Convert var to const/let in src files

```
npm install -g jscodeshift
git clone https://github.com/cpojer/js-codemod.git
jscodeshift -t js-codemod/transforms/no-vars.js ./src
```

src/babel.js

@@ -1,13 +1,13 @@
 'use strict';
 
-var crypto = require('crypto');
-var path = require('path');
-var defaultOptions = require('../static/babelrc.json');
+const crypto = require('crypto');
+const path = require('path');
+const defaultOptions = require('../static/babelrc.json');
 
-var babel = null;
-var babelVersionDirectory = null;
+let babel = null;
+let babelVersionDirectory = null;
 
-var PREFIXES = [
+const PREFIXES = [
   '/** @babel */',
   '"use babel"',
   "'use babel'",
@@ -15,7 +15,7 @@ var PREFIXES = [
   '// @flow'
 ];
 
-var PREFIX_LENGTH = Math.max.apply(
+const PREFIX_LENGTH = Math.max.apply(
   Math,
   PREFIXES.map(function(prefix) {
     return prefix.length;
@@ -23,7 +23,7 @@ var PREFIX_LENGTH = Math.max.apply(
 );
 
 exports.shouldCompile = function(sourceCode) {
-  var start = sourceCode.substr(0, PREFIX_LENGTH);
+  const start = sourceCode.substr(0, PREFIX_LENGTH);
   return PREFIXES.some(function(prefix) {
     return start.indexOf(prefix) === 0;
   });
@@ -31,7 +31,7 @@ exports.shouldCompile = function(sourceCode) {
 
 exports.getCachePath = function(sourceCode) {
   if (babelVersionDirectory == null) {
-    var babelVersion = require('babel-core/package.json').version;
+    const babelVersion = require('babel-core/package.json').version;
     babelVersionDirectory = path.join(
       'js',
       'babel',
@@ -51,8 +51,8 @@ exports.getCachePath = function(sourceCode) {
 exports.compile = function(sourceCode, filePath) {
   if (!babel) {
     babel = require('babel-core');
-    var Logger = require('babel-core/lib/transformation/file/logger');
-    var noop = function() {};
+    const Logger = require('babel-core/lib/transformation/file/logger');
+    const noop = function() {};
     Logger.prototype.debug = noop;
     Logger.prototype.verbose = noop;
   }
@@ -61,8 +61,8 @@ exports.compile = function(sourceCode, filePath) {
     filePath = 'file:///' + path.resolve(filePath).replace(/\\/g, '/');
   }
 
-  var options = { filename: filePath };
-  for (var key in defaultOptions) {
+  const options = { filename: filePath };
+  for (const key in defaultOptions) {
     options[key] = defaultOptions[key];
   }
   return babel.transform(sourceCode, options).code;

src/coffee-script.js

@@ -1,8 +1,8 @@
 'use strict';
 
-var crypto = require('crypto');
-var path = require('path');
-var CoffeeScript = null;
+const crypto = require('crypto');
+const path = require('path');
+let CoffeeScript = null;
 
 exports.shouldCompile = function() {
   return true;
@@ -20,7 +20,7 @@ exports.getCachePath = function(sourceCode) {
 
 exports.compile = function(sourceCode, filePath) {
   if (!CoffeeScript) {
-    var previousPrepareStackTrace = Error.prepareStackTrace;
+    const previousPrepareStackTrace = Error.prepareStackTrace;
     CoffeeScript = require('coffee-script');
 
     // When it loads, coffee-script reassigns Error.prepareStackTrace. We have
@@ -33,7 +33,7 @@ exports.compile = function(sourceCode, filePath) {
     filePath = 'file:///' + path.resolve(filePath).replace(/\\/g, '/');
   }
 
-  var output = CoffeeScript.compile(sourceCode, {
+  const output = CoffeeScript.compile(sourceCode, {
     filename: filePath,
     sourceFiles: [filePath],
     inlineMap: true

src/compile-cache.js

@@ -5,16 +5,16 @@
 // Atom's compile-cache when installing or updating packages, using an older
 // version of node.js
 
-var path = require('path');
-var fs = require('fs-plus');
-var sourceMapSupport = require('@atom/source-map-support');
+const path = require('path');
+const fs = require('fs-plus');
+const sourceMapSupport = require('@atom/source-map-support');
 
-var PackageTranspilationRegistry = require('./package-transpilation-registry');
-var CSON = null;
+const PackageTranspilationRegistry = require('./package-transpilation-registry');
+let CSON = null;
 
-var packageTranspilationRegistry = new PackageTranspilationRegistry();
+const packageTranspilationRegistry = new PackageTranspilationRegistry();
 
-var COMPILERS = {
+const COMPILERS = {
   '.js': packageTranspilationRegistry.wrapTranspiler(require('./babel')),
   '.ts': packageTranspilationRegistry.wrapTranspiler(require('./typescript')),
   '.tsx': packageTranspilationRegistry.wrapTranspiler(require('./typescript')),
@@ -43,11 +43,11 @@ exports.removeTranspilerConfigForPath = function(packagePath) {
   packageTranspilationRegistry.removeTranspilerConfigForPath(packagePath);
 };
 
-var cacheStats = {};
-var cacheDirectory = null;
+const cacheStats = {};
+let cacheDirectory = null;
 
 exports.setAtomHomeDirectory = function(atomHome) {
-  var cacheDir = path.join(atomHome, 'compile-cache');
+  let cacheDir = path.join(atomHome, 'compile-cache');
   if (
     process.env.USER === 'root' &&
     process.env.SUDO_USER &&
@@ -68,7 +68,7 @@ exports.getCacheDirectory = function() {
 
 exports.addPathToCache = function(filePath, atomHome) {
   this.setAtomHomeDirectory(atomHome);
-  var extension = path.extname(filePath);
+  const extension = path.extname(filePath);
 
   if (extension === '.cson') {
     if (!CSON) {
@@ -77,7 +77,7 @@ exports.addPathToCache = function(filePath, atomHome) {
     }
     return CSON.readFileSync(filePath);
   } else {
-    var compiler = COMPILERS[extension];
+    const compiler = COMPILERS[extension];
     if (compiler) {
       return compileFileAtPath(compiler, filePath, extension);
     }
@@ -98,10 +98,10 @@ exports.resetCacheStats = function() {
 };
 
 function compileFileAtPath(compiler, filePath, extension) {
-  var sourceCode = fs.readFileSync(filePath, 'utf8');
+  const sourceCode = fs.readFileSync(filePath, 'utf8');
   if (compiler.shouldCompile(sourceCode, filePath)) {
-    var cachePath = compiler.getCachePath(sourceCode, filePath);
-    var compiledCode = readCachedJavaScript(cachePath);
+    const cachePath = compiler.getCachePath(sourceCode, filePath);
+    let compiledCode = readCachedJavaScript(cachePath);
     if (compiledCode != null) {
       cacheStats[extension].hits++;
     } else {
@@ -115,7 +115,7 @@ function compileFileAtPath(compiler, filePath, extension) {
 }
 
 function readCachedJavaScript(relativeCachePath) {
-  var cachePath = path.join(cacheDirectory, relativeCachePath);
+  const cachePath = path.join(cacheDirectory, relativeCachePath);
   if (fs.isFileSync(cachePath)) {
     try {
       return fs.readFileSync(cachePath, 'utf8');
@@ -125,11 +125,11 @@ function readCachedJavaScript(relativeCachePath) {
 }
 
 function writeCachedJavaScript(relativeCachePath, code) {
-  var cachePath = path.join(cacheDirectory, relativeCachePath);
+  const cachePath = path.join(cacheDirectory, relativeCachePath);
   fs.writeFileSync(cachePath, code, 'utf8');
 }
 
-var INLINE_SOURCE_MAP_REGEXP = /\/\/[#@]\s*sourceMappingURL=([^'"\n]+)\s*$/gm;
+const INLINE_SOURCE_MAP_REGEXP = /\/\/[#@]\s*sourceMappingURL=([^'"\n]+)\s*$/gm;
 
 exports.install = function(resourcesPath, nodeRequire) {
   const snapshotSourceMapConsumer = {
@@ -166,7 +166,7 @@ exports.install = function(resourcesPath, nodeRequire) {
         return null;
       }
 
-      var compiler = COMPILERS[path.extname(filePath)];
+      let compiler = COMPILERS[path.extname(filePath)];
       if (!compiler) compiler = COMPILERS['.js'];
 
       try {
@@ -182,7 +182,7 @@ exports.install = function(resourcesPath, nodeRequire) {
         return null;
       }
 
-      var match, lastMatch;
+      let match, lastMatch;
       INLINE_SOURCE_MAP_REGEXP.lastIndex = 0;
       while ((match = INLINE_SOURCE_MAP_REGEXP.exec(fileData))) {
         lastMatch = match;
@@ -191,8 +191,8 @@ exports.install = function(resourcesPath, nodeRequire) {
         return null;
       }
 
-      var sourceMappingURL = lastMatch[1];
-      var rawData = sourceMappingURL.slice(sourceMappingURL.indexOf(',') + 1);
+      const sourceMappingURL = lastMatch[1];
+      const rawData = sourceMappingURL.slice(sourceMappingURL.indexOf(',') + 1);
 
       try {
         var sourceMap = JSON.parse(Buffer.from(rawData, 'base64'));
@@ -208,7 +208,7 @@ exports.install = function(resourcesPath, nodeRequire) {
     }
   });
 
-  var prepareStackTraceWithSourceMapping = Error.prepareStackTrace;
+  const prepareStackTraceWithSourceMapping = Error.prepareStackTrace;
   var prepareStackTrace = prepareStackTraceWithSourceMapping;
 
   function prepareStackTraceWithRawStackAssignment(error, frames) {
@@ -245,13 +245,13 @@ exports.install = function(resourcesPath, nodeRequire) {
   };
 
   Object.keys(COMPILERS).forEach(function(extension) {
-    var compiler = COMPILERS[extension];
+    const compiler = COMPILERS[extension];
 
     Object.defineProperty(nodeRequire.extensions, extension, {
       enumerable: true,
       writable: false,
       value: function(module, filePath) {
-        var code = compileFileAtPath(compiler, filePath, extension);
+        const code = compileFileAtPath(compiler, filePath, extension);
         return module._compile(code, filePath);
       }
     });

src/delegated-listener.js

@@ -1,7 +1,7 @@
 const EventKit = require('event-kit');
 
 module.exports = function listen(element, eventName, selector, handler) {
-  var innerHandler = function(event) {
+  const innerHandler = function(event) {
     if (selector) {
       var currentTarget = event.target;
       while (currentTarget) {

src/history-manager.js

@@ -89,7 +89,7 @@ class HistoryManager {
   }
 
   getProject(paths) {
-    for (var i = 0; i < this.projects.length; i++) {
+    for (let i = 0; i < this.projects.length; i++) {
       if (arrayEquivalent(paths, this.projects[i].paths)) {
         return this.projects[i];
       }
@@ -121,7 +121,7 @@ class HistoryManager {
 
 function arrayEquivalent(a, b) {
   if (a.length !== b.length) return false;
-  for (var i = 0; i < a.length; i++) {
+  for (let i = 0; i < a.length; i++) {
     if (a[i] !== b[i]) return false;
   }
   return true;

src/module-cache.js

@@ -73,7 +73,7 @@ function loadDependencies(modulePath, rootPath, rootMetadata, moduleCache) {
 
     const childMetadata = JSON.parse(fs.readFileSync(childMetadataPath));
     if (childMetadata && childMetadata.version) {
-      var mainPath;
+      let mainPath;
       try {
         mainPath = require.resolve(childPath);
       } catch (error) {

src/package-manager.js

@@ -531,7 +531,7 @@ module.exports = class PackageManager {
     ) => {
       for (const packageName of packageNames) {
         if (!disabledPackageNames.has(packageName)) {
-          var pack = this.getLoadedPackage(packageName);
+          const pack = this.getLoadedPackage(packageName);
           if (pack != null) {
             action(pack);
           }

src/package.js

@@ -1173,7 +1173,7 @@ module.exports = class Package {
       return nativeModulePaths;
     }
 
-    var traversePath = nodeModulesPath => {
+    const traversePath = nodeModulesPath => {
       try {
         for (let modulePath of fs.listSync(nodeModulesPath)) {
           const modulePathNodeFiles = this.getModulePathNodeFiles(modulePath);

src/state-store.js

@@ -43,7 +43,7 @@ module.exports = class StateStore {
       this.dbPromise.then(db => {
         if (db == null) return resolve();
 
-        var request = db
+        const request = db
           .transaction(['states'], 'readwrite')
           .objectStore('states')
           .put({ value: value, storedAt: new Date().toString() }, key);
@@ -59,7 +59,7 @@ module.exports = class StateStore {
       if (!db) return;
 
       return new Promise((resolve, reject) => {
-        var request = db
+        const request = db
           .transaction(['states'])
           .objectStore('states')
           .get(key);
@@ -83,7 +83,7 @@ module.exports = class StateStore {
       this.dbPromise.then(db => {
         if (db == null) return resolve();
 
-        var request = db
+        const request = db
           .transaction(['states'], 'readwrite')
           .objectStore('states')
           .delete(key);
@@ -99,7 +99,7 @@ module.exports = class StateStore {
       if (!db) return;
 
       return new Promise((resolve, reject) => {
-        var request = db
+        const request = db
           .transaction(['states'], 'readwrite')
           .objectStore('states')
           .clear();
@@ -115,7 +115,7 @@ module.exports = class StateStore {
       if (!db) return;
 
       return new Promise((resolve, reject) => {
-        var request = db
+        const request = db
           .transaction(['states'])
           .objectStore('states')
           .count();

src/style-manager.js

@@ -254,7 +254,7 @@ module.exports = class StyleManager {
   }
 
   buildStylesElement() {
-    var stylesElement = new StylesElement();
+    const stylesElement = new StylesElement();
     stylesElement.initialize(this);
     return stylesElement;
   }

src/text-editor-component.js

@@ -306,7 +306,7 @@ module.exports = class TextEditorComponent {
       this.remeasureAllBlockDecorations = false;
 
       const decorations = this.props.model.getDecorations();
-      for (var i = 0; i < decorations.length; i++) {
+      for (let i = 0; i < decorations.length; i++) {
         const decoration = decorations[i];
         const marker = decoration.getMarker();
         if (marker.isValid() && decoration.getProperties().type === 'block') {
@@ -2169,7 +2169,7 @@ module.exports = class TextEditorComponent {
   }
 
   autoscrollOnMouseDrag({ clientX, clientY }, verticalOnly = false) {
-    var {
+    let {
       top,
       bottom,
       left,
@@ -4283,7 +4283,7 @@ class LinesTileComponent {
   }
 
   updateLines(oldProps, newProps) {
-    var {
+    const {
       screenLines,
       tileStartRow,
       lineDecorations,
@@ -4293,20 +4293,20 @@ class LinesTileComponent {
       lineComponentsByScreenLineId
     } = newProps;
 
-    var oldScreenLines = oldProps.screenLines;
-    var newScreenLines = screenLines;
-    var oldScreenLinesEndIndex = oldScreenLines.length;
-    var newScreenLinesEndIndex = newScreenLines.length;
-    var oldScreenLineIndex = 0;
-    var newScreenLineIndex = 0;
-    var lineComponentIndex = 0;
+    const oldScreenLines = oldProps.screenLines;
+    const newScreenLines = screenLines;
+    const oldScreenLinesEndIndex = oldScreenLines.length;
+    const newScreenLinesEndIndex = newScreenLines.length;
+    let oldScreenLineIndex = 0;
+    let newScreenLineIndex = 0;
+    let lineComponentIndex = 0;
 
     while (
       oldScreenLineIndex < oldScreenLinesEndIndex ||
       newScreenLineIndex < newScreenLinesEndIndex
     ) {
-      var oldScreenLine = oldScreenLines[oldScreenLineIndex];
-      var newScreenLine = newScreenLines[newScreenLineIndex];
+      const oldScreenLine = oldScreenLines[oldScreenLineIndex];
+      const newScreenLine = newScreenLines[newScreenLineIndex];
 
       if (oldScreenLineIndex >= oldScreenLinesEndIndex) {
         var newScreenLineComponent = new LineComponent({
@@ -4329,7 +4329,7 @@ class LinesTileComponent {
 
         oldScreenLineIndex++;
       } else if (oldScreenLine === newScreenLine) {
-        var lineComponent = this.lineComponents[lineComponentIndex];
+        const lineComponent = this.lineComponents[lineComponentIndex];
         lineComponent.update({
           screenRow: tileStartRow + newScreenLineIndex,
           lineDecoration: lineDecorations[newScreenLineIndex],
@@ -4340,17 +4340,17 @@ class LinesTileComponent {
         newScreenLineIndex++;
         lineComponentIndex++;
       } else {
-        var oldScreenLineIndexInNewScreenLines = newScreenLines.indexOf(
+        const oldScreenLineIndexInNewScreenLines = newScreenLines.indexOf(
           oldScreenLine
         );
-        var newScreenLineIndexInOldScreenLines = oldScreenLines.indexOf(
+        const newScreenLineIndexInOldScreenLines = oldScreenLines.indexOf(
           newScreenLine
         );
         if (
           newScreenLineIndex < oldScreenLineIndexInNewScreenLines &&
           oldScreenLineIndexInNewScreenLines < newScreenLinesEndIndex
         ) {
-          var newScreenLineComponents = [];
+          const newScreenLineComponents = [];
           while (newScreenLineIndex < oldScreenLineIndexInNewScreenLines) {
             // eslint-disable-next-line no-redeclare
             var newScreenLineComponent = new LineComponent({
@@ -4389,7 +4389,7 @@ class LinesTileComponent {
             oldScreenLineIndex++;
           }
         } else {
-          var oldScreenLineComponent = this.lineComponents[lineComponentIndex];
+          const oldScreenLineComponent = this.lineComponents[lineComponentIndex];
           // eslint-disable-next-line no-redeclare
           var newScreenLineComponent = new LineComponent({
             screenLine: newScreenLines[newScreenLineIndex],
@@ -4416,13 +4416,13 @@ class LinesTileComponent {
   }
 
   getFirstElementForScreenLine(oldProps, screenLine) {
-    var blockDecorations = oldProps.blockDecorations
+    const blockDecorations = oldProps.blockDecorations
       ? oldProps.blockDecorations.get(screenLine.id)
       : null;
     if (blockDecorations) {
-      var blockDecorationElementsBeforeOldScreenLine = [];
+      const blockDecorationElementsBeforeOldScreenLine = [];
       for (let i = 0; i < blockDecorations.length; i++) {
-        var decoration = blockDecorations[i];
+        const decoration = blockDecorations[i];
         if (decoration.position !== 'after') {
           blockDecorationElementsBeforeOldScreenLine.push(
             TextEditor.viewForItem(decoration.item)
@@ -4435,7 +4435,7 @@ class LinesTileComponent {
         i < blockDecorationElementsBeforeOldScreenLine.length;
         i++
       ) {
-        var blockDecorationElement =
+        const blockDecorationElement =
           blockDecorationElementsBeforeOldScreenLine[i];
         if (
           !blockDecorationElementsBeforeOldScreenLine.includes(
@@ -4451,19 +4451,19 @@ class LinesTileComponent {
   }
 
   updateBlockDecorations(oldProps, newProps) {
-    var { blockDecorations, lineComponentsByScreenLineId } = newProps;
+    const { blockDecorations, lineComponentsByScreenLineId } = newProps;
 
     if (oldProps.blockDecorations) {
       oldProps.blockDecorations.forEach((oldDecorations, screenLineId) => {
-        var newDecorations = newProps.blockDecorations
+        const newDecorations = newProps.blockDecorations
           ? newProps.blockDecorations.get(screenLineId)
           : null;
-        for (var i = 0; i < oldDecorations.length; i++) {
-          var oldDecoration = oldDecorations[i];
+        for (let i = 0; i < oldDecorations.length; i++) {
+          const oldDecoration = oldDecorations[i];
           if (newDecorations && newDecorations.includes(oldDecoration))
             continue;
 
-          var element = TextEditor.viewForItem(oldDecoration.item);
+          const element = TextEditor.viewForItem(oldDecoration.item);
           if (element.parentElement !== this.element) continue;
 
           element.remove();
@@ -5125,11 +5125,11 @@ class NodePool {
   }
 
   getElement(type, className, style) {
-    var element;
-    var elementsByDepth = this.elementsByType[type];
+    let element;
+    const elementsByDepth = this.elementsByType[type];
     if (elementsByDepth) {
       while (elementsByDepth.length > 0) {
-        var elements = elementsByDepth[elementsByDepth.length - 1];
+        const elements = elementsByDepth[elementsByDepth.length - 1];
         if (elements && elements.length > 0) {
           element = elements.pop();
           if (elements.length === 0) elementsByDepth.pop();
@@ -5150,7 +5150,7 @@ class NodePool {
       while (element.firstChild) element.firstChild.remove();
       return element;
     } else {
-      var newElement = document.createElement(type);
+      const newElement = document.createElement(type);
       if (className) newElement.className = className;
       if (style) Object.assign(newElement.style, style);
       return newElement;
@@ -5159,7 +5159,7 @@ class NodePool {
 
   getTextNode(text) {
     if (this.textNodes.length > 0) {
-      var node = this.textNodes.pop();
+      const node = this.textNodes.pop();
       node.textContent = text;
       return node;
     } else {
@@ -5168,24 +5168,24 @@ class NodePool {
   }
 
   release(node, depth = 0) {
-    var { nodeName } = node;
+    const { nodeName } = node;
     if (nodeName === '#text') {
       this.textNodes.push(node);
     } else {
-      var elementsByDepth = this.elementsByType[nodeName];
+      let elementsByDepth = this.elementsByType[nodeName];
       if (!elementsByDepth) {
         elementsByDepth = [];
         this.elementsByType[nodeName] = elementsByDepth;
       }
 
-      var elements = elementsByDepth[depth];
+      let elements = elementsByDepth[depth];
       if (!elements) {
         elements = [];
         elementsByDepth[depth] = elements;
       }
 
       elements.push(node);
-      for (var i = 0; i < node.childNodes.length; i++) {
+      for (let i = 0; i < node.childNodes.length; i++) {
         this.release(node.childNodes[i], depth + 1);
       }
     }

src/text-editor-registry.js

@@ -110,7 +110,7 @@ module.exports = class TextEditorRegistry {
   //
   // Returns a {Boolean} indicating whether the editor was successfully removed.
   remove(editor) {
-    var removed = this.editors.delete(editor);
+    const removed = this.editors.delete(editor);
     editor.registered = false;
     return removed;
   }

src/text-mate-language-mode.js

@@ -329,7 +329,7 @@ class TextMateLanguageMode {
     let rowsRemaining = this.chunkSize;
 
     while (this.firstInvalidRow() != null && rowsRemaining > 0) {
-      var endRow, filledRegion;
+      let endRow, filledRegion;
       const startRow = this.invalidRows.shift();
       const lastRow = this.buffer.getLastRow();
       if (startRow > lastRow) continue;

src/tooltip.js

@@ -7,9 +7,9 @@ const listen = require('./delegated-listener');
 // This tooltip class is derived from Bootstrap 3, but modified to not require
 // jQuery, which is an expensive dependency we want to eliminate.
 
-var followThroughTimer = null;
+let followThroughTimer = null;
 
-var Tooltip = function(element, options, viewRegistry) {
+const Tooltip = function(element, options, viewRegistry) {
   this.options = null;
   this.enabled = null;
   this.timeout = null;
@@ -66,9 +66,9 @@ Tooltip.prototype.init = function(element, options) {
     );
   }
 
-  var triggers = this.options.trigger.split(' ');
+  const triggers = this.options.trigger.split(' ');
 
-  for (var i = triggers.length; i--; ) {
+  for (let i = triggers.length; i--; ) {
     var trigger = triggers[i];
 
     if (trigger === 'click') {
@@ -91,7 +91,7 @@ Tooltip.prototype.init = function(element, options) {
     } else if (trigger === 'manual') {
       this.show();
     } else {
-      var eventIn, eventOut;
+      let eventIn, eventOut;
 
       if (trigger === 'hover') {
         this.hideOnKeydownOutsideOfTooltip = () => this.hide();
@@ -175,12 +175,12 @@ Tooltip.prototype.getOptions = function(options) {
 };
 
 Tooltip.prototype.getDelegateOptions = function() {
-  var options = {};
-  var defaults = this.getDefaults();
+  const options = {};
+  const defaults = this.getDefaults();
 
   if (this._options) {
-    for (var key of Object.getOwnPropertyNames(this._options)) {
-      var value = this._options[key];
+    for (const key of Object.getOwnPropertyNames(this._options)) {
+      const value = this._options[key];
       if (defaults[key] !== value) options[key] = value;
     }
   }
@@ -223,7 +223,7 @@ Tooltip.prototype.enter = function(event) {
 };
 
 Tooltip.prototype.isInStateTrue = function() {
-  for (var key in this.inState) {
+  for (const key in this.inState) {
     if (this.inState[key]) return true;
   }
 
@@ -272,9 +272,9 @@ Tooltip.prototype.show = function() {
       );
     }
 
-    var tip = this.getTooltipElement();
+    const tip = this.getTooltipElement();
     this.startObservingMutations();
-    var tipId = this.getUID('tooltip');
+    const tipId = this.getUID('tooltip');
 
     this.setContent();
     tip.setAttribute('id', tipId);
@@ -282,13 +282,13 @@ Tooltip.prototype.show = function() {
 
     if (this.options.animation) tip.classList.add('fade');
 
-    var placement =
+    let placement =
       typeof this.options.placement === 'function'
         ? this.options.placement.call(this, tip, this.element)
         : this.options.placement;
 
-    var autoToken = /\s?auto?\s?/i;
-    var autoPlace = autoToken.test(placement);
+    const autoToken = /\s?auto?\s?/i;
+    const autoPlace = autoToken.test(placement);
     if (autoPlace) placement = placement.replace(autoToken, '') || 'top';
 
     tip.remove();
@@ -299,13 +299,13 @@ Tooltip.prototype.show = function() {
 
     document.body.appendChild(tip);
 
-    var pos = this.element.getBoundingClientRect();
-    var actualWidth = tip.offsetWidth;
-    var actualHeight = tip.offsetHeight;
+    const pos = this.element.getBoundingClientRect();
+    const actualWidth = tip.offsetWidth;
+    const actualHeight = tip.offsetHeight;
 
     if (autoPlace) {
-      var orgPlacement = placement;
-      var viewportDim = this.viewport.getBoundingClientRect();
+      const orgPlacement = placement;
+      const viewportDim = this.viewport.getBoundingClientRect();
 
       placement =
         placement === 'bottom' && pos.bottom + actualHeight > viewportDim.bottom
@@ -322,7 +322,7 @@ Tooltip.prototype.show = function() {
       tip.classList.add(placement);
     }
 
-    var calculatedOffset = this.getCalculatedOffset(
+    const calculatedOffset = this.getCalculatedOffset(
       placement,
       pos,
       actualWidth,
@@ -331,7 +331,7 @@ Tooltip.prototype.show = function() {
 
     this.applyPlacement(calculatedOffset, placement);
 
-    var prevHoverState = this.hoverState;
+    const prevHoverState = this.hoverState;
     this.hoverState = null;
 
     if (prevHoverState === 'out') this.leave();
@@ -339,15 +339,15 @@ Tooltip.prototype.show = function() {
 };
 
 Tooltip.prototype.applyPlacement = function(offset, placement) {
-  var tip = this.getTooltipElement();
+  const tip = this.getTooltipElement();
 
-  var width = tip.offsetWidth;
-  var height = tip.offsetHeight;
+  const width = tip.offsetWidth;
+  const height = tip.offsetHeight;
 
   // manually read margins because getBoundingClientRect includes difference
-  var computedStyle = window.getComputedStyle(tip);
-  var marginTop = parseInt(computedStyle.marginTop, 10);
-  var marginLeft = parseInt(computedStyle.marginLeft, 10);
+  const computedStyle = window.getComputedStyle(tip);
+  const marginTop = parseInt(computedStyle.marginTop, 10);
+  const marginLeft = parseInt(computedStyle.marginLeft, 10);
 
   offset.top += marginTop;
   offset.left += marginLeft;
@@ -358,14 +358,14 @@ Tooltip.prototype.applyPlacement = function(offset, placement) {
   tip.classList.add('in');
 
   // check to see if placing tip in new offset caused the tip to resize itself
-  var actualWidth = tip.offsetWidth;
-  var actualHeight = tip.offsetHeight;
+  const actualWidth = tip.offsetWidth;
+  const actualHeight = tip.offsetHeight;
 
   if (placement === 'top' && actualHeight !== height) {
     offset.top = offset.top + height - actualHeight;
   }
 
-  var delta = this.getViewportAdjustedDelta(
+  const delta = this.getViewportAdjustedDelta(
     placement,
     offset,
     actualWidth,
@@ -375,11 +375,11 @@ Tooltip.prototype.applyPlacement = function(offset, placement) {
   if (delta.left) offset.left += delta.left;
   else offset.top += delta.top;
 
-  var isVertical = /top|bottom/.test(placement);
-  var arrowDelta = isVertical
+  const isVertical = /top|bottom/.test(placement);
+  const arrowDelta = isVertical
     ? delta.left * 2 - width + actualWidth
     : delta.top * 2 - height + actualHeight;
-  var arrowOffsetPosition = isVertical ? 'offsetWidth' : 'offsetHeight';
+  const arrowOffsetPosition = isVertical ? 'offsetWidth' : 'offsetHeight';
 
   tip.style.top = offset.top + 'px';
   tip.style.left = offset.left + 'px';
@@ -388,8 +388,8 @@ Tooltip.prototype.applyPlacement = function(offset, placement) {
 };
 
 Tooltip.prototype.replaceArrow = function(delta, dimension, isVertical) {
-  var arrow = this.getArrowElement();
-  var amount = 50 * (1 - delta / dimension) + '%';
+  const arrow = this.getArrowElement();
+  const amount = 50 * (1 - delta / dimension) + '%';
 
   if (isVertical) {
     arrow.style.left = amount;
@@ -401,17 +401,17 @@ Tooltip.prototype.replaceArrow = function(delta, dimension, isVertical) {
 };
 
 Tooltip.prototype.setContent = function() {
-  var tip = this.getTooltipElement();
+  const tip = this.getTooltipElement();
 
   if (this.options.class) {
     tip.classList.add(this.options.class);
   }
 
-  var inner = tip.querySelector('.tooltip-inner');
+  const inner = tip.querySelector('.tooltip-inner');
   if (this.options.item) {
     inner.appendChild(this.viewRegistry.getView(this.options.item));
   } else {
-    var title = this.getTitle();
+    const title = this.getTitle();
     if (this.options.html) {
       inner.innerHTML = title;
     } else {
@@ -506,16 +506,16 @@ Tooltip.prototype.getViewportAdjustedDelta = function(
   actualWidth,
   actualHeight
 ) {
-  var delta = { top: 0, left: 0 };
+  const delta = { top: 0, left: 0 };
   if (!this.viewport) return delta;
 
-  var viewportPadding =
+  const viewportPadding =
     (this.options.viewport && this.options.viewport.padding) || 0;
-  var viewportDimensions = this.viewport.getBoundingClientRect();
+  const viewportDimensions = this.viewport.getBoundingClientRect();
 
   if (/right|left/.test(placement)) {
-    var topEdgeOffset = pos.top - viewportPadding - viewportDimensions.scroll;
-    var bottomEdgeOffset =
+    const topEdgeOffset = pos.top - viewportPadding - viewportDimensions.scroll;
+    const bottomEdgeOffset =
       pos.top + viewportPadding - viewportDimensions.scroll + actualHeight;
     if (topEdgeOffset < viewportDimensions.top) {
       // top overflow
@@ -529,8 +529,8 @@ Tooltip.prototype.getViewportAdjustedDelta = function(
         viewportDimensions.top + viewportDimensions.height - bottomEdgeOffset;
     }
   } else {
-    var leftEdgeOffset = pos.left - viewportPadding;
-    var rightEdgeOffset = pos.left + viewportPadding + actualWidth;
+    const leftEdgeOffset = pos.left - viewportPadding;
+    const rightEdgeOffset = pos.left + viewportPadding + actualWidth;
     if (leftEdgeOffset < viewportDimensions.left) {
       // left overflow
       delta.left = viewportDimensions.left - leftEdgeOffset;
@@ -545,7 +545,7 @@ Tooltip.prototype.getViewportAdjustedDelta = function(
 };
 
 Tooltip.prototype.getTitle = function() {
-  var title = this.element.getAttribute('data-original-title');
+  const title = this.element.getAttribute('data-original-title');
   if (title) {
     return title;
   } else {
@@ -617,7 +617,7 @@ Tooltip.prototype.destroy = function() {
 };
 
 Tooltip.prototype.getDelegateComponent = function(element) {
-  var component = tooltipComponentsByElement.get(element);
+  let component = tooltipComponentsByElement.get(element);
   if (!component) {
     component = new Tooltip(
       element,
@@ -630,26 +630,26 @@ Tooltip.prototype.getDelegateComponent = function(element) {
 };
 
 Tooltip.prototype.recalculatePosition = function() {
-  var tip = this.getTooltipElement();
+  const tip = this.getTooltipElement();
 
-  var placement =
+  let placement =
     typeof this.options.placement === 'function'
       ? this.options.placement.call(this, tip, this.element)
       : this.options.placement;
 
-  var autoToken = /\s?auto?\s?/i;
-  var autoPlace = autoToken.test(placement);
+  const autoToken = /\s?auto?\s?/i;
+  const autoPlace = autoToken.test(placement);
   if (autoPlace) placement = placement.replace(autoToken, '') || 'top';
 
   tip.classList.add(placement);
 
-  var pos = this.element.getBoundingClientRect();
-  var actualWidth = tip.offsetWidth;
-  var actualHeight = tip.offsetHeight;
+  const pos = this.element.getBoundingClientRect();
+  const actualWidth = tip.offsetWidth;
+  const actualHeight = tip.offsetHeight;
 
   if (autoPlace) {
-    var orgPlacement = placement;
-    var viewportDim = this.viewport.getBoundingClientRect();
+    const orgPlacement = placement;
+    const viewportDim = this.viewport.getBoundingClientRect();
 
     placement =
       placement === 'bottom' && pos.bottom + actualHeight > viewportDim.bottom
@@ -666,7 +666,7 @@ Tooltip.prototype.recalculatePosition = function() {
     tip.classList.add(placement);
   }
 
-  var calculatedOffset = this.getCalculatedOffset(
+  const calculatedOffset = this.getCalculatedOffset(
     placement,
     pos,
     actualWidth,
@@ -676,11 +676,11 @@ Tooltip.prototype.recalculatePosition = function() {
 };
 
 function extend() {
-  var args = Array.prototype.slice.apply(arguments);
-  var target = args.shift();
-  var source = args.shift();
+  const args = Array.prototype.slice.apply(arguments);
+  const target = args.shift();
+  let source = args.shift();
   while (source) {
-    for (var key of Object.getOwnPropertyNames(source)) {
+    for (const key of Object.getOwnPropertyNames(source)) {
       target[key] = source[key];
     }
     source = args.shift();

src/typescript.js

@@ -1,17 +1,17 @@
 'use strict';
 
-var _ = require('underscore-plus');
-var crypto = require('crypto');
-var path = require('path');
+const _ = require('underscore-plus');
+const crypto = require('crypto');
+const path = require('path');
 
-var defaultOptions = {
+const defaultOptions = {
   target: 1,
   module: 'commonjs',
   sourceMap: true
 };
 
-var TypeScriptSimple = null;
-var typescriptVersionDir = null;
+let TypeScriptSimple = null;
+let typescriptVersionDir = null;
 
 exports.shouldCompile = function() {
   return true;
@@ -19,7 +19,7 @@ exports.shouldCompile = function() {
 
 exports.getCachePath = function(sourceCode) {
   if (typescriptVersionDir == null) {
-    var version = require('typescript-simple/package.json').version;
+    const version = require('typescript-simple/package.json').version;
     typescriptVersionDir = path.join(
       'ts',
       createVersionAndOptionsDigest(version, defaultOptions)
@@ -44,7 +44,7 @@ exports.compile = function(sourceCode, filePath) {
     filePath = 'file:///' + path.resolve(filePath).replace(/\\/g, '/');
   }
 
-  var options = _.defaults({ filename: filePath }, defaultOptions);
+  const options = _.defaults({ filename: filePath }, defaultOptions);
   return new TypeScriptSimple(options, false).compile(sourceCode, filePath);
 };
 

src/view-registry.js

@@ -259,13 +259,13 @@ module.exports = class ViewRegistry {
     this.nextUpdatePromise = null;
     this.resolveNextUpdatePromise = null;
 
-    var writer = this.documentWriters.shift();
+    let writer = this.documentWriters.shift();
     while (writer) {
       writer();
       writer = this.documentWriters.shift();
     }
 
-    var reader = this.documentReaders.shift();
+    let reader = this.documentReaders.shift();
     this.documentReadInProgress = true;
     while (reader) {
       reader();