, mX1, mX2) {
   return aGuessT
 }
 
-function bezier(mX1, mY1, mX2, mY2) {
+const bezier = (mX1, mY1, mX2, mY2) => {
   if (!(0 <= mX1 && mX1 <= 1 && 0 <= mX2 && mX2 <= 1)) {
     throw new Error('bezier x values must be in [0, 1] range')
   }
@@ -83,7 +83,7 @@ function bezier(mX1, mY1, mX2, mY2) {
     }
   }
 
-  function getTForX(aX) {
+  const getTForX = aX => {
     var intervalStart = 0.0
     var currentSample = 1
     var lastSample = kSplineTableSize - 1
@@ -119,7 +119,7 @@ function bezier(mX1, mY1, mX2, mY2) {
     }
   }
 
-  return function BezierEasing(x) {
+  return x => {
     if (mX1 === mY1 && mX2 === mY2) {
       return x // linear
     }
@@ -135,15 +135,15 @@ function bezier(mX1, mY1, mX2, mY2) {
 }
 
 // Predefined set of animations. Similar to CSS easing functions
-var animations = {
+const animations = {
   ease: bezier(0.25, 0.1, 0.25, 1),
   easeIn: bezier(0.42, 0, 1, 1),
   easeOut: bezier(0, 0, 0.58, 1),
   easeInOut: bezier(0.42, 0, 0.58, 1),
   linear: bezier(0, 0, 1, 1),
 }
 
-export function animate(source, target, options) {
+export const animate = (source, target, options) => {
   var start = Object.create(null)
   var diff = Object.create(null)
   options = options || {}
@@ -167,7 +167,7 @@ export function animate(source, target, options) {
   var scheduler = getScheduler(options.scheduler)
 
   var keys = Object.keys(target)
-  keys.forEach(function(key) {
+  keys.forEach(key => {
     start[key] = source[key]
     diff[key] = target[key] - source[key]
   })

src/transition.ts

@@ -38,17 +38,17 @@ export interface Options extends CalculateOptions {
   easing?: 'ease' | 'easeIn' | 'easeOut' | 'easeInOut' | 'linear'
 }
 
-function isBoolean(options: boolean | Options): options is boolean {
+const isBoolean = (options: boolean | Options): options is boolean => {
   return typeof options === 'boolean'
 }
 
-export default function scrollIntoViewIfNeeded(
+const scrollIntoViewIfNeeded = (
   target: Element,
   options: boolean | Options,
   animateOptions?: AnimateOptions,
   finalElement?: Element,
   offsetOptions: OffsetConfig = {}
-) {
+) => {
   if (!target || !(target instanceof HTMLElement))
     throw new Error('Element is required in scrollIntoViewIfNeeded')
 
@@ -89,3 +89,5 @@ export default function scrollIntoViewIfNeeded(
 
   return calculate(target, config)
 }
+
+export default scrollIntoViewIfNeeded