diff --git a/src/constants.js b/src/constants.js
index cb25d0b..3fda96e 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -26,6 +26,6 @@ export const SIMPLE_MODAL_OPTIONS = {
   },
   styleContent: {
     padding: '0px',
-    overflow: 'visible', // needed for select box dropdowns which are larger than the modal
+    overflow: 'visible' // needed for select box dropdowns which are larger than the modal
   }
 }
diff --git a/src/logic/documentState.js b/src/logic/documentState.js
index 7d0afc0..f4cbb33 100644
--- a/src/logic/documentState.js
+++ b/src/logic/documentState.js
@@ -198,7 +198,7 @@ export function patchProps (state, operations) {
   return updatedState
 }
 
-export function getNextKeys(props, key, includeKey = false) {
+export function getNextKeys (props, key, includeKey = false) {
   if (props) {
     const index = props.findIndex(prop => prop.key === key)
     if (index !== -1) {
diff --git a/src/logic/documentState.test.js b/src/logic/documentState.test.js
index fe1b3c8..1b30331 100644
--- a/src/logic/documentState.test.js
+++ b/src/logic/documentState.test.js
@@ -10,8 +10,8 @@ import { syncState, updateProps } from './documentState.js'
 describe('documentState', () => {
   it('syncState', () => {
     const document = {
-      array: [1, 2, {c: 6}],
-      object: {a: 4, b: 5},
+      array: [1, 2, { c: 6 }],
+      object: { a: 4, b: 5 },
       value: 'hello'
     }
 
@@ -23,10 +23,10 @@ describe('documentState', () => {
 
     const expectedState = {}
     expectedState[STATE_EXPANDED] = true
-    expectedState[STATE_PROPS] =  [
-      { 'id': state[STATE_PROPS][0].id, 'key': 'array' },
-      { 'id': state[STATE_PROPS][1].id, 'key': 'object' },
-      { 'id': state[STATE_PROPS][2].id, 'key': 'value' }
+    expectedState[STATE_PROPS] = [
+      { id: state[STATE_PROPS][0].id, key: 'array' },
+      { id: state[STATE_PROPS][1].id, key: 'object' },
+      { id: state[STATE_PROPS][2].id, key: 'value' }
     ]
     expectedState.array = []
     expectedState.array[STATE_EXPANDED] = true
@@ -34,30 +34,30 @@ describe('documentState', () => {
     expectedState.array[2] = {}
     expectedState.array[2][STATE_EXPANDED] = false
     expectedState.array[2][STATE_PROPS] = [
-      { 'id': state.array[2][STATE_PROPS][0].id, 'key': 'c' } // FIXME: props should not be created because node is not expanded
+      { id: state.array[2][STATE_PROPS][0].id, key: 'c' } // FIXME: props should not be created because node is not expanded
     ]
     expectedState.object = {}
     expectedState.object[STATE_EXPANDED] = true
-    expectedState.object[STATE_PROPS] =  [
-      { 'id': state.object[STATE_PROPS][0].id, 'key': 'a' },
-      { 'id': state.object[STATE_PROPS][1].id, 'key': 'b' }
+    expectedState.object[STATE_PROPS] = [
+      { id: state.object[STATE_PROPS][0].id, key: 'a' },
+      { id: state.object[STATE_PROPS][1].id, key: 'b' }
     ]
 
     assert.deepStrictEqual(state, expectedState)
   })
 
   it('updateProps (1)', () => {
-    const props1 = updateProps({b: 2})
+    const props1 = updateProps({ b: 2 })
     assert.deepStrictEqual(props1.map(item => item.key), ['b'])
 
-    const props2 = updateProps({a: 1, b: 2}, props1)
+    const props2 = updateProps({ a: 1, b: 2 }, props1)
     assert.deepStrictEqual(props2.map(item => item.key), ['b', 'a'])
     assert.deepStrictEqual(props2[0], props1[0]) // b must still have the same id
   })
 
   it('updateProps (2)', () => {
-    const props1 = updateProps({a: 1, b: 2})
-    const props2 = updateProps({a: 1, b: 2}, props1)
+    const props1 = updateProps({ a: 1, b: 2 })
+    const props2 = updateProps({ a: 1, b: 2 }, props1)
     assert.deepStrictEqual(props2, props1)
   })
 
diff --git a/src/logic/history.js b/src/logic/history.js
index 99d37b5..1464c8e 100644
--- a/src/logic/history.js
+++ b/src/logic/history.js
@@ -113,4 +113,4 @@ export function createHistory (options = {}) {
     undo,
     redo
   }
-}
\ No newline at end of file
+}
diff --git a/src/logic/operations.js b/src/logic/operations.js
index d1a834a..e4ec7a8 100644
--- a/src/logic/operations.js
+++ b/src/logic/operations.js
@@ -22,7 +22,7 @@ import { isObjectOrArray } from '../utils/typeUtils.js'
  *                              key will maintain it's position above these keys
  * @return {JSONPatchDocument}
  */
-export function insertBefore (json, path, values, nextKeys) {  // TODO: find a better name and define datastructure for values
+export function insertBefore (json, path, values, nextKeys) { // TODO: find a better name and define datastructure for values
   const parentPath = initial(path)
   const parent = getIn(json, parentPath)
 
@@ -33,8 +33,7 @@ export function insertBefore (json, path, values, nextKeys) {  // TODO: find a b
       path: compileJSONPointer(parentPath.concat(offset + index)),
       value: entry.value
     }))
-  }
-  else { // 'object'
+  } else { // 'object'
     return [
       // insert new values
       ...values.map(entry => {
@@ -65,7 +64,7 @@ export function insertBefore (json, path, values, nextKeys) {  // TODO: find a b
  * @param {Array.<{key?: string, value: JSON}>} values
  * @return {JSONPatchDocument}
  */
-export function append (json, path, values) {  // TODO: find a better name and define datastructure for values
+export function append (json, path, values) { // TODO: find a better name and define datastructure for values
   const parent = getIn(json, path)
 
   if (Array.isArray(parent)) {
@@ -75,8 +74,7 @@ export function append (json, path, values) {  // TODO: find a better name and d
       path: compileJSONPointer(path.concat(offset + index)),
       value: entry.value
     }))
-  }
-  else { // 'object'
+  } else { // 'object'
     return values.map(entry => {
       const newProp = findUniqueName(entry.key, parent)
       return {
@@ -100,7 +98,7 @@ export function append (json, path, values) {  // TODO: find a better name and d
  *                              key will maintain it's position above these keys
  * @returns {JSONPatchDocument}
  */
-export function rename(parentPath, oldKey, newKey, nextKeys) {
+export function rename (parentPath, oldKey, newKey, nextKeys) {
   return [
     // rename a key
     {
@@ -129,7 +127,7 @@ export function rename(parentPath, oldKey, newKey, nextKeys) {
  *                              key will maintain it's position above these keys
  * @return {JSONPatchDocument}
  */
-export function replace (json, paths, values, nextKeys) {  // TODO: find a better name and define datastructure for values
+export function replace (json, paths, values, nextKeys) { // TODO: find a better name and define datastructure for values
   const firstPath = first(paths)
   const parentPath = initial(firstPath)
   const parent = getIn(json, parentPath)
@@ -149,8 +147,7 @@ export function replace (json, paths, values, nextKeys) {  // TODO: find a bette
         value: entry.value
       }))
     ]
-  }
-  else { // parent is Object
+  } else { // parent is Object
     // if we're going to replace an existing object with key "a" with a new
     // key "a", we must not create a new unique name "a (copy)".
     const removeKeys = new Set(paths.map(path => last(path)))
@@ -191,13 +188,13 @@ export function replace (json, paths, values, nextKeys) {  // TODO: find a bette
  */
 export function duplicate (doc, state, paths) {
   // FIXME: here we assume selection.paths is sorted correctly, that's a dangerous assumption
-  const lastPath = last(paths) 
+  const lastPath = last(paths)
   const parentPath = initial(lastPath)
   const beforeKey = last(lastPath)
   const props = getIn(state, parentPath.concat(STATE_PROPS))
   const nextKeys = getNextKeys(props, beforeKey, false)
   const parent = getIn(doc, parentPath)
-  
+
   if (Array.isArray(parent)) {
     const lastPath = last(paths)
     const offset = lastPath ? (parseInt(last(lastPath), 10) + 1) : 0
@@ -243,7 +240,7 @@ export function insert (doc, state, selection, values) {
     const nextKeys = getNextKeys(props, beforeKey, true)
     const operations = insertBefore(doc, selection.beforePath, values, nextKeys)
     // TODO: move calculation of nextKeys inside insertBefore?
-    
+
     return operations
   } else if (selection.appendPath) {
     const operations = append(doc, selection.appendPath, values)
@@ -257,23 +254,23 @@ export function insert (doc, state, selection, values) {
     const nextKeys = getNextKeys(props, beforeKey, true)
     const operations = replace(doc, selection.paths, values, nextKeys)
     // TODO: move calculation of nextKeys inside replace?
-    
+
     return operations
   }
 }
 
 export function createNewValue (doc, selection, type) {
   switch (type) {
-    case 'value': 
+    case 'value':
       return ''
-    
-    case 'object': 
+
+    case 'object':
       return {}
-    
-    case 'array': 
+
+    case 'array':
       return []
 
-    case 'structure': 
+    case 'structure':
       const parentPath = getParentPath(selection)
       const parent = getIn(doc, parentPath)
 
@@ -281,8 +278,8 @@ export function createNewValue (doc, selection, type) {
         const jsonExample = first(parent)
         const structure = cloneDeepWith(jsonExample, (value) => {
           return isObjectOrArray(value)
-              ? undefined // leave as is
-              : ''
+            ? undefined // leave as is
+            : ''
         })
 
         console.log('structure', jsonExample, structure)
@@ -316,16 +313,16 @@ export function remove (path) {
  */
 export function removeAll (paths) {
   return paths
-      .map(path => ({
-        op: 'remove',
-        path: compileJSONPointer(path)
-      }))
-      .reverse() // reverse is needed for arrays: delete the last index first
+    .map(path => ({
+      op: 'remove',
+      path: compileJSONPointer(path)
+    }))
+    .reverse() // reverse is needed for arrays: delete the last index first
 }
 
 // helper function to move a key down in an object,
 // so another key can get positioned before the moved down keys
-function moveDown(parentPath, key) {
+function moveDown (parentPath, key) {
   return {
     op: 'move',
     from: compileJSONPointer(parentPath.concat(key)),
diff --git a/src/logic/search.js b/src/logic/search.js
index 606bbce..a654c9b 100644
--- a/src/logic/search.js
+++ b/src/logic/search.js
@@ -3,7 +3,6 @@ import { STATE_SEARCH_PROPERTY, STATE_SEARCH_VALUE } from '../constants.js'
 import { existsIn, setIn } from '../utils/immutabilityHelpers.js'
 import { valueType } from '../utils/typeUtils.js'
 
-
 /**
  * @typedef {{path: Path, what: Symbol}} SearchItem
  */
@@ -101,7 +100,7 @@ export function searchPrevious (searchResult) {
 }
 
 function searchRecursive (key, doc, searchText) {
-  let results = undefined
+  let results
 
   if (typeof key === 'string' && containsCaseInsensitive(key, searchText)) {
     results = createOrAdd(results, STATE_SEARCH_PROPERTY, 'search')
@@ -110,14 +109,14 @@ function searchRecursive (key, doc, searchText) {
   const type = valueType(doc)
   if (type === 'array') {
     doc.forEach((item, index) => {
-      let childResults = searchRecursive(index, item, searchText)
+      const childResults = searchRecursive(index, item, searchText)
       if (childResults) {
         results = createOrAdd(results, index, childResults)
       }
     })
   } else if (type === 'object') {
     Object.keys(doc).forEach(prop => {
-      let childResults = searchRecursive(prop, doc[prop], searchText)
+      const childResults = searchRecursive(prop, doc[prop], searchText)
       if (childResults) {
         results = createOrAdd(results, prop, childResults)
       }
@@ -167,7 +166,7 @@ function flattenSearch (searchResult) {
   return resultArray
 }
 
-function createOrAdd(object, key, value) {
+function createOrAdd (object, key, value) {
   if (object) {
     object[key] = value
     return object
diff --git a/src/logic/validation.js b/src/logic/validation.js
index 5b1ec3d..dc68bee 100644
--- a/src/logic/validation.js
+++ b/src/logic/validation.js
@@ -3,14 +3,14 @@ import { VALIDATION_ERROR } from '../constants.js'
 import { existsIn, setIn } from '../utils/immutabilityHelpers.js'
 
 /**
- * Create a nested map with validation errors, 
+ * Create a nested map with validation errors,
  * and also create error messages for the parent nodes of the nodes having an error.
- * 
+ *
  * @param {ValidationError[]} validationErrors
- * @return {Object.<string, string> | undefined} Returns a nested object containing  
+ * @return {Object.<string, string> | undefined} Returns a nested object containing
  */
 export function mapValidationErrors (validationErrors) {
-  let object = undefined
+  let object
 
   validationErrors.forEach(validationError => {
     const errorPath = validationError.path.concat([VALIDATION_ERROR])
diff --git a/src/logic/validation.test.js b/src/logic/validation.test.js
index cc782b0..cf10ef7 100644
--- a/src/logic/validation.test.js
+++ b/src/logic/validation.test.js
@@ -30,7 +30,7 @@ describe('validation', () => {
     expected[VALIDATION_ERROR] = { isChildError: true, path: [], message: message3 }
     expected.pupils[VALIDATION_ERROR] = { isChildError: true, path: ['pupils'], message: message3 }
     expected.pupils[2][VALIDATION_ERROR] = { isChildError: true, path: ['pupils', 2], message: message3 }
-    
+
     const actual = mapValidationErrors(validationErrorsList)
 
     assert.deepStrictEqual(actual, expected)
@@ -51,9 +51,9 @@ describe('validation', () => {
       },
       [VALIDATION_ERROR]: error2
     }
-    
+
     const actual = mapValidationErrors(validationErrorsList)
 
     assert.deepStrictEqual(actual, expected)
   })
-})
\ No newline at end of file
+})
diff --git a/src/utils/arrayUtils.js b/src/utils/arrayUtils.js
index 9f06b69..90e380f 100644
--- a/src/utils/arrayUtils.js
+++ b/src/utils/arrayUtils.js
@@ -1,5 +1,5 @@
 import { isObject } from './typeUtils.js'
-import { compileJSONPointer, parseJSONPointer } from './jsonPointer.js' 
+import { compileJSONPointer, parseJSONPointer } from './jsonPointer.js'
 
 const MAX_ITEM_PATHS_COLLECTION = 10000
 const EMPTY_ARRAY = []
@@ -51,7 +51,7 @@ export function strictShallowEqual (a, b) {
   return true
 }
 
-export function compareArrays(a, b) {
+export function compareArrays (a, b) {
   const minLength = Math.min(a.length, b.length)
 
   for (let i = 0; i < minLength; i++) {
@@ -75,7 +75,7 @@ export function compareArrays(a, b) {
  */
 export function getNestedPaths (array, includeObjects = false) {
   const pathsMap = {}
-  
+
   if (!Array.isArray(array)) {
     throw new TypeError('Array expected')
   }
diff --git a/src/utils/arrayUtils.test.js b/src/utils/arrayUtils.test.js
index b6714fa..4cfe4dd 100644
--- a/src/utils/arrayUtils.test.js
+++ b/src/utils/arrayUtils.test.js
@@ -1,4 +1,4 @@
-import assert from "assert"
+import assert from 'assert'
 import { compareArrays, getNestedPaths } from './arrayUtils.js'
 
 describe('arrayUtils', () => {
diff --git a/src/utils/domUtils.js b/src/utils/domUtils.js
index 6473ee4..aa8f9e8 100644
--- a/src/utils/domUtils.js
+++ b/src/utils/domUtils.js
@@ -5,7 +5,7 @@
  * @param {Element} element  An HTML DOM element like a DIV
  * @return {string}
  */
-export function getPlainText(element) {
+export function getPlainText (element) {
   return unescapeHTML(traverseInnerText(element))
 }
 
@@ -14,7 +14,7 @@ export function getPlainText(element) {
  * @param {Element} element  An HTML DOM element like a DIV
  * @param {string} text
  */
-export function setPlainText(element, text) {
+export function setPlainText (element, text) {
   element.innerHTML = escapeHTML(text)
 }
 /**
@@ -26,8 +26,7 @@ export function setPlainText(element, text) {
 export function escapeHTML (text, escapeUnicode = false) {
   if (typeof text !== 'string') {
     return String(text)
-  }
-  else {
+  } else {
     let htmlEscaped = String(text)
     if (escapeUnicode === true) {
       // FIXME: should not unescape the just created non-breaking spaces \u00A0 ?
@@ -36,8 +35,8 @@ export function escapeHTML (text, escapeUnicode = false) {
 
     htmlEscaped = htmlEscaped
       .replace(/ {2}/g, ' \u00A0') // replace double space with an nbsp and space
-      .replace(/^ /, '\u00A0')   // space at start
-      .replace(/ $/, '\u00A0')   // space at end
+      .replace(/^ /, '\u00A0') // space at start
+      .replace(/ $/, '\u00A0') // space at end
 
     const json = JSON.stringify(htmlEscaped)
     return json.substring(1, json.length - 1) // remove enclosing double quotes
@@ -54,8 +53,8 @@ export function escapeUnicodeChars (text) {
   // see https://www.wikiwand.com/en/UTF-16
   // note: we leave surrogate pairs as two individual chars,
   // as JSON doesn't interpret them as a single unicode char.
-  return text.replace(/[\u007F-\uFFFF]/g, function(c) {
-    return '\\u'+('0000' + c.charCodeAt(0).toString(16)).slice(-4)
+  return text.replace(/[\u007F-\uFFFF]/g, function (c) {
+    return '\\u' + ('0000' + c.charCodeAt(0).toString(16)).slice(-4)
   })
 }
 
@@ -68,7 +67,7 @@ export function unescapeHTML (escapedText) {
   const json = '"' + escapeJSON(escapedText) + '"'
   const htmlEscaped = JSON.parse(json) // TODO: replace with a JSON.parse which does do linting and give an informative error
 
-  return htmlEscaped.replace(/\u00A0/g, ' ')  // nbsp character
+  return htmlEscaped.replace(/\u00A0/g, ' ') // nbsp character
 }
 
 /**
@@ -88,21 +87,18 @@ export function escapeJSON (text) {
     let c = text.charAt(i)
     if (c === '\n') {
       escaped += '\\n'
-    }
-    else if (c === '\\') {
+    } else if (c === '\\') {
       escaped += c
       i++
 
       c = text.charAt(i)
       if (c === '' || '"\\/bfnrtu'.indexOf(c) === -1) {
-        escaped += '\\'  // no valid escape character
+        escaped += '\\' // no valid escape character
       }
       escaped += c
-    }
-    else if (c === '"') {
+    } else if (c === '"') {
       escaped += '\\"'
-    }
-    else {
+    } else {
       escaped += c
     }
     i++
@@ -192,7 +188,7 @@ export function isContentEditableDiv (element) {
   return (element.nodeName === 'DIV' && element.contentEditable === 'true')
 }
 
-function hasAttribute(element, name, value) {
+function hasAttribute (element, name, value) {
   return typeof element.getAttribute === 'function' && element.getAttribute(name) === value
 }
 
diff --git a/src/utils/domUtils.test.js b/src/utils/domUtils.test.js
index 8f54255..f829320 100644
--- a/src/utils/domUtils.test.js
+++ b/src/utils/domUtils.test.js
@@ -18,4 +18,4 @@ describe('domUtils', () => {
 
     // TODO: test unescapeHTML more thoroughly
   })
-})
\ No newline at end of file
+})
diff --git a/src/utils/immutabilityHelpers.js b/src/utils/immutabilityHelpers.js
index d8839b7..53a827c 100644
--- a/src/utils/immutabilityHelpers.js
+++ b/src/utils/immutabilityHelpers.js
@@ -1,4 +1,4 @@
-import { isObjectOrArray } from  './typeUtils.js'
+import { isObjectOrArray } from './typeUtils.js'
 
 /**
  * Immutability helpers
@@ -23,20 +23,22 @@ export function shallowClone (value) {
     const copy = value.slice()
 
     // copy all symbols
-    Object.getOwnPropertySymbols(value).forEach(symbol => copy[symbol] = value[symbol])
+    Object.getOwnPropertySymbols(value).forEach(symbol => {
+      copy[symbol] = value[symbol]
+    })
 
     return copy
-  }
-  else if (typeof value === 'object') {
+  } else if (typeof value === 'object') {
     // copy object properties
     const copy = { ...value }
 
     // copy all symbols
-    Object.getOwnPropertySymbols(value).forEach(symbol => copy[symbol] = value[symbol])
+    Object.getOwnPropertySymbols(value).forEach(symbol => {
+      copy[symbol] = value[symbol]
+    })
 
     return copy
-  }
-  else {
+  } else {
     return value
   }
 }
@@ -53,8 +55,7 @@ export function applyProp (object, key, value) {
   if (object[key] === value) {
     // return original object unchanged when the new value is identical to the old one
     return object
-  }
-  else {
+  } else {
     const updatedObject = shallowClone(object)
     updatedObject[key] = value
     return updatedObject
@@ -73,11 +74,10 @@ export function getIn (object, path) {
   let value = object
   let i = 0
 
-  while(i < path.length) {
+  while (i < path.length) {
     if (isObjectOrArray(value)) {
       value = value[path[i]]
-    }
-    else {
+    } else {
       value = undefined
     }
 
@@ -171,14 +171,12 @@ export function deleteIn (object, path) {
     if (!(key in object)) {
       // key doesn't exist. return object unchanged
       return object
-    }
-    else {
+    } else {
       const updatedObject = shallowClone(object)
 
       if (Array.isArray(updatedObject)) {
         updatedObject.splice(key, 1)
-      }
-      else {
+      } else {
         delete updatedObject[key]
       }
 
@@ -230,7 +228,7 @@ export function transform (json, callback, path = []) {
   const updated1 = callback(json, path)
 
   if (Array.isArray(json)) { // array
-    let updated2 = undefined
+    let updated2
 
     for (let i = 0; i < updated1.length; i++) {
       const before = updated1[i]
@@ -246,13 +244,12 @@ export function transform (json, callback, path = []) {
       }
     }
 
-    return updated2 ? updated2 : updated1
-  }
-  else if (json && typeof json === 'object') { // object
-    let updated2 = undefined
+    return updated2 || updated1
+  } else if (json && typeof json === 'object') { // object
+    let updated2
 
-    for (let key in updated1) {
-      if (updated1.hasOwnProperty(key)) {
+    for (const key in updated1) {
+      if (Object.hasOwnProperty.call(updated1, key)) {
         const before = updated1[key]
         const after = transform(before, callback, path.concat(key))
         if (after !== before) {
@@ -264,9 +261,8 @@ export function transform (json, callback, path = []) {
       }
     }
 
-    return updated2 ? updated2 : updated1
-  }
-  else { // number, string, boolean, null
+    return updated2 || updated1
+  } else { // number, string, boolean, null
     return updated1
   }
 }
diff --git a/src/utils/immutabilityHelpers.test.js b/src/utils/immutabilityHelpers.test.js
index cca5ad4..3f8fa16 100644
--- a/src/utils/immutabilityHelpers.test.js
+++ b/src/utils/immutabilityHelpers.test.js
@@ -27,7 +27,7 @@ describe('immutabilityHelpers', () => {
       ]
     }
 
-    assert.deepStrictEqual(getIn(obj, ['a', 'b']), {c: 2})
+    assert.deepStrictEqual(getIn(obj, ['a', 'b']), { c: 2 })
     assert.deepStrictEqual(getIn(obj, ['e', '1', 'f']), 5)
     assert.deepStrictEqual(getIn(obj, ['e', '999', 'f']), undefined)
     assert.deepStrictEqual(getIn(obj, ['non', 'existing', 'path']), undefined)
@@ -92,7 +92,7 @@ describe('immutabilityHelpers', () => {
       a: [
         ,
         ,
-        { c : 4 }
+        { c: 4 }
       ]
     })
     assert.deepStrictEqual(obj, {})
@@ -104,7 +104,7 @@ describe('immutabilityHelpers', () => {
       d: 3
     }
 
-    assert.throws(()  => setIn(obj, ['a', 'b', 'c'], 4), /Path does not exist/)
+    assert.throws(() => setIn(obj, ['a', 'b', 'c'], 4), /Path does not exist/)
   })
 
   it('setIn replace value inside nested array', () => {
@@ -136,7 +136,7 @@ describe('immutabilityHelpers', () => {
   })
 
   it('setIn identical value should return the original object', () => {
-    const obj = {a:1, b:2}
+    const obj = { a: 1, b: 2 }
 
     const updated = setIn(obj, ['b'], 2)
 
@@ -144,7 +144,7 @@ describe('immutabilityHelpers', () => {
   })
 
   it('setIn identical value should return the original object (2)', () => {
-    const obj = {a:1, b: { c: 2}}
+    const obj = { a: 1, b: { c: 2 } }
 
     const updated = setIn(obj, ['b', 'c'], 2)
 
@@ -194,10 +194,10 @@ describe('immutabilityHelpers', () => {
       d: 3
     }
 
-    const updated = updateIn(obj, ['a', 'b' ], (obj) => [1,2,3])
+    const updated = updateIn(obj, ['a', 'b'], (obj) => [1, 2, 3])
     assert.deepStrictEqual(updated, {
       a: {
-        b: [1,2,3]
+        b: [1, 2, 3]
       },
       d: 3
     })
@@ -213,7 +213,7 @@ describe('immutabilityHelpers', () => {
       d: 3
     }
 
-    const updated = updateIn(obj, ['a', 'e' ], (value) => 'foo-' + value)
+    const updated = updateIn(obj, ['a', 'e'], (value) => 'foo-' + value)
     assert.deepStrictEqual(updated, {
       a: {
         b: {
@@ -231,7 +231,7 @@ describe('immutabilityHelpers', () => {
       b: 3
     }
 
-    const updated = updateIn(obj, ['b' ], (value) => 3)
+    const updated = updateIn(obj, ['b'], (value) => 3)
     assert.strictEqual(updated, obj)
   })
 
@@ -273,7 +273,7 @@ describe('immutabilityHelpers', () => {
   it('deleteIn array', () => {
     const obj = {
       a: {
-        b: [1, {c: 2, d: 3} , 4]
+        b: [1, { c: 2, d: 3 }, 4]
       },
       e: 5
     }
@@ -281,7 +281,7 @@ describe('immutabilityHelpers', () => {
     const updated = deleteIn(obj, ['a', 'b', '1', 'c'])
     assert.deepStrictEqual(updated, {
       a: {
-        b: [1, {d: 3} , 4]
+        b: [1, { d: 3 }, 4]
       },
       e: 5
     })
@@ -289,7 +289,7 @@ describe('immutabilityHelpers', () => {
     // original should be unchanged
     assert.deepStrictEqual(obj, {
       a: {
-        b: [1, {c: 2, d: 3} , 4]
+        b: [1, { c: 2, d: 3 }, 4]
       },
       e: 5
     })
@@ -298,54 +298,54 @@ describe('immutabilityHelpers', () => {
   })
 
   it('deleteIn non existing path', () => {
-    const obj = { a: {}}
+    const obj = { a: {} }
 
     const updated = deleteIn(obj, ['a', 'b'])
     assert.strictEqual(updated, obj)
   })
 
   it('insertAt', () => {
-    const obj = { a: [1,2,3]}
+    const obj = { a: [1, 2, 3] }
 
     const updated = insertAt(obj, ['a', '2'], 8)
-    assert.deepStrictEqual(updated, {a: [1,2,8,3]})
+    assert.deepStrictEqual(updated, { a: [1, 2, 8, 3] })
   })
 
   it('insertAt should copy symbols', () => {
     const symbol = Symbol('test symbol')
-    const obj = { a: [1,2,3] }
+    const obj = { a: [1, 2, 3] }
     obj.a[symbol] = 'test'
 
     const updated = insertAt(obj, ['a', '2'], 8)
 
-    const expected = {a: [1,2,8,3]}
+    const expected = { a: [1, 2, 8, 3] }
     expected.a[symbol] = 'test'
     assert.deepStrictEqual(updated, expected)
   })
 
   it('transform (no change)', () => {
-    const json = {a: [1,2,3], b: {c: 4}}
+    const json = { a: [1, 2, 3], b: { c: 4 } }
     const updated = transform(json, (value, path) => value)
     assert.strictEqual(updated, json)
   })
 
   it('transform (change based on value)', () => {
-    const json = {a: [1,2,3], b: {c: 4}}
+    const json = { a: [1, 2, 3], b: { c: 4 } }
 
     const updated = transform(json,
       (value, path) => value === 2 ? 20 : value)
-    const expected = {a: [1,20,3], b: {c: 4}}
+    const expected = { a: [1, 20, 3], b: { c: 4 } }
 
     assert.deepStrictEqual(updated, expected)
     assert.strictEqual(updated.b, json.b) // should not have replaced b
   })
 
   it('transform (change based on path)', () => {
-    const json = {a: [1,2,3], b: {c: 4}}
+    const json = { a: [1, 2, 3], b: { c: 4 } }
 
     const updated = transform(json,
       (value, path) => path.join('.') === 'a.1' ? 20 : value)
-    const expected = {a: [1,20,3], b: {c: 4}}
+    const expected = { a: [1, 20, 3], b: { c: 4 } }
 
     assert.deepStrictEqual(updated, expected)
     assert.strictEqual(updated.b, json.b) // should not have replaced b
@@ -353,12 +353,12 @@ describe('immutabilityHelpers', () => {
 
   it('existsIn', () => {
     const json = {
-      "obj": {
-        "arr": [1,2, {"first":3,"last":4}]
+      obj: {
+        arr: [1, 2, { first: 3, last: 4 }]
       },
-      "str": "hello world",
-      "nill": null,
-      "bool": false
+      str: 'hello world',
+      nill: null,
+      bool: false
     }
 
     assert.deepStrictEqual(existsIn(json, ['obj', 'arr', 2, 'first']), true)
@@ -366,17 +366,8 @@ describe('immutabilityHelpers', () => {
     assert.deepStrictEqual(existsIn(json, ['obj', 'foo', 'bar']), false)
     assert.deepStrictEqual(existsIn(json, []), true)
   })
-  
-  it('existsIn should find symbols', () => {
-    const json = {
-      "obj": {
-        "arr": [1,2, {"first":3,"last":4}]
-      },
-      "str": "hello world",
-      "nill": null,
-      "bool": false
-    }
 
+  it('existsIn should find symbols', () => {
     const symbol = Symbol('mySymbol')
 
     const arrWithSymbol = [1, 2, 3]
@@ -387,4 +378,4 @@ describe('immutabilityHelpers', () => {
     assert.deepStrictEqual(existsIn({ a: 1, [symbol]: 2 }, [symbol]), true)
     assert.deepStrictEqual(existsIn({ a: 1 }, [symbol]), false)
   })
-})
\ No newline at end of file
+})
diff --git a/src/utils/immutableJSONPatch.js b/src/utils/immutableJSONPatch.js
index ab9d359..dc54501 100644
--- a/src/utils/immutableJSONPatch.js
+++ b/src/utils/immutableJSONPatch.js
@@ -22,8 +22,8 @@ export function immutableJSONPatch (json, operations) {
 
   for (let i = 0; i < operations.length; i++) {
     const operation = operations[i]
-    const path = operation.path != undefined ? parseJSONPointer(operation.path) : null
-    const from = operation.from != undefined ? parseJSONPointer(operation.from) : null
+    const path = operation.path !== undefined ? parseJSONPointer(operation.path) : null
+    const from = operation.from !== undefined ? parseJSONPointer(operation.from) : null
 
     switch (operation.op) {
       case 'add': {
@@ -85,7 +85,7 @@ export function immutableJSONPatch (json, operations) {
         // when a test fails, cancel the whole patch and return the error
         const error = test(updatedJson, path, operation.value)
         if (error) {
-          return { json, revert: [], error}
+          return { json, revert: [], error }
         }
 
         break
@@ -160,12 +160,12 @@ export function add (json, path, value) {
   const parent = getIn(json, initial(path))
   const parentIsArray = Array.isArray(parent)
   const oldValue = parentIsArray
-      ? undefined
-      : getIn(json, resolvedPath)
+    ? undefined
+    : getIn(json, resolvedPath)
 
   const updatedJson = parentIsArray
-      ? insertAt(json, resolvedPath, value)
-      : setIn(json, resolvedPath, value)
+    ? insertAt(json, resolvedPath, value)
+    : setIn(json, resolvedPath, value)
 
   if (!parentIsArray && existsIn(json, resolvedPath)) {
     return {
@@ -176,8 +176,7 @@ export function add (json, path, value) {
         value: oldValue
       }]
     }
-  }
-  else {
+  } else {
     return {
       json: updatedJson,
       revert: [{
@@ -219,8 +218,8 @@ export function move (json, path, from) {
 
   const removedJson = remove(json, from).json
   const updatedJson = parentIsArray
-      ? insertAt(removedJson, resolvedPath, value)
-      : setIn(removedJson, resolvedPath, value)
+    ? insertAt(removedJson, resolvedPath, value)
+    : setIn(removedJson, resolvedPath, value)
 
   if (oldValue !== undefined && !parentIsArray) {
     // replaces an existing value in an object
@@ -239,8 +238,7 @@ export function move (json, path, from) {
         }
       ]
     }
-  }
-  else {
+  } else {
     return {
       json: updatedJson,
       revert: [
@@ -287,6 +285,6 @@ export function resolvePathIndex (json, path) {
   const parent = getIn(json, initial(path))
 
   return (path[path.length - 1] === '-')
-      ? path.slice(0, path.length - 1).concat(parent.length)
-      : path
+    ? path.slice(0, path.length - 1).concat(parent.length)
+    : path
 }
diff --git a/src/utils/immutableJSONPatch.test.js b/src/utils/immutableJSONPatch.test.js
index 548314a..3da8205 100644
--- a/src/utils/immutableJSONPatch.test.js
+++ b/src/utils/immutableJSONPatch.test.js
@@ -14,92 +14,92 @@ describe('immutableJSONPatch', () => {
 
   it('jsonpatch add', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 2}
+      arr: [1, 2, 3],
+      obj: { a: 2 }
     }
 
     const patch = [
-      {op: 'add', path: '/obj/b', value: {foo: 'bar'}}
+      { op: 'add', path: '/obj/b', value: { foo: 'bar' } }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1,2,3],
-      obj: {a : 2, b: {foo: 'bar'}}
+      arr: [1, 2, 3],
+      obj: { a: 2, b: { foo: 'bar' } }
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'remove', path: '/obj/b'}
+      { op: 'remove', path: '/obj/b' }
     ])
     assert.strictEqual(result.json.arr, json.arr)
   })
 
   it('jsonpatch add: insert in matrix', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 2}
+      arr: [1, 2, 3],
+      obj: { a: 2 }
     }
 
     const patch = [
-      {op: 'add', path: '/arr/1', value: 4}
+      { op: 'add', path: '/arr/1', value: 4 }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1,4,2,3],
-      obj: {a : 2}
+      arr: [1, 4, 2, 3],
+      obj: { a: 2 }
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'remove', path: '/arr/1'}
+      { op: 'remove', path: '/arr/1' }
     ])
     assert.strictEqual(result.json.obj, json.obj)
   })
 
   it('jsonpatch add: append to matrix', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 2}
+      arr: [1, 2, 3],
+      obj: { a: 2 }
     }
 
     const patch = [
-      {op: 'add', path: '/arr/-', value: 4}
+      { op: 'add', path: '/arr/-', value: 4 }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1,2,3,4],
-      obj: {a : 2}
+      arr: [1, 2, 3, 4],
+      obj: { a: 2 }
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'remove', path: '/arr/3'}
+      { op: 'remove', path: '/arr/3' }
     ])
     assert.strictEqual(result.json.obj, json.obj)
   })
 
   it('jsonpatch remove', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4},
+      arr: [1, 2, 3],
+      obj: { a: 4 },
       unchanged: {}
     }
 
     const patch = [
-      {op: 'remove', path: '/obj/a'},
-      {op: 'remove', path: '/arr/1'},
+      { op: 'remove', path: '/obj/a' },
+      { op: 'remove', path: '/arr/1' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1,3],
+      arr: [1, 3],
       obj: {},
       unchanged: {}
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'add', path: '/arr/1', value: 2},
-      {op: 'add', path: '/obj/a', value: 4}
+      { op: 'add', path: '/arr/1', value: 2 },
+      { op: 'add', path: '/obj/a', value: 4 }
     ])
 
     // test revert
@@ -112,26 +112,26 @@ describe('immutableJSONPatch', () => {
 
   it('jsonpatch replace', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4},
+      arr: [1, 2, 3],
+      obj: { a: 4 },
       unchanged: {}
     }
 
     const patch = [
-      {op: 'replace', path: '/obj/a', value: 400},
-      {op: 'replace', path: '/arr/1', value: 200},
+      { op: 'replace', path: '/obj/a', value: 400 },
+      { op: 'replace', path: '/arr/1', value: 200 }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1,200,3],
-      obj: {a: 400},
+      arr: [1, 200, 3],
+      obj: { a: 400 },
       unchanged: {}
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'replace', path: '/arr/1', value: 2},
-      {op: 'replace', path: '/obj/a', value: 4}
+      { op: 'replace', path: '/arr/1', value: 2 },
+      { op: 'replace', path: '/obj/a', value: 4 }
     ])
 
     // test revert
@@ -139,8 +139,8 @@ describe('immutableJSONPatch', () => {
 
     assert.deepStrictEqual(result2.json, json)
     assert.deepStrictEqual(result2.revert, [
-      {op: 'replace', path: '/obj/a', value: 400},
-      {op: 'replace', path: '/arr/1', value: 200}
+      { op: 'replace', path: '/obj/a', value: 400 },
+      { op: 'replace', path: '/arr/1', value: 200 }
     ])
     assert.strictEqual(result.json.unchanged, json.unchanged)
   })
@@ -150,31 +150,31 @@ describe('immutableJSONPatch', () => {
       a: 2
     }
     const patch = [
-      {op: 'replace', path: '', value: {b: 3}}
+      { op: 'replace', path: '', value: { b: 3 } }
     ]
     const result = immutableJSONPatch(json, patch)
-    
-    assert.deepStrictEqual(result.json, {b: 3})
+
+    assert.deepStrictEqual(result.json, { b: 3 })
   })
 
   it('jsonpatch copy', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4}
+      arr: [1, 2, 3],
+      obj: { a: 4 }
     }
 
     const patch = [
-      {op: 'copy', from: '/obj', path: '/arr/2'},
+      { op: 'copy', from: '/obj', path: '/arr/2' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1, 2, {a:4}, 3],
-      obj: {a: 4}
+      arr: [1, 2, { a: 4 }, 3],
+      obj: { a: 4 }
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'remove', path: '/arr/2'}
+      { op: 'remove', path: '/arr/2' }
     ])
 
     // test revert
@@ -182,7 +182,7 @@ describe('immutableJSONPatch', () => {
 
     assert.deepStrictEqual(result2.json, json)
     assert.deepStrictEqual(result2.revert, [
-      {op: 'add', path: '/arr/2', value: {a: 4}}
+      { op: 'add', path: '/arr/2', value: { a: 4 } }
     ])
     assert.strictEqual(result.json.obj, json.obj)
     assert.strictEqual(result.json.arr[2], json.obj)
@@ -190,24 +190,24 @@ describe('immutableJSONPatch', () => {
 
   it('jsonpatch move', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4},
+      arr: [1, 2, 3],
+      obj: { a: 4 },
       unchanged: {}
     }
 
     const patch = [
-      {op: 'move', from: '/obj', path: '/arr/2'},
+      { op: 'move', from: '/obj', path: '/arr/2' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.error, null)
     assert.deepStrictEqual(result.json, {
-      arr: [1, 2, {a:4}, 3],
+      arr: [1, 2, { a: 4 }, 3],
       unchanged: {}
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'move', from: '/arr/2', path: '/obj'}
+      { op: 'move', from: '/arr/2', path: '/obj' }
     ])
 
     // test revert
@@ -223,15 +223,15 @@ describe('immutableJSONPatch', () => {
     const json = { a: 2, b: 3 }
 
     const patch = [
-      {op: 'move', from: '/a', path: '/b'},
+      { op: 'move', from: '/a', path: '/b' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
-    assert.deepStrictEqual(result.json, { b : 2 })
+    assert.deepStrictEqual(result.json, { b: 2 })
     assert.deepStrictEqual(result.revert, [
-      {op:'move', from: '/b', path: '/a'},
-      {op:'add', path:'/b', value: 3}
+      { op: 'move', from: '/b', path: '/a' },
+      { op: 'add', path: '/b', value: 3 }
     ])
 
     // test revert
@@ -239,31 +239,31 @@ describe('immutableJSONPatch', () => {
 
     assert.deepStrictEqual(result2.json, json)
     assert.deepStrictEqual(result2.revert, [
-      {op: 'remove', path: '/b'},
-      {op: 'move', from: '/a', path: '/b'}
+      { op: 'remove', path: '/b' },
+      { op: 'move', from: '/a', path: '/b' }
     ])
   })
 
   it('jsonpatch move and replace (nested)', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4},
+      arr: [1, 2, 3],
+      obj: { a: 4 },
       unchanged: {}
     }
 
     const patch = [
-      {op: 'move', from: '/obj', path: '/arr'},
+      { op: 'move', from: '/obj', path: '/arr' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: {a:4},
+      arr: { a: 4 },
       unchanged: {}
     })
     assert.deepStrictEqual(result.revert, [
-      {op:'move', from: '/arr', path: '/obj'},
-      {op:'add', path:'/arr', value: [1,2,3]}
+      { op: 'move', from: '/arr', path: '/obj' },
+      { op: 'add', path: '/arr', value: [1, 2, 3] }
     ])
 
     // test revert
@@ -271,8 +271,8 @@ describe('immutableJSONPatch', () => {
 
     assert.deepStrictEqual(result2.json, json)
     assert.deepStrictEqual(result2.revert, [
-      {op: 'remove', path: '/arr'},
-      {op: 'move', from: '/obj', path: '/arr'}
+      { op: 'remove', path: '/arr' },
+      { op: 'move', from: '/obj', path: '/arr' }
     ])
     assert.strictEqual(result.json.unchanged, json.unchanged)
     assert.strictEqual(result2.json.unchanged, json.unchanged)
@@ -280,44 +280,44 @@ describe('immutableJSONPatch', () => {
 
   it('jsonpatch test (ok)', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4}
+      arr: [1, 2, 3],
+      obj: { a: 4 }
     }
 
     const patch = [
-      {op: 'test', path: '/arr', value: [1,2,3]},
-      {op: 'add', path: '/added', value: 'ok'}
+      { op: 'test', path: '/arr', value: [1, 2, 3] },
+      { op: 'add', path: '/added', value: 'ok' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     assert.deepStrictEqual(result.json, {
-      arr: [1,2,3],
-      obj: {a : 4},
+      arr: [1, 2, 3],
+      obj: { a: 4 },
       added: 'ok'
     })
     assert.deepStrictEqual(result.revert, [
-      {op: 'remove', path: '/added'}
+      { op: 'remove', path: '/added' }
     ])
   })
 
   it('jsonpatch test (fail: path not found)', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4}
+      arr: [1, 2, 3],
+      obj: { a: 4 }
     }
 
     const patch = [
-      {op: 'test', path: '/arr/5', value: [1,2,3]},
-      {op: 'add', path: '/added', value: 'ok'}
+      { op: 'test', path: '/arr/5', value: [1, 2, 3] },
+      { op: 'add', path: '/added', value: 'ok' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     // patch shouldn't be applied
     assert.deepStrictEqual(result.json, {
-      arr: [1,2,3],
-      obj: {a : 4}
+      arr: [1, 2, 3],
+      obj: { a: 4 }
     })
     assert.deepStrictEqual(result.revert, [])
     assert.deepStrictEqual(result.error.toString(), 'Error: Test failed, path not found')
@@ -325,23 +325,23 @@ describe('immutableJSONPatch', () => {
 
   it('jsonpatch test (fail: value not equal)', () => {
     const json = {
-      arr: [1,2,3],
-      obj: {a : 4}
+      arr: [1, 2, 3],
+      obj: { a: 4 }
     }
 
     const patch = [
-      {op: 'test', path: '/obj', value: {a:4, b: 6}},
-      {op: 'add', path: '/added', value: 'ok'}
+      { op: 'test', path: '/obj', value: { a: 4, b: 6 } },
+      { op: 'add', path: '/added', value: 'ok' }
     ]
 
     const result = immutableJSONPatch(json, patch)
 
     // patch shouldn't be applied
     assert.deepStrictEqual(result.json, {
-      arr: [1,2,3],
-      obj: {a : 4}
+      arr: [1, 2, 3],
+      obj: { a: 4 }
     })
     assert.deepStrictEqual(result.revert, [])
     assert.deepStrictEqual(result.error.toString(), 'Error: Test failed, value differs')
   })
-})
\ No newline at end of file
+})
diff --git a/src/utils/jsonPointer.js b/src/utils/jsonPointer.js
index 7d701ba..5951228 100644
--- a/src/utils/jsonPointer.js
+++ b/src/utils/jsonPointer.js
@@ -19,6 +19,6 @@ export function parseJSONPointer (pointer) {
  */
 export function compileJSONPointer (path) {
   return path
-      .map(p => '/' + String(p).replace(/~/g, '~0').replace(/\//g, '~1'))
-      .join('')
+    .map(p => '/' + String(p).replace(/~/g, '~0').replace(/\//g, '~1'))
+    .join('')
 }
diff --git a/src/utils/jsonPointer.test.js b/src/utils/jsonPointer.test.js
index e92c9d5..fb7280f 100644
--- a/src/utils/jsonPointer.test.js
+++ b/src/utils/jsonPointer.test.js
@@ -1,5 +1,5 @@
 import assert from 'assert'
-import {compileJSONPointer, parseJSONPointer} from './jsonPointer.js'
+import { compileJSONPointer, parseJSONPointer } from './jsonPointer.js'
 
 describe('jsonPointer', () => {
   it('parseJSONPointer', () => {
diff --git a/src/utils/keyBindings.js b/src/utils/keyBindings.js
index 1fffc67..6bd6b9d 100644
--- a/src/utils/keyBindings.js
+++ b/src/utils/keyBindings.js
@@ -12,7 +12,7 @@
  * @param {string} code
  * @return {string}
  */
-export function nameFromKeyCode(code) {
+export function nameFromKeyCode (code) {
   return codes[code] || ''
 }
 
@@ -23,7 +23,7 @@ export function nameFromKeyCode(code) {
  * @return {string}
  */
 export function keyComboFromEvent (event) {
-  let combi = []
+  const combi = []
 
   if (event.ctrlKey) { combi.push('Ctrl') }
   if (event.metaKey) { combi.push('Command') }
@@ -31,7 +31,7 @@ export function keyComboFromEvent (event) {
   if (event.shiftKey) { combi.push('Shift') }
 
   const keyName = nameFromKeyCode(event.which)
-  if (!metaCodes[keyName]) {  // prevent output like 'Ctrl+Ctrl'
+  if (!metaCodes[keyName]) { // prevent output like 'Ctrl+Ctrl'
     combi.push(keyName)
   }
 
@@ -47,8 +47,10 @@ export function keyComboFromEvent (event) {
 export function createFindKeyBinding (keyBindings) {
   // turn the map with key bindings by name (multiple per binding) into a map by key combo
   const keyCombos = {}
-  Object.keys(keyBindings).forEach ((name) => {
-    keyBindings[name].forEach(combo => keyCombos[normalizeKeyCombo(combo)] = name)
+  Object.keys(keyBindings).forEach((name) => {
+    keyBindings[name].forEach(combo => {
+      keyCombos[normalizeKeyCombo(combo)] = name
+    })
   })
 
   return function findKeyBinding (event) {
@@ -81,112 +83,112 @@ function normalizeKeyCombo (combo) {
 const isMac = window.navigator.platform.toUpperCase().indexOf('MAC') >= 0
 
 const metaCodes = {
-  'Ctrl': true,
-  'Command': true,
-  'Alt': true,
-  'Option': true,
-  'Shift': true
+  Ctrl: true,
+  Command: true,
+  Alt: true,
+  Option: true,
+  Shift: true
 }
 
 const codes = {
-  '8': 'Backspace',
-  '9': 'Tab',
-  '13': 'Enter',
-  '16': 'Shift',
-  '17': 'Ctrl',
-  '18': 'Alt',
-  '19': 'Pause_Break',
-  '20': 'Caps_Lock',
-  '27': 'Escape',
-  '33': 'Page_Up',
-  '34': 'Page_Down',
-  '35': 'End',
-  '36': 'Home',
-  '37': 'Left',
-  '38': 'Up',
-  '39': 'Right',
-  '40': 'Down',
-  '45': 'Insert',
-  '46': 'Delete',
-  '48': '0',
-  '49': '1',
-  '50': '2',
-  '51': '3',
-  '52': '4',
-  '53': '5',
-  '54': '6',
-  '55': '7',
-  '56': '8',
-  '57': '9',
-  '65': 'A',
-  '66': 'B',
-  '67': 'C',
-  '68': 'D',
-  '69': 'E',
-  '70': 'F',
-  '71': 'G',
-  '72': 'H',
-  '73': 'I',
-  '74': 'J',
-  '75': 'K',
-  '76': 'L',
-  '77': 'M',
-  '78': 'N',
-  '79': 'O',
-  '80': 'P',
-  '81': 'Q',
-  '82': 'R',
-  '83': 'S',
-  '84': 'T',
-  '85': 'U',
-  '86': 'V',
-  '87': 'W',
-  '88': 'X',
-  '89': 'Y',
-  '90': 'Z',
-  '91': 'Left_Window_Key',
-  '92': 'Right_Window_Key',
-  '93': 'Select_Key',
-  '96': 'Numpad_0',
-  '97': 'Numpad_1',
-  '98': 'Numpad_2',
-  '99': 'Numpad_3',
-  '100': 'Numpad_4',
-  '101': 'Numpad_5',
-  '102': 'Numpad_6',
-  '103': 'Numpad_7',
-  '104': 'Numpad_8',
-  '105': 'Numpad_9',
-  '106': 'Numpad_*',
-  '107': 'Numpad_+',
-  '109': 'Numpad_-',
-  '110': 'Numpad_.',
-  '111': 'Numpad_/',
-  '112': 'F1',
-  '113': 'F2',
-  '114': 'F3',
-  '115': 'F4',
-  '116': 'F5',
-  '117': 'F6',
-  '118': 'F7',
-  '119': 'F8',
-  '120': 'F9',
-  '121': 'F10',
-  '122': 'F11',
-  '123': 'F12',
-  '144': 'Num_Lock',
-  '145': 'Scroll_Lock',
-  '186': ';',
-  '187': '=',
-  '188': ',',
-  '189': '-',
-  '190': '.',
-  '191': '/',
-  '192': '`',
-  '219': '[',
-  '220': '\\',
-  '221': ']',
-  '222': '\''
+  8: 'Backspace',
+  9: 'Tab',
+  13: 'Enter',
+  16: 'Shift',
+  17: 'Ctrl',
+  18: 'Alt',
+  19: 'Pause_Break',
+  20: 'Caps_Lock',
+  27: 'Escape',
+  33: 'Page_Up',
+  34: 'Page_Down',
+  35: 'End',
+  36: 'Home',
+  37: 'Left',
+  38: 'Up',
+  39: 'Right',
+  40: 'Down',
+  45: 'Insert',
+  46: 'Delete',
+  48: '0',
+  49: '1',
+  50: '2',
+  51: '3',
+  52: '4',
+  53: '5',
+  54: '6',
+  55: '7',
+  56: '8',
+  57: '9',
+  65: 'A',
+  66: 'B',
+  67: 'C',
+  68: 'D',
+  69: 'E',
+  70: 'F',
+  71: 'G',
+  72: 'H',
+  73: 'I',
+  74: 'J',
+  75: 'K',
+  76: 'L',
+  77: 'M',
+  78: 'N',
+  79: 'O',
+  80: 'P',
+  81: 'Q',
+  82: 'R',
+  83: 'S',
+  84: 'T',
+  85: 'U',
+  86: 'V',
+  87: 'W',
+  88: 'X',
+  89: 'Y',
+  90: 'Z',
+  91: 'Left_Window_Key',
+  92: 'Right_Window_Key',
+  93: 'Select_Key',
+  96: 'Numpad_0',
+  97: 'Numpad_1',
+  98: 'Numpad_2',
+  99: 'Numpad_3',
+  100: 'Numpad_4',
+  101: 'Numpad_5',
+  102: 'Numpad_6',
+  103: 'Numpad_7',
+  104: 'Numpad_8',
+  105: 'Numpad_9',
+  106: 'Numpad_*',
+  107: 'Numpad_+',
+  109: 'Numpad_-',
+  110: 'Numpad_.',
+  111: 'Numpad_/',
+  112: 'F1',
+  113: 'F2',
+  114: 'F3',
+  115: 'F4',
+  116: 'F5',
+  117: 'F6',
+  118: 'F7',
+  119: 'F8',
+  120: 'F9',
+  121: 'F10',
+  122: 'F11',
+  123: 'F12',
+  144: 'Num_Lock',
+  145: 'Scroll_Lock',
+  186: ';',
+  187: '=',
+  188: ',',
+  189: '-',
+  190: '.',
+  191: '/',
+  192: '`',
+  219: '[',
+  220: '\\',
+  221: ']',
+  222: '\''
 }
 
 // all secondary characters of the keyboard buttons (used via Shift)
@@ -195,14 +197,14 @@ const aliases = {
   '!': '1',
   '@': '2',
   '#': '3',
-  '$': '4',
+  $: '4',
   '%': '5',
   '^': '6',
   '&': '7',
   '*': '8',
   '(': '9',
   ')': '0',
-  '_': '-',
+  _: '-',
   '+': '=',
   '{': '[',
   '}': ']',
diff --git a/src/utils/pathUtils.js b/src/utils/pathUtils.js
index f4a22dd..51f5ee2 100644
--- a/src/utils/pathUtils.js
+++ b/src/utils/pathUtils.js
@@ -1,19 +1,19 @@
 
 /**
- * Stringify a path like 
- * 
- *     ["data", 2, "nested", "property"] 
- * 
+ * Stringify a path like
+ *
+ *     ["data", 2, "nested", "property"]
+ *
  * into a string:
- *    
+ *
  *     ".data[2].nested.property"
- * 
+ *
  * @param {Path}
  * @return {string}
- */ 
+ */
 export function stringifyPath (path) {
   return path.map(prop => {
-    return typeof prop === 'number' 
+    return typeof prop === 'number'
       ? `[${prop}]`
       : `.${prop}`
   }).join('')
diff --git a/src/utils/pathUtils.test.js b/src/utils/pathUtils.test.js
index dea79fb..4e9d111 100644
--- a/src/utils/pathUtils.test.js
+++ b/src/utils/pathUtils.test.js
@@ -3,8 +3,8 @@ import { stringifyPath } from './pathUtils.js'
 
 describe('pathUtils', () => {
   it('stringifyPath', () => {
-    assert.strictEqual(stringifyPath(["data", 2, "nested", "property"]), '.data[2].nested.property')
+    assert.strictEqual(stringifyPath(['data', 2, 'nested', 'property']), '.data[2].nested.property')
     assert.strictEqual(stringifyPath(['']), '.')
     assert.strictEqual(stringifyPath([]), '')
   })
-})
\ No newline at end of file
+})
diff --git a/src/utils/stringUtils.test.js b/src/utils/stringUtils.test.js
index 7feb91c..85d5e49 100644
--- a/src/utils/stringUtils.test.js
+++ b/src/utils/stringUtils.test.js
@@ -9,13 +9,13 @@ import {
 
 describe('stringUtils', () => {
   it('findUniqueName', () => {
-    assert.deepStrictEqual(findUniqueName('other', {'a': true, 'b': true, 'c': true}), 'other')
-    assert.deepStrictEqual(findUniqueName('b', {'a': true, 'b': true, 'c': true}), 'b (copy)')
-    assert.deepStrictEqual(findUniqueName('b', {'a': true, 'b': true, 'c': true, 'b (copy)': true}), 'b (copy 2)')
-    assert.deepStrictEqual(findUniqueName('b (copy)', {'a': true, 'b': true, 'c': true, 'b (copy)': true}), 'b (copy 2)')
-    assert.deepStrictEqual(findUniqueName('b', {'a': true, 'b': true, 'c': true, 'b (copy)': true, 'b (copy 2)': true}), 'b (copy 3)')
-    assert.deepStrictEqual(findUniqueName('b (copy)', {'a': true, 'b': true, 'c': true, 'b (copy)': true, 'b (copy 2)': true}), 'b (copy 3)')
-    assert.deepStrictEqual(findUniqueName('b (copy 2)', {'a': true, 'b': true, 'c': true, 'b (copy)': true, 'b (copy 2)': true}), 'b (copy 3)')
+    assert.deepStrictEqual(findUniqueName('other', { a: true, b: true, c: true }), 'other')
+    assert.deepStrictEqual(findUniqueName('b', { a: true, b: true, c: true }), 'b (copy)')
+    assert.deepStrictEqual(findUniqueName('b', { a: true, b: true, c: true, 'b (copy)': true }), 'b (copy 2)')
+    assert.deepStrictEqual(findUniqueName('b (copy)', { a: true, b: true, c: true, 'b (copy)': true }), 'b (copy 2)')
+    assert.deepStrictEqual(findUniqueName('b', { a: true, b: true, c: true, 'b (copy)': true, 'b (copy 2)': true }), 'b (copy 3)')
+    assert.deepStrictEqual(findUniqueName('b (copy)', { a: true, b: true, c: true, 'b (copy)': true, 'b (copy 2)': true }), 'b (copy 3)')
+    assert.deepStrictEqual(findUniqueName('b (copy 2)', { a: true, b: true, c: true, 'b (copy)': true, 'b (copy 2)': true }), 'b (copy 3)')
   })
 
   it('toCapital', () => {
diff --git a/src/utils/typeUtils.js b/src/utils/typeUtils.js
index e1fabc2..69bd7ba 100644
--- a/src/utils/typeUtils.js
+++ b/src/utils/typeUtils.js
@@ -41,7 +41,7 @@ export function isObjectOrArray (value) {
  * @param {*} value
  * @return {String} type
  */
-export function valueType(value) {
+export function valueType (value) {
   if (value === null) {
     return 'null'
   }
@@ -85,25 +85,20 @@ export function isUrl (text) {
  * @private
  */
 export function stringConvert (str) {
-  const num = Number(str)           // will nicely fail with '123ab'
-  const numFloat = parseFloat(str)  // will nicely fail with '  '
+  const num = Number(str) // will nicely fail with '123ab'
+  const numFloat = parseFloat(str) // will nicely fail with '  '
 
   if (str === '') {
     return ''
-  }
-  else if (str === 'null') {
+  } else if (str === 'null') {
     return null
-  }
-  else if (str === 'true') {
+  } else if (str === 'true') {
     return true
-  }
-  else if (str === 'false') {
+  } else if (str === 'false') {
     return false
-  }
-  else if (!isNaN(num) && !isNaN(numFloat)) {
+  } else if (!isNaN(num) && !isNaN(numFloat)) {
     return num
-  }
-  else {
+  } else {
     return str
   }
 }
diff --git a/src/utils/typeUtils.test.js b/src/utils/typeUtils.test.js
index d601c32..cf068aa 100644
--- a/src/utils/typeUtils.test.js
+++ b/src/utils/typeUtils.test.js
@@ -1 +1 @@
-// TODO: write unit tests
\ No newline at end of file
+// TODO: write unit tests