6 files changed, 28 insertions, 26 deletions
diff --git a/src/modules/optional/arrange.js b/src/modules/optional/arrange.js
index 30151c1..9aaeef1 100644
--- a/src/modules/optional/arrange.js
+++ b/src/modules/optional/arrange.js
@@ -23,8 +23,8 @@ export function prev () {
 
 // Send given element one step forward
 export function forward () {
-  var i = this.position()
-  var p = this.parent()
+  const i = this.position()
+  const p = this.parent()
 
   // move node one step forward
   p.add(this.remove(), i + 1)
@@ -34,8 +34,8 @@ export function forward () {
 
 // Send given element one step backward
 export function backward () {
-  var i = this.position()
-  var p = this.parent()
+  const i = this.position()
+  const p = this.parent()
 
   p.add(this.remove(), i ? i - 1 : 0)
 
@@ -44,7 +44,7 @@ export function backward () {
 
 // Send given element all the way to the front
 export function front () {
-  var p = this.parent()
+  const p = this.parent()
 
   // Move node forward
   p.add(this.remove())
@@ -54,7 +54,7 @@ export function front () {
 
 // Send given element all the way to the back
 export function back () {
-  var p = this.parent()
+  const p = this.parent()
 
   // Move node back
   p.add(this.remove(), 0)
@@ -67,7 +67,7 @@ export function before (element) {
   element = makeInstance(element)
   element.remove()
 
-  var i = this.position()
+  const i = this.position()
 
   this.parent().add(element, i)
 
@@ -79,7 +79,7 @@ export function after (element) {
   element = makeInstance(element)
   element.remove()
 
-  var i = this.position()
+  const i = this.position()
 
   this.parent().add(element, i + 1)
 
diff --git a/src/modules/optional/class.js b/src/modules/optional/class.js
index b08c82b..4e544be 100644
--- a/src/modules/optional/class.js
+++ b/src/modules/optional/class.js
@@ -3,7 +3,7 @@ import { registerMethods } from '../../utils/methods.js'
 
 // Return array of classes on the node
 export function classes () {
-  var attr = this.attr('class')
+  const attr = this.attr('class')
   return attr == null ? [] : attr.trim().split(delimiter)
 }
 
@@ -15,7 +15,7 @@ export function hasClass (name) {
 // Add class to the node
 export function addClass (name) {
   if (!this.hasClass(name)) {
-    var array = this.classes()
+    const array = this.classes()
     array.push(name)
     this.attr('class', array.join(' '))
   }
diff --git a/src/modules/optional/data.js b/src/modules/optional/data.js
index 9986c3d..00bb8ea 100644
--- a/src/modules/optional/data.js
+++ b/src/modules/optional/data.js
@@ -24,9 +24,11 @@ export function data (a, v, r) {
     }
   } else {
     this.attr('data-' + a,
-      v === null ? null
-      : r === true || typeof v === 'string' || typeof v === 'number' ? v
-      : JSON.stringify(v)
+      v === null
+        ? null
+        : r === true || typeof v === 'string' || typeof v === 'number'
+          ? v
+          : JSON.stringify(v)
     )
   }
 
diff --git a/src/modules/optional/memory.js b/src/modules/optional/memory.js
index 6478367..459dcf1 100644
--- a/src/modules/optional/memory.js
+++ b/src/modules/optional/memory.js
@@ -4,7 +4,7 @@ import { registerMethods } from '../../utils/methods.js'
 export function remember (k, v) {
   // remember every item in an object individually
   if (typeof arguments[0] === 'object') {
-    for (var key in k) {
+    for (const key in k) {
       this.remember(key, k[key])
     }
   } else if (arguments.length === 1) {
@@ -23,7 +23,7 @@ export function forget () {
   if (arguments.length === 0) {
     this._memory = {}
   } else {
-    for (var i = arguments.length - 1; i >= 0; i--) {
+    for (let i = arguments.length - 1; i >= 0; i--) {
       delete this.memory()[arguments[i]]
     }
   }
diff --git a/src/modules/optional/sugar.js b/src/modules/optional/sugar.js
index 13806f1..d4c3da5 100644
--- a/src/modules/optional/sugar.js
+++ b/src/modules/optional/sugar.js
@@ -6,7 +6,7 @@ import Point from '../../types/Point.js'
 import SVGNumber from '../../types/SVGNumber.js'
 
 // Define list of available attributes for stroke and fill
-var sugar = {
+const sugar = {
   stroke: [ 'color', 'width', 'opacity', 'linecap', 'linejoin', 'miterlimit', 'dasharray', 'dashoffset' ],
   fill: [ 'color', 'opacity', 'rule' ],
   prefix: function (t, a) {
@@ -16,8 +16,8 @@ var sugar = {
 
 // Add sugar for fill and stroke
 ;[ 'fill', 'stroke' ].forEach(function (m) {
-  var extension = {}
-  var i
+  const extension = {}
+  let i
 
   extension[m] = function (o) {
     if (typeof o === 'undefined') {
@@ -104,7 +104,7 @@ registerMethods([ 'Element', 'Runner' ], {
 registerMethods('radius', {
   // Add x and y radius
   radius: function (x, y = x) {
-    var type = (this._element || this).type
+    const type = (this._element || this).type
     return type === 'radialGradient'
       ? this.attr('r', new SVGNumber(x))
       : this.rx(x).ry(y)
diff --git a/src/modules/optional/transform.js b/src/modules/optional/transform.js
index 68455ed..d8e7381 100644
--- a/src/modules/optional/transform.js
+++ b/src/modules/optional/transform.js
@@ -10,11 +10,11 @@ export function untransform () {
 
 // merge the whole transformation chain into one matrix and returns it
 export function matrixify () {
-  var matrix = (this.attr('transform') || '')
+  const matrix = (this.attr('transform') || '')
     // split transformations
     .split(transforms).slice(0, -1).map(function (str) {
       // generate key => value pairs
-      var kv = str.trim().split('(')
+      const kv = str.trim().split('(')
       return [ kv[0],
         kv[1].split(delimiter)
           .map(function (str) {
@@ -37,8 +37,8 @@ export function matrixify () {
 // add an element to another parent without changing the visual representation on the screen
 export function toParent (parent, i) {
   if (this === parent) return this
-  var ctm = this.screenCTM()
-  var pCtm = parent.screenCTM().inverse()
+  const ctm = this.screenCTM()
+  const pCtm = parent.screenCTM().inverse()
 
   this.addTo(parent, i).untransform().transform(pCtm.multiply(ctm))
 
@@ -54,7 +54,7 @@ export function toRoot (i) {
 export function transform (o, relative) {
   // Act as a getter if no object was passed
   if (o == null || typeof o === 'string') {
-    var decomposed = new Matrix(this).decompose()
+    const decomposed = new Matrix(this).decompose()
     return o == null ? decomposed : decomposed[o]
   }
 
@@ -64,8 +64,8 @@ export function transform (o, relative) {
   }
 
   // The user can pass a boolean, an Element or an Matrix or nothing
-  var cleanRelative = relative === true ? this : (relative || false)
-  var result = new Matrix(cleanRelative).transform(o)
+  const cleanRelative = relative === true ? this : (relative || false)
+  const result = new Matrix(cleanRelative).transform(o)
   return this.attr('transform', result)
 }