diff --git a/src/demo/BasicDemo.js b/src/demo/BasicDemo.js
index 89bd5bc9..5acee933 100644
--- a/src/demo/BasicDemo.js
+++ b/src/demo/BasicDemo.js
@@ -43,8 +43,8 @@ class Demo {
   }
 
   handleShift() {
-    let currentLayout = this.keyboard.options.layoutName;
-    let shiftToggle = currentLayout === "default" ? "shift" : "default";
+    const currentLayout = this.keyboard.options.layoutName;
+    const shiftToggle = currentLayout === "default" ? "shift" : "default";
 
     this.keyboard.setOptions({
       layoutName: shiftToggle
diff --git a/src/demo/ButtonThemeDemo.js b/src/demo/ButtonThemeDemo.js
index 6fde284e..2ca3d738 100644
--- a/src/demo/ButtonThemeDemo.js
+++ b/src/demo/ButtonThemeDemo.js
@@ -61,8 +61,8 @@ class Demo {
   }
 
   handleShift() {
-    let currentLayout = this.keyboard.options.layoutName;
-    let shiftToggle = currentLayout === "default" ? "shift" : "default";
+    const currentLayout = this.keyboard.options.layoutName;
+    const shiftToggle = currentLayout === "default" ? "shift" : "default";
 
     this.keyboard.setOptions({
       layoutName: shiftToggle
diff --git a/src/demo/FullKeyboardDemo.js b/src/demo/FullKeyboardDemo.js
index e4ff3714..2fd05f3c 100644
--- a/src/demo/FullKeyboardDemo.js
+++ b/src/demo/FullKeyboardDemo.js
@@ -27,7 +27,7 @@ class Demo {
     /**
      * Demo Start
      */
-    let commonKeyboardOptions = {
+    const commonKeyboardOptions = {
       onChange: input => this.onChange(input),
       onKeyPress: button => this.onKeyPress(button),
       theme: "simple-keyboard hg-theme-default hg-layout-default",
@@ -116,8 +116,8 @@ class Demo {
       }
     });
 
-    document.querySelector(".input").addEventListener("input", event => {
-      let input = document.querySelector(".input").value;
+    document.querySelector(".input").addEventListener("input", () => {
+      const input = document.querySelector(".input").value;
       this.keyboard.setInput(input);
     });
   }
@@ -145,8 +145,8 @@ class Demo {
   }
 
   handleShift() {
-    let currentLayout = this.keyboard.options.layoutName;
-    let shiftToggle = currentLayout === "default" ? "shift" : "default";
+    const currentLayout = this.keyboard.options.layoutName;
+    const shiftToggle = currentLayout === "default" ? "shift" : "default";
 
     this.keyboard.setOptions({
       layoutName: shiftToggle
diff --git a/src/demo/MultipleKeyboardsDestroyDemo.js b/src/demo/MultipleKeyboardsDestroyDemo.js
index 36f028d9..2ac60340 100644
--- a/src/demo/MultipleKeyboardsDestroyDemo.js
+++ b/src/demo/MultipleKeyboardsDestroyDemo.js
@@ -76,9 +76,9 @@ class Demo {
   }
 
   handleShift(keyboardInstanceKey) {
-    let keyboard = this[keyboardInstanceKey || "keyboard"];
-    let currentLayout = keyboard.options.layoutName;
-    let shiftToggle = currentLayout === "default" ? "shift" : "default";
+    const keyboard = this[keyboardInstanceKey || "keyboard"];
+    const currentLayout = keyboard.options.layoutName;
+    const shiftToggle = currentLayout === "default" ? "shift" : "default";
 
     keyboard.setOptions({
       layoutName: shiftToggle
diff --git a/src/demo/tests/BasicDemo.test.js b/src/demo/tests/BasicDemo.test.js
index 61c76455..4ee67ab1 100644
--- a/src/demo/tests/BasicDemo.test.js
+++ b/src/demo/tests/BasicDemo.test.js
@@ -1,18 +1,18 @@
 import TestUtility from '../../utils/TestUtility';
 import BasicDemo from '../BasicDemo';
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('Demo will load', () => {
   testUtil.setDOM();
 
-  let demo = new BasicDemo();
+  new BasicDemo();
 });
 
 it('Demo onDOMLoaded will work', () => {
   testUtil.setDOM();
 
-  let demo = new BasicDemo();
+  const demo = new BasicDemo();
 
   expect(demo.keyboard).toBeTruthy();
 });
@@ -20,7 +20,7 @@ it('Demo onDOMLoaded will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new BasicDemo();
+  const demo = new BasicDemo();
 
   demo.onChange("test");
   
@@ -30,7 +30,7 @@ it('Demo onChange will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new BasicDemo();
+  const demo = new BasicDemo();
 
   demo.keyboard.getButtonElement("q").onclick();
   
@@ -40,7 +40,7 @@ it('Demo onChange will work', () => {
 it('Demo input change will work', () => {
   testUtil.setDOM();
 
-  let demo = new BasicDemo();
+  const demo = new BasicDemo();
 
   document.body.querySelector('.input').value = "test";
   document.body.querySelector('.input').dispatchEvent(new Event('input'));
@@ -51,7 +51,7 @@ it('Demo input change will work', () => {
 it('Demo handleShiftButton will work', () => {
   testUtil.setDOM();
 
-  let demo = new BasicDemo();
+  const demo = new BasicDemo();
 
   demo.keyboard.getButtonElement("{shift}")[0].onclick();
   expect(demo.keyboard.options.layoutName).toBe("shift");
diff --git a/src/demo/tests/ButtonThemeDemo.test.js b/src/demo/tests/ButtonThemeDemo.test.js
index 6f6773df..0a6d78a2 100644
--- a/src/demo/tests/ButtonThemeDemo.test.js
+++ b/src/demo/tests/ButtonThemeDemo.test.js
@@ -1,18 +1,18 @@
 import TestUtility from '../../utils/TestUtility';
 import ButtonThemeDemo from '../ButtonThemeDemo';
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('Demo will load', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  new ButtonThemeDemo();
 });
 
 it('Demo onDOMLoaded will work', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  const demo = new ButtonThemeDemo();
 
   expect(demo.keyboard).toBeTruthy();
 });
@@ -20,7 +20,7 @@ it('Demo onDOMLoaded will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  const demo = new ButtonThemeDemo();
 
   demo.onChange("test");
   
@@ -30,7 +30,7 @@ it('Demo onChange will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  const demo = new ButtonThemeDemo();
 
   demo.keyboard.getButtonElement("q").onclick();
   
@@ -40,7 +40,7 @@ it('Demo onChange will work', () => {
 it('Demo input change will work', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  const demo = new ButtonThemeDemo();
 
   document.body.querySelector('.input').value = "test";
   document.body.querySelector('.input').dispatchEvent(new Event('input'));
@@ -51,7 +51,7 @@ it('Demo input change will work', () => {
 it('Demo handleShiftButton will work', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  const demo = new ButtonThemeDemo();
 
   demo.keyboard.getButtonElement("{shift}")[0].onclick();
   expect(demo.keyboard.options.layoutName).toBe("shift");
@@ -63,15 +63,15 @@ it('Demo handleShiftButton will work', () => {
 it('Demo buttons will have proper attributes and classes', () => {
   testUtil.setDOM();
 
-  let demo = new ButtonThemeDemo();
+  const demo = new ButtonThemeDemo();
 
-  let buttonDOM = demo.keyboard.getButtonElement("b");
+  const buttonDOM = demo.keyboard.getButtonElement("b");
 
   console.log("buttonDOM", buttonDOM.outerHTML);
 
-  let hasAttribute = buttonDOM.hasAttribute("aria-label");
+  const hasAttribute = buttonDOM.hasAttribute("aria-label");
   expect(hasAttribute).toBeTruthy();
 
-  let hasClass = buttonDOM.classList.contains("my-button-outline");
+  const hasClass = buttonDOM.classList.contains("my-button-outline");
   expect(hasClass).toBeTruthy();
 });
\ No newline at end of file
diff --git a/src/demo/tests/FullKeyboardDemo.test.js b/src/demo/tests/FullKeyboardDemo.test.js
index 1d70f214..d9093198 100644
--- a/src/demo/tests/FullKeyboardDemo.test.js
+++ b/src/demo/tests/FullKeyboardDemo.test.js
@@ -1,18 +1,17 @@
 import TestUtility from '../../utils/TestUtility';
 import FullKeyboardDemo from '../FullKeyboardDemo';
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('Demo will load', () => {
   testUtil.setDOM();
-
-  let demo = new FullKeyboardDemo();
+  new FullKeyboardDemo();
 });
 
 it('Demo onDOMLoaded will work', () => {
   testUtil.setDOM();
 
-  let demo = new FullKeyboardDemo();
+  const demo = new FullKeyboardDemo();
 
   expect(demo.keyboard).toBeTruthy();
 });
@@ -20,7 +19,7 @@ it('Demo onDOMLoaded will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new FullKeyboardDemo();
+  const demo = new FullKeyboardDemo();
 
   demo.onChange("test");
   
@@ -30,7 +29,7 @@ it('Demo onChange will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new FullKeyboardDemo();
+  const demo = new FullKeyboardDemo();
 
   demo.keyboard.getButtonElement("q").onclick();
   
@@ -40,7 +39,7 @@ it('Demo onChange will work', () => {
 it('Demo input change will work', () => {
   testUtil.setDOM();
 
-  let demo = new FullKeyboardDemo();
+  const demo = new FullKeyboardDemo();
 
   document.body.querySelector('.input').value = "test";
   document.body.querySelector('.input').dispatchEvent(new Event('input'));
@@ -52,7 +51,7 @@ it('Demo input change will work', () => {
 it('Demo handleShiftButton will work', () => {
   testUtil.setDOM();
 
-  let demo = new FullKeyboardDemo();
+  const demo = new FullKeyboardDemo();
 
   demo.keyboard.getButtonElement("{shiftleft}").onclick();
   expect(demo.keyboard.options.layoutName).toBe("shift");
diff --git a/src/demo/tests/MultipleKeyboardsDestroyDemo.test.js b/src/demo/tests/MultipleKeyboardsDestroyDemo.test.js
index fc92dcf3..bc73bf59 100644
--- a/src/demo/tests/MultipleKeyboardsDestroyDemo.test.js
+++ b/src/demo/tests/MultipleKeyboardsDestroyDemo.test.js
@@ -3,18 +3,18 @@ import MultipleKeyboardsDestroyDemo from '../MultipleKeyboardsDestroyDemo';
 
 jest.useFakeTimers();
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('Demo will load', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  new MultipleKeyboardsDestroyDemo();
 });
 
 it('Demo onDOMLoaded will work', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  const demo = new MultipleKeyboardsDestroyDemo();
 
   expect(demo.keyboard).toBeTruthy();
 });
@@ -22,7 +22,7 @@ it('Demo onDOMLoaded will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  const demo = new MultipleKeyboardsDestroyDemo();
 
   demo.onChange("test");
   demo.keyboard2.getButtonElement("q").click();
@@ -34,7 +34,7 @@ it('Demo onChange will work', () => {
 it('Demo onChange will work', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  const demo = new MultipleKeyboardsDestroyDemo();
 
   demo.keyboard.getButtonElement("q").onclick();
   
@@ -44,7 +44,7 @@ it('Demo onChange will work', () => {
 it('Demo input change will work', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  const demo = new MultipleKeyboardsDestroyDemo();
 
   document.body.querySelector('.input').value = "test";
   document.body.querySelector('.input').dispatchEvent(new Event('input'));
@@ -59,7 +59,7 @@ it('Demo input change will work', () => {
 it('Demo handleShiftButton will work', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  const demo = new MultipleKeyboardsDestroyDemo();
 
   demo.keyboard.getButtonElement("{shift}")[0].onclick();
   expect(demo.keyboard.options.layoutName).toBe("shift");
@@ -71,7 +71,7 @@ it('Demo handleShiftButton will work', () => {
 it('MultipleKeyboardsDestroyDemo will run all timers', () => {
   testUtil.setDOM();
 
-  let demo = new MultipleKeyboardsDestroyDemo();
+  const demo = new MultipleKeyboardsDestroyDemo();
   jest.runAllTimers();
 
   expect(demo.keyboard.options.theme).toBe("hg-theme-default myTheme");
diff --git a/src/lib/components/tests/Keyboard.test.js b/src/lib/components/tests/Keyboard.test.js
index e268ae0c..e9d8d302 100644
--- a/src/lib/components/tests/Keyboard.test.js
+++ b/src/lib/components/tests/Keyboard.test.js
@@ -1,7 +1,7 @@
 import Keyboard from '../Keyboard';
 import TestUtility from '../../../utils/TestUtility';
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('Keyboard will not render without target element', () => {
   try {
@@ -38,7 +38,7 @@ it('Keyboard will run with custom DOM target', () => {
 it('Keyboard will run with debug option set', () => {
   testUtil.setDOM();
   
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true
   });
 
@@ -51,10 +51,10 @@ it('Keyboard will use touch events', () => {
   testUtil.clear()
 
   document.body.innerHTML = `
-    <div id="keyboard"></div>
+    <div class="keyboard"></div>
   `;
 
-  const keyboard = new Keyboard('#keyboard', {
+  const keyboard = new Keyboard('.keyboard', {
     useTouchEvents: true,
     onChange: () => touched = true,
     layout: {
@@ -73,7 +73,7 @@ it('Keyboard will use touch events', () => {
 
 it('Keyboard standard buttons will work', () => {
   testUtil.setDOM();
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: {
       "default": 10
     }
@@ -85,7 +85,7 @@ it('Keyboard standard buttons will work', () => {
 
 it('Keyboard shift buttons will work', () => {
   testUtil.setDOM();
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.setOptions({
     layoutName: "shift",
@@ -97,7 +97,7 @@ it('Keyboard shift buttons will work', () => {
 
 it('Keyboard setOptions will work without a param', () => {
   testUtil.setDOM();
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.setOptions();
 });
@@ -105,7 +105,7 @@ it('Keyboard setOptions will work without a param', () => {
 it('Keyboard empty buttons wont do anything as expected', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     layout: {
       default: [
         "{//} {button} d",
@@ -122,7 +122,7 @@ it('Keyboard onKeyPress will work', () => {
 
   let pressed = false;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     onKeyPress: () => {
       pressed = true;
     },
@@ -137,7 +137,7 @@ it('Keyboard onKeyPress will work', () => {
 it('Keyboard standard function buttons will not change input', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     useButtonTag: true
   });
 
@@ -158,7 +158,7 @@ it('Keyboard syncInstanceInputs will work', () => {
     <div class="keyboard2"></div>
   `;
 
-  let sharedOptions = {
+  const sharedOptions = {
     syncInstanceInputs: true
   };
 
@@ -195,7 +195,7 @@ it('Keyboard onChange will work', () => {
 
   let output = false;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     onChange: (input) => {
       output = input;
     },
@@ -212,7 +212,7 @@ it('Keyboard onChangeAll will work', () => {
 
   let output;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     onChangeAll: (input) => {
       output = input ? input.default : null;
     },
@@ -227,7 +227,7 @@ it('Keyboard onChangeAll will work', () => {
 it('Keyboard clearInput will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   /**
    * Avoid setInput for this test
@@ -249,12 +249,12 @@ it('Keyboard clearInput will work with syncInstanceInputs', () => {
     <div class="keyboard2"></div>
   `;
 
-  let sharedOptions = {
+  const sharedOptions = {
     syncInstanceInputs: true
   };
 
-  let keyboard1 = new Keyboard(".keyboard1", sharedOptions);
-  let keyboard2 = new Keyboard(".keyboard2", sharedOptions);
+  const keyboard1 = new Keyboard(".keyboard1", sharedOptions);
+  const keyboard2 = new Keyboard(".keyboard2", sharedOptions);
 
   /**
    * Avoid setInput for this test
@@ -271,7 +271,7 @@ it('Keyboard clearInput will work with syncInstanceInputs', () => {
 it('Keyboard setInput will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.setInput("hello");
 
@@ -286,12 +286,12 @@ it('Keyboard setInput will work with syncInstanceInputs', () => {
     <div class="keyboard2"></div>
   `;
 
-  let sharedOptions = {
+  const sharedOptions = {
     syncInstanceInputs: true
   };
 
-  let keyboard1 = new Keyboard(".keyboard1", sharedOptions);
-  let keyboard2 = new Keyboard(".keyboard2", sharedOptions);
+  const keyboard1 = new Keyboard(".keyboard1", sharedOptions);
+  const keyboard2 = new Keyboard(".keyboard2", sharedOptions);
 
   keyboard1.setInput("hello");
 
@@ -306,8 +306,8 @@ it('Keyboard dispatch will work', () => {
     <div class="keyboard2"></div>
   `;
 
-  let keyboard1 = new Keyboard(".keyboard1");
-  let keyboard2 = new Keyboard(".keyboard2");
+  const keyboard1 = new Keyboard(".keyboard1");
+  const keyboard2 = new Keyboard(".keyboard2");
 
   keyboard1.dispatch(instance => {
     instance.setOptions({
@@ -331,8 +331,8 @@ it('Keyboard dispatch will not work without SimpleKeyboardInstances', () => {
     <div class="keyboard2"></div>
   `;
 
-  let keyboard1 = new Keyboard(".keyboard1");
-  let keyboard2 = new Keyboard(".keyboard2");
+  const keyboard1 = new Keyboard(".keyboard1");
+  new Keyboard(".keyboard2");
 
   window['SimpleKeyboardInstances'] = null;
 
@@ -357,8 +357,8 @@ it('Keyboard dispatch will not work without SimpleKeyboardInstances', () => {
 it('Keyboard addButtonTheme will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
-  let returnVal = keyboard.addButtonTheme("q", "test");
+  const keyboard = new Keyboard();
+  keyboard.addButtonTheme("q", "test");
 
   expect(keyboard.options.buttonTheme[0].class).toBe("test");
 });
@@ -366,8 +366,8 @@ it('Keyboard addButtonTheme will work', () => {
 it('Keyboard addButtonTheme will not work without params', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
-  let returnVal = keyboard.addButtonTheme();
+  const keyboard = new Keyboard();
+  const returnVal = keyboard.addButtonTheme();
 
   expect(returnVal).toBeFalsy();
 });
@@ -375,7 +375,7 @@ it('Keyboard addButtonTheme will not work without params', () => {
 it('Keyboard addButtonTheme will amend a buttonTheme', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -392,7 +392,7 @@ it('Keyboard addButtonTheme will amend a buttonTheme', () => {
 it('Keyboard addButtonTheme will create a buttonTheme', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "blurb",
@@ -409,7 +409,7 @@ it('Keyboard addButtonTheme will create a buttonTheme', () => {
 it('Keyboard addButtonTheme will ignore a repeated buttonTheme', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -426,7 +426,7 @@ it('Keyboard addButtonTheme will ignore a repeated buttonTheme', () => {
 it('Keyboard addButtonTheme will amend a buttonTheme', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -444,7 +444,7 @@ it('Keyboard addButtonTheme will amend a buttonTheme', () => {
 it('Keyboard removeButtonTheme without params will remove all button themes', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -462,7 +462,7 @@ it('Keyboard removeButtonTheme without params will remove all button themes', ()
 it('Keyboard removeButtonTheme will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -479,7 +479,7 @@ it('Keyboard removeButtonTheme will work', () => {
 it('Keyboard removeButtonTheme will work wihtout a class', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -496,7 +496,7 @@ it('Keyboard removeButtonTheme will work wihtout a class', () => {
 it('Keyboard removeButtonTheme will do nothing without a button param', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -513,7 +513,7 @@ it('Keyboard removeButtonTheme will do nothing without a button param', () => {
 it('Keyboard removeButtonTheme does nothing if req button doesnt have a buttonTheme', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -530,7 +530,7 @@ it('Keyboard removeButtonTheme does nothing if req button doesnt have a buttonTh
 it('Keyboard removeButtonTheme does nothing if buttonTheme class does not exist', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "testy",
@@ -547,7 +547,7 @@ it('Keyboard removeButtonTheme does nothing if buttonTheme class does not exist'
 it('Keyboard removeButtonTheme does nothing if buttonTheme doesnt have the requested buttons', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -564,7 +564,7 @@ it('Keyboard removeButtonTheme does nothing if buttonTheme doesnt have the reque
 it('Keyboard getButtonElement will not return anything if empty match', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     layout: {
       default: [
         "{//} {button} d",
@@ -579,7 +579,7 @@ it('Keyboard getButtonElement will not return anything if empty match', () => {
 it('Keyboard getButtonElement will return multiple matched buttons', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   expect(keyboard.getButtonElement("{shift}").length).toBe(2);
 });
@@ -606,7 +606,7 @@ it('Keyboard will receive physical keyboard events', () => {
 it('Keyboard caretEventHandler will detect input, textarea focus', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.caretEventHandler({
     charCode: 0,
@@ -625,7 +625,7 @@ it('Keyboard caretEventHandler will detect input, textarea focus', () => {
 it('Keyboard caretEventHandler will not set caretPosition on disableCaretPositioning', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.caretEventHandler({
     charCode: 0,
@@ -661,7 +661,7 @@ it('Keyboard caretEventHandler will not set caretPosition on disableCaretPositio
 it('Keyboard caretEventHandler ignore positioning if input, textarea is blur', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.isMouseHold = true;
 
@@ -682,7 +682,7 @@ it('Keyboard caretEventHandler ignore positioning if input, textarea is blur', (
 it('Keyboard caretEventHandler will work with debug', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true
   });
 
@@ -705,7 +705,7 @@ it('Keyboard onInit will work', () => {
 
   let passed = false;
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     onInit: () => {
       passed = true
     }
@@ -719,7 +719,7 @@ it('Keyboard onRender will work', () => {
 
   let passed = false;
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     onRender: () => {
       passed = true
     }
@@ -731,7 +731,7 @@ it('Keyboard onRender will work', () => {
 it('Keyboard buttonTheme that is invalid will be ignored and not throw', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     buttonTheme: [
       {
         class: null,
@@ -744,7 +744,7 @@ it('Keyboard buttonTheme that is invalid will be ignored and not throw', () => {
 it('Keyboard buttonTheme buttons that are invalid will be ignored and not throw', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     buttonTheme: [
       {
         class: null,
@@ -772,7 +772,7 @@ it('Keyboard buttonTheme will be ignored if buttons param not a string', () => {
 it('Keyboard buttonTheme will be ignored if already added', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     buttonTheme: [
       {
         class: "test",
@@ -801,7 +801,7 @@ it('Keyboard buttonTheme will be ignored if already added', () => {
 it('Keyboard can set a module', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.registerModule(
     "test",
@@ -816,7 +816,7 @@ it('Keyboard can set a module', () => {
 it('Keyboard registerModule will return current module tree', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.modules.test = {
     testy: "test"
@@ -836,7 +836,7 @@ it('Keyboard registerModule will return current module tree', () => {
 it('Keyboard can set a module by amending the modules tree', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.modules = {
     testman: {
@@ -857,7 +857,7 @@ it('Keyboard can set a module by amending the modules tree', () => {
 it('Keyboard will not retrieve an option for an inexistent module', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   expect(keyboard.getModuleProp("test", "foo")).toBeFalsy();
 });
@@ -865,7 +865,7 @@ it('Keyboard will not retrieve an option for an inexistent module', () => {
 it('Keyboard will get a list of modules', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.registerModule(
     "test",
@@ -886,7 +886,7 @@ it('Keyboard loadModules will load a simple module', () => {
     };
   }
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     modules: [
       myClass
     ]
@@ -896,7 +896,7 @@ it('Keyboard loadModules will load a simple module', () => {
 it('Keyboard handleButtonMouseUp will set isMouseHold to false', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.isMouseHold = true;
 
@@ -908,7 +908,7 @@ it('Keyboard handleButtonMouseUp will set isMouseHold to false', () => {
 it('Keyboard handleButtonMouseUp clear holdInteractionTimeout', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.isMouseHold = true;
   keyboard.holdInteractionTimeout = setTimeout(() => {}, 10000);
@@ -919,7 +919,7 @@ it('Keyboard handleButtonMouseUp clear holdInteractionTimeout', () => {
 it('Keyboard handleButtonMouseDown will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.handleButtonMouseDown("q", {
     target: keyboard.getButtonElement("q"),
@@ -937,7 +937,7 @@ it('Keyboard handleButtonMouseDown will work', () => {
 it('Keyboard handleButtonMouseDown will work with preventMouseDownDefault', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.options.preventMouseDownDefault = true;
 
@@ -965,7 +965,7 @@ it('Keyboard onModulesLoaded will work', () => {
 
   let foo;
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     modules: [
       myClass
     ],
@@ -980,7 +980,7 @@ it('Keyboard onModulesLoaded will work', () => {
 it('Keyboard inputPattern will work globally', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     inputPattern: /^\d+$/,
     useMouseEvents: true
   });
@@ -997,7 +997,7 @@ it('Keyboard inputPattern will work globally', () => {
 it('Keyboard inputPattern will work by input name', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true,
     inputName: "test1",
     inputPattern: {
@@ -1026,7 +1026,7 @@ it('Keyboard processAutoTouchEvents will work', () => {
 
   navigator.maxTouchPoints = true;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     autoUseTouchEvents: true
   });
 
@@ -1038,7 +1038,7 @@ it('Keyboard processAutoTouchEvents will work with debugging enabled', () => {
 
   navigator.maxTouchPoints = true;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     autoUseTouchEvents: true,
     debug: true
   });
@@ -1051,7 +1051,7 @@ it('Keyboard beforeFirstRender method will work', () => {
 
   let timesCalled = 0;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     beforeFirstRender: () => {
       timesCalled++;
     }
@@ -1074,7 +1074,7 @@ it('Keyboard beforeFirstRender will show PointerEvents warning', () => {
 
   window.PointerEvent = window.PointerEvent ? window.PointerEvent : () => {};
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     debug: true,
     beforeFirstRender: () => {
       timesCalled++;
@@ -1089,7 +1089,7 @@ it('Keyboard beforeRender method will work', () => {
 
   let timesCalled = 0;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     beforeRender: () => {
       timesCalled++;
     }
@@ -1108,7 +1108,7 @@ it('Keyboard beforeRender method will work', () => {
 it('Keyboard parseRowDOMContainers will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     layout: {
       'default': [
         '` [1 2 3 4 5 6 7 8 9] 0 - = {bksp}',
@@ -1127,7 +1127,7 @@ it('Keyboard parseRowDOMContainers will work', () => {
     }
   });
 
-  let containers = Array.from(document.querySelectorAll(".hg-button-container"));
+  const containers = Array.from(document.querySelectorAll(".hg-button-container"));
 
   expect(containers.length).toBe(5);
 
@@ -1144,7 +1144,7 @@ it('Keyboard parseRowDOMContainers will ignore empty rows', () => {
   let failed = false;
 
   try {
-    let keyboard = new Keyboard();
+    const keyboard = new Keyboard();
     keyboard.parseRowDOMContainers({
       children: []
     });
@@ -1159,7 +1159,7 @@ it('Keyboard parseRowDOMContainers will ignore empty rows', () => {
 it('Keyboard parseRowDOMContainers will ignore missing endIndex or endIndex before startIndex', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     layout: {
       'default': [
         '` [1 2 3 4 5 6 7 8 9 0 - = {bksp}',
@@ -1168,7 +1168,7 @@ it('Keyboard parseRowDOMContainers will ignore missing endIndex or endIndex befo
     }
   });
 
-  let containers = Array.from(document.querySelectorAll(".hg-button-container"));
+  const containers = Array.from(document.querySelectorAll(".hg-button-container"));
 
   expect(containers.length).toBe(0);
 });
@@ -1176,7 +1176,7 @@ it('Keyboard parseRowDOMContainers will ignore missing endIndex or endIndex befo
 it('Keyboard disableRowButtonContainers will bypass parseRowDOMContainers', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     disableRowButtonContainers: true,
     layout: {
       'default': [
@@ -1196,7 +1196,7 @@ it('Keyboard disableRowButtonContainers will bypass parseRowDOMContainers', () =
     }
   });
 
-  let containers = Array.from(document.querySelectorAll(".hg-button-container"));
+  const containers = Array.from(document.querySelectorAll(".hg-button-container"));
 
   expect(containers.length).toBe(0);
 });
@@ -1204,7 +1204,7 @@ it('Keyboard disableRowButtonContainers will bypass parseRowDOMContainers', () =
 it('Keyboard inputName change will trigget caretPosition reset', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.caretPosition = 0;
 
@@ -1227,7 +1227,7 @@ it('Keyboard inputName change will trigget caretPosition reset', () => {
 it('Keyboard destroy will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
   keyboard.destroy();
   expect(keyboard.keyboardDOM.innerHTML).toBe("");
 });
@@ -1235,7 +1235,7 @@ it('Keyboard destroy will work', () => {
 it('Keyboard destroy will work with debug option', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({ debug: true });
+  const keyboard = new Keyboard({ debug: true });
   keyboard.destroy();
   expect(keyboard.keyboardDOM.innerHTML).toBe("");
 });
@@ -1243,7 +1243,7 @@ it('Keyboard destroy will work with debug option', () => {
 it('Keyboard disableButtonHold will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     disableButtonHold: true
   });
 
@@ -1253,7 +1253,7 @@ it('Keyboard disableButtonHold will work', () => {
 it('Keyboard caretEventHandler will be triggered on mouseup and ontouchend', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     disableCaretPositioning: true
   });
 
@@ -1289,7 +1289,7 @@ it('Keyboard onKeyReleased will work', () => {
   let firedTimes = 0;
   let buttonPressed;
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     onKeyReleased: button => {
       pressed = true;
       buttonPressed = button;
@@ -1309,7 +1309,7 @@ it('Keyboard onKeyReleased will work', () => {
 it('Keyboard buttonAttribute will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     buttonAttributes: [
       {
         attribute: "aria-label",
@@ -1323,7 +1323,7 @@ it('Keyboard buttonAttribute will work', () => {
 it('Keyboard buttonAttribute will warn about invalid entries', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     buttonAttributes: [
       {
         attribute: false,
@@ -1335,6 +1335,6 @@ it('Keyboard buttonAttribute will warn about invalid entries', () => {
 
 it('Keyboard recurseButtons will not work without a valid param', () => {
   testUtil.setDOM();
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
   expect(keyboard.recurseButtons()).toBe(false);
 });
diff --git a/src/lib/services/KeyboardLayout.js b/src/lib/services/KeyboardLayout.js
index 4c0ccd6e..fe437589 100644
--- a/src/lib/services/KeyboardLayout.js
+++ b/src/lib/services/KeyboardLayout.js
@@ -1,29 +1,18 @@
-/**
- * Keyboard Layout Service
- */
-class KeyboardLayout {
-  /**
-   * Get default simple-keyboard layout
-   * @return {object} The default layout (US-QWERTY)
-   */
-  static getDefaultLayout() {
-    return {
-      default: [
-        "` 1 2 3 4 5 6 7 8 9 0 - = {bksp}",
-        "{tab} q w e r t y u i o p [ ] \\",
-        "{lock} a s d f g h j k l ; ' {enter}",
-        "{shift} z x c v b n m , . / {shift}",
-        ".com @ {space}"
-      ],
-      shift: [
-        "~ ! @ # $ % ^ & * ( ) _ + {bksp}",
-        "{tab} Q W E R T Y U I O P { } |",
-        '{lock} A S D F G H J K L : " {enter}',
-        "{shift} Z X C V B N M < > ? {shift}",
-        ".com @ {space}"
-      ]
-    };
-  }
-}
-
-export default KeyboardLayout;
+export const getDefaultLayout = () => {
+  return {
+    default: [
+      "` 1 2 3 4 5 6 7 8 9 0 - = {bksp}",
+      "{tab} q w e r t y u i o p [ ] \\",
+      "{lock} a s d f g h j k l ; ' {enter}",
+      "{shift} z x c v b n m , . / {shift}",
+      ".com @ {space}"
+    ],
+    shift: [
+      "~ ! @ # $ % ^ & * ( ) _ + {bksp}",
+      "{tab} Q W E R T Y U I O P { } |",
+      '{lock} A S D F G H J K L : " {enter}',
+      "{shift} Z X C V B N M < > ? {shift}",
+      ".com @ {space}"
+    ]
+  };
+};
diff --git a/src/lib/services/PhysicalKeyboard.js b/src/lib/services/PhysicalKeyboard.js
index ca713783..9dae50b5 100644
--- a/src/lib/services/PhysicalKeyboard.js
+++ b/src/lib/services/PhysicalKeyboard.js
@@ -21,11 +21,11 @@ class PhysicalKeyboard {
   }
 
   handleHighlightKeyDown(event) {
-    let options = this.getOptions();
-    let buttonPressed = this.getSimpleKeyboardLayoutKey(event);
+    const options = this.getOptions();
+    const buttonPressed = this.getSimpleKeyboardLayoutKey(event);
 
     this.dispatch(instance => {
-      let buttonDOM =
+      const buttonDOM =
         instance.getButtonElement(buttonPressed) ||
         instance.getButtonElement(`{${buttonPressed}}`);
 
@@ -39,10 +39,10 @@ class PhysicalKeyboard {
   }
 
   handleHighlightKeyUp(event) {
-    let buttonPressed = this.getSimpleKeyboardLayoutKey(event);
+    const buttonPressed = this.getSimpleKeyboardLayoutKey(event);
 
     this.dispatch(instance => {
-      let buttonDOM =
+      const buttonDOM =
         instance.getButtonElement(buttonPressed) ||
         instance.getButtonElement(`{${buttonPressed}}`);
 
diff --git a/src/lib/services/tests/PhysicalKeyboard.test.js b/src/lib/services/tests/PhysicalKeyboard.test.js
index 857868a2..53bec9af 100644
--- a/src/lib/services/tests/PhysicalKeyboard.test.js
+++ b/src/lib/services/tests/PhysicalKeyboard.test.js
@@ -1,12 +1,12 @@
 import Keyboard from '../../components/Keyboard';
 import TestUtility from '../../../utils/TestUtility';
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('PhysicalKeyboard keydown will be handled with physicalKeyboardHighlight', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: true
   });
 
@@ -22,7 +22,7 @@ it('PhysicalKeyboard keydown will be handled with physicalKeyboardHighlight', ()
 it('PhysicalKeyboard keydown will be handled without physicalKeyboardHighlight', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: false
   });
 
@@ -38,7 +38,7 @@ it('PhysicalKeyboard keydown will be handled without physicalKeyboardHighlight',
 it('PhysicalKeyboard keydown will not style non-existent buttons', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: true
   });
 
@@ -54,7 +54,7 @@ it('PhysicalKeyboard keydown will not style non-existent buttons', () => {
 it('PhysicalKeyboard keyup will be handled with physicalKeyboardHighlight', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: true
   });
 
@@ -70,7 +70,7 @@ it('PhysicalKeyboard keyup will be handled with physicalKeyboardHighlight', () =
 it('PhysicalKeyboard keyup will be handle special buttons', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: true
   });
 
@@ -86,7 +86,7 @@ it('PhysicalKeyboard keyup will be handle special buttons', () => {
 it('PhysicalKeyboard keyup will not style non-existent buttons', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: true,
     debug: true
   });
@@ -103,7 +103,7 @@ it('PhysicalKeyboard keyup will not style non-existent buttons', () => {
 it('PhysicalKeyboard will work with F1-F12 keys', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  new Keyboard({
     physicalKeyboardHighlight: true,
     debug: true
   });
diff --git a/src/lib/services/tests/Utilities.test.js b/src/lib/services/tests/Utilities.test.js
index 35a1e43c..67d3b305 100644
--- a/src/lib/services/tests/Utilities.test.js
+++ b/src/lib/services/tests/Utilities.test.js
@@ -1,12 +1,12 @@
 import Keyboard from '../../components/Keyboard';
 import TestUtility from '../../../utils/TestUtility';
 
-let testUtil = new TestUtility();
+const testUtil = new TestUtility();
 
 it('Keyboard mergeDisplay will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     mergeDisplay: true,
     display: {
       "q": "qreplaced"
@@ -29,9 +29,9 @@ it('Keyboard function buttons will work', () => {
 it('Keyboard {bksp} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{bksp}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{bksp}", "test");
   
   expect(output).toBe("tes");
 });
@@ -39,9 +39,9 @@ it('Keyboard {bksp} button will work', () => {
 it('Keyboard {space} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{space}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{space}", "test");
   
   expect(output).toBe("test ");
 });
@@ -49,9 +49,9 @@ it('Keyboard {space} button will work', () => {
 it('Keyboard {tab} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{tab}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{tab}", "test");
   
   expect(output).toBe("test\t");
 });
@@ -59,11 +59,11 @@ it('Keyboard {tab} button will work', () => {
 it('Keyboard {tab} button will work with tabCharOnTab:false', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     tabCharOnTab: false
   });
 
-  let output = keyboard.utilities.getUpdatedInput("{tab}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{tab}", "test");
   
   expect(output).toBe("test");
 });
@@ -71,9 +71,9 @@ it('Keyboard {tab} button will work with tabCharOnTab:false', () => {
 it('Keyboard {enter} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{enter}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{enter}", "test");
   
   expect(output).toBe("test");
 });
@@ -81,11 +81,11 @@ it('Keyboard {enter} button will work', () => {
 it('Keyboard {enter} button will work with newLineOnEnter:true', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     newLineOnEnter: true
   });
 
-  let output = keyboard.utilities.getUpdatedInput("{enter}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{enter}", "test");
   
   expect(output).toBe("test\n");
 });
@@ -93,10 +93,10 @@ it('Keyboard {enter} button will work with newLineOnEnter:true', () => {
 it('Keyboard {numpadX} buttons will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   for(let i = 0;i<=9;i++){
-    let output = keyboard.utilities.getUpdatedInput(`{numpad${i}}`, "test");
+    const output = keyboard.utilities.getUpdatedInput(`{numpad${i}}`, "test");
     expect(output).toBe(`test${i}`);
   }
 });
@@ -104,9 +104,9 @@ it('Keyboard {numpadX} buttons will work', () => {
 it('Keyboard {numpaddivide} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{numpaddivide}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{numpaddivide}", "test");
   
   expect(output).toBe("test/");
 });
@@ -114,9 +114,9 @@ it('Keyboard {numpaddivide} button will work', () => {
 it('Keyboard {numpadmultiply} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{numpadmultiply}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{numpadmultiply}", "test");
   
   expect(output).toBe("test*");
 });
@@ -124,9 +124,9 @@ it('Keyboard {numpadmultiply} button will work', () => {
 it('Keyboard {numpadsubtract} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{numpadsubtract}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{numpadsubtract}", "test");
   
   expect(output).toBe("test-");
 });
@@ -134,9 +134,9 @@ it('Keyboard {numpadsubtract} button will work', () => {
 it('Keyboard {numpadadd} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{numpadadd}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{numpadadd}", "test");
   
   expect(output).toBe("test+");
 });
@@ -144,9 +144,9 @@ it('Keyboard {numpadadd} button will work', () => {
 it('Keyboard {numpadadd} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{numpadadd}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{numpadadd}", "test");
   
   expect(output).toBe("test+");
 });
@@ -154,9 +154,9 @@ it('Keyboard {numpadadd} button will work', () => {
 it('Keyboard {numpaddecimal} button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{numpaddecimal}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{numpaddecimal}", "test");
   
   expect(output).toBe("test.");
 });
@@ -164,7 +164,7 @@ it('Keyboard {numpaddecimal} button will work', () => {
 it('Keyboard custom function buttons will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     layout: {
       default: [
         "{randombuttontest}"
@@ -172,7 +172,7 @@ it('Keyboard custom function buttons will work', () => {
     }
   });
 
-  let output = keyboard.utilities.getUpdatedInput("{randombuttontest}", "test");
+  const output = keyboard.utilities.getUpdatedInput("{randombuttontest}", "test");
   
   expect(output).toBe("test");
   expect(keyboard.getButtonElement("{randombuttontest}").onclick).toBeTruthy();
@@ -181,9 +181,9 @@ it('Keyboard custom function buttons will work', () => {
 it('Keyboard "{" button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("{", "test");
+  const output = keyboard.utilities.getUpdatedInput("{", "test");
   
   expect(output).toBe("test{");
 });
@@ -191,9 +191,9 @@ it('Keyboard "{" button will work', () => {
 it('Keyboard "}" button will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
-  let output = keyboard.utilities.getUpdatedInput("}", "test");
+  const output = keyboard.utilities.getUpdatedInput("}", "test");
   
   expect(output).toBe("test}");
 });
@@ -201,11 +201,11 @@ it('Keyboard "}" button will work', () => {
 it('Keyboard standard button will affect input', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   for (let i = 65; i <= 90; i++) {
-    let char = String.fromCharCode(i);
-    let output = keyboard.utilities.getUpdatedInput(char, "test");
+    const char = String.fromCharCode(i);
+    const output = keyboard.utilities.getUpdatedInput(char, "test");
     expect(output).toBe(`test${char}`);
   }
 });
@@ -213,7 +213,7 @@ it('Keyboard standard button will affect input', () => {
 it('Keyboard updateCaretPos will work with minus', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     syncInstanceInputs: true
   });
 
@@ -226,7 +226,7 @@ it('Keyboard updateCaretPos will work with minus', () => {
 it('Keyboard updateCaretPos will work with minus', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.caretPosition = 5;
   keyboard.utilities.updateCaretPos(2, true);
@@ -237,7 +237,7 @@ it('Keyboard updateCaretPos will work with minus', () => {
 it('Keyboard updateCaretPos will work with plus', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.caretPosition = 5;
   keyboard.utilities.updateCaretPos(2);
@@ -248,7 +248,7 @@ it('Keyboard updateCaretPos will work with plus', () => {
 it('Keyboard addStringAt will work with debug', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true
   });
 
@@ -260,7 +260,7 @@ it('Keyboard addStringAt will work with debug', () => {
 it('Keyboard addStringAt will work with position', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true
   });
 
@@ -275,7 +275,7 @@ it('Keyboard addStringAt will work with position', () => {
 it('Keyboard addStringAt will respect maxLength', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true,
     maxLength: 4
   });
@@ -292,13 +292,13 @@ it('Keyboard addStringAt will respect maxLength', () => {
 it('Keyboard handleMaxLength will exit out on same updatedInput', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true
   });
 
   keyboard.setInput("test");
 
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "test")
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "test")
 
   expect(output).toBeFalsy();
 });
@@ -306,7 +306,7 @@ it('Keyboard handleMaxLength will exit out on same updatedInput', () => {
 it('Keyboard handleMaxLength will work with object maxLength', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: {
       default: 4
     }
@@ -314,7 +314,7 @@ it('Keyboard handleMaxLength will work with object maxLength', () => {
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBeTruthy();
 });
@@ -322,7 +322,7 @@ it('Keyboard handleMaxLength will work with object maxLength', () => {
 it('Keyboard handleMaxLength will work with object maxLength and debug', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: {
       default: 4
     },
@@ -331,7 +331,7 @@ it('Keyboard handleMaxLength will work with object maxLength and debug', () => {
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBeTruthy();
 });
@@ -339,7 +339,7 @@ it('Keyboard handleMaxLength will work with object maxLength and debug', () => {
 it('Keyboard handleMaxLength will return false if obj maxLength not reached', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: {
       default: 7
     }
@@ -347,7 +347,7 @@ it('Keyboard handleMaxLength will return false if obj maxLength not reached', ()
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBeFalsy();
 });
@@ -356,13 +356,13 @@ it('Keyboard handleMaxLength will return false if obj maxLength not reached', ()
 it('Keyboard handleMaxLength will work without debug', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: 4
   });
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBeTruthy();
 });
@@ -371,13 +371,13 @@ it('Keyboard handleMaxLength will work without debug', () => {
 it('Keyboard handleMaxLength will work with numeric maxLength', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: 3
   });
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBe(true);
 });
@@ -385,13 +385,13 @@ it('Keyboard handleMaxLength will work with numeric maxLength', () => {
 it('Keyboard handleMaxLength wont work with non numeric or object maxLength', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: "wrong"
   });
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBeFalsy();
 });
@@ -399,14 +399,14 @@ it('Keyboard handleMaxLength wont work with non numeric or object maxLength', ()
 it('Keyboard handleMaxLength wont work with non numeric or object maxLength (with debug)', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: "wrong",
     debug: true
   });
 
   keyboard.setInput("test");
   
-  let output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
+  const output = keyboard.utilities.handleMaxLength(keyboard.input, "testq");
 
   expect(output).toBeFalsy();
 });
@@ -414,11 +414,11 @@ it('Keyboard handleMaxLength wont work with non numeric or object maxLength (wit
 it('Keyboard isMaxLengthReached will work', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     maxLength: 5
   });
 
-  let output = keyboard.utilities.isMaxLengthReached();
+  const output = keyboard.utilities.isMaxLengthReached();
 
   expect(output).toBeFalsy();
 });
@@ -426,7 +426,7 @@ it('Keyboard isMaxLengthReached will work', () => {
 it('Keyboard removeAt will exit out on caretPosition:0', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.setInput("test");
   keyboard.caretPosition = 0;
@@ -442,7 +442,7 @@ it('Keyboard removeAt will exit out on caretPosition:0', () => {
 it('Keyboard removeAt will remove multi-byte unicodes with caretPos>0', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
 
   keyboard.caretPosition = 6;
   let output = keyboard.utilities.removeAt("test\uD83D\uDE00", 6);
@@ -456,7 +456,7 @@ it('Keyboard removeAt will remove multi-byte unicodes with caretPos>0', () => {
 it('Keyboard removeAt will not remove multi-byte unicodes with caretPos:0', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
   let output = keyboard.utilities.removeAt("\uD83D\uDE00");
   expect(output).toBeFalsy();
 
@@ -467,7 +467,7 @@ it('Keyboard removeAt will not remove multi-byte unicodes with caretPos:0', () =
 it('Keyboard removeAt will remove regular strings', () => {
   testUtil.setDOM();
 
-  let keyboard = new Keyboard({
+  const keyboard = new Keyboard({
     debug: true
   });
 
@@ -482,12 +482,12 @@ it('Keyboard removeAt will remove regular strings', () => {
 
 it('Keyboard will work with custom (and weird) class', () => {
   testUtil.setDOM("my--weird--class");
-  let keyboard = new Keyboard(".my--weird--class");
+  const keyboard = new Keyboard(".my--weird--class");
   expect(keyboard.keyboardDOMClass).toBe("my--weird--class");
 });
 
 it('Keyboard camelCase will work with empty strings', () => {
   testUtil.setDOM();
-  let keyboard = new Keyboard();
+  const keyboard = new Keyboard();
   expect(keyboard.utilities.camelCase()).toBeFalsy();
 });