fix trivial cases of no-var

.eslintrc.json

@@ -18,10 +18,9 @@
     "@typescript-eslint/no-explicit-any": "off",
     "@typescript-eslint/no-this-alias": "off",
     "@typescript-eslint/no-unused-vars": ["warn", { "argsIgnorePattern": "^_" }],
+    "@typescript-eslint/no-empty-interface": "off",
 
     "eqeqeq": "off",
-    "no-var": "off",
-    "@typescript-eslint/no-empty-interface": "off",
     "@typescript-eslint/explicit-module-boundary-types": "off",
     "prefer-spread": "off",
     "prefer-rest-params": "off",

ui/@types/cash/index.d.ts

@@ -313,7 +313,7 @@ interface CashStatic {
 declare module 'cash' {
   export = $;
 }
-declare var $: CashStatic;
+declare const $: CashStatic;
 /* export default cash; */
 /* export { Cash, CashStatic, Ele as Element, Selector, Comparator, Context }; */
 /* end hacks */

ui/@types/lichess/index.d.ts

@@ -490,4 +490,4 @@ declare namespace PowerTip {
 
 declare module '@yaireo/tagify';
 
-declare var lichess: Lichess;
+declare const lichess: Lichess;

ui/analyse/src/forecast/forecastCtrl.ts

@@ -18,13 +18,11 @@ export function make(cfg: ForecastData, data: AnalyseData, redraw: () => void):
   }
 
   function findStartingWithNode(node: ForecastStep): ForecastStep[][] {
-    return forecasts.filter(function (fc) {
+    return forecasts.filter(fc => contains(fc, [node]));
-      return contains(fc, [node]);
-    });
   }
 
   function collides(fc1: ForecastStep[], fc2: ForecastStep[]): boolean {
-    for (var i = 0, max = Math.min(fc1.length, fc2.length); i < max; i++) {
+    for (let i = 0, max = Math.min(fc1.length, fc2.length); i < max; i++) {
       if (fc1[i].uci !== fc2[i].uci) {
         if (cfg.onMyTurn) return i !== 0 && i % 2 === 0;
         return i % 2 === 1;
@@ -74,9 +72,7 @@ export function make(cfg: ForecastData, data: AnalyseData, redraw: () => void):
   function isCandidate(fc: ForecastStep[]): boolean {
     fc = truncate(fc);
     if (!isLongEnough(fc)) return false;
-    var collisions = forecasts.filter(function (f) {
+    const collisions = forecasts.filter(f => contains(f, fc));
-      return contains(f, fc);
-    });
     if (collisions.length) return false;
     return true;
   }

ui/analyse/src/forecast/forecastView.ts

@@ -6,11 +6,11 @@ import { bind, dataIcon, spinner } from '../util';
 import { fixCrazySan } from 'chess';
 
 function onMyTurn(ctrl: AnalyseCtrl, fctrl: ForecastCtrl, cNodes: ForecastStep[]): VNode | undefined {
-  var firstNode = cNodes[0];
+  const firstNode = cNodes[0];
   if (!firstNode) return;
-  var fcs = fctrl.findStartingWithNode(firstNode);
+  const fcs = fctrl.findStartingWithNode(firstNode);
   if (!fcs.length) return;
-  var lines = fcs.filter(function (fc) {
+  const lines = fcs.filter(function (fc) {
     return fc.length > 1;
   });
   return h(

ui/analyse/src/nodeFinder.ts

@@ -16,7 +16,7 @@ export function nextGlyphSymbol(
   const len = mainline.length;
   if (!len) return;
   const fromIndex = fromPly - mainline[0].ply;
-  for (var i = 1; i < len; i++) {
+  for (let i = 1; i < len; i++) {
     const node = mainline[(fromIndex + i) % len];
     const found =
       node.ply % 2 === (color === 'white' ? 1 : 0) &&
@@ -32,11 +32,11 @@ export function nextGlyphSymbol(
 export function evalSwings(mainline: Tree.Node[], nodeFilter: (node: Tree.Node) => boolean): Tree.Node[] {
   const found: Tree.Node[] = [];
   const threshold = 0.1;
-  for (var i = 1; i < mainline.length; i++) {
+  for (let i = 1; i < mainline.length; i++) {
-    var node = mainline[i];
+    const node = mainline[i];
-    var prev = mainline[i - 1];
+    const prev = mainline[i - 1];
     if (nodeFilter(node) && node.eval && prev.eval) {
-      var diff = Math.abs(winningChances.povDiff('white', prev.eval, node.eval));
+      const diff = Math.abs(winningChances.povDiff('white', prev.eval, node.eval));
       if (diff > threshold && hasCompChild(prev)) found.push(node);
     }
   }

ui/analyse/src/pgnExport.ts

@@ -12,7 +12,7 @@ function renderNodesTxt(nodes: PgnNode[]): string {
   if (!nodes[0]) return '';
   if (!nodes[0].san) nodes = nodes.slice(1);
   if (!nodes[0]) return '';
-  var s = nodes[0].ply % 2 === 1 ? '' : Math.floor((nodes[0].ply + 1) / 2) + '... ';
+  let s = nodes[0].ply % 2 === 1 ? '' : Math.floor((nodes[0].ply + 1) / 2) + '... ';
   nodes.forEach(function (node, i) {
     if (node.ply === 0) return;
     if (node.ply % 2 === 1) s += (node.ply + 1) / 2 + '. ';
@@ -23,9 +23,9 @@ function renderNodesTxt(nodes: PgnNode[]): string {
 }
 
 export function renderFullTxt(ctrl: AnalyseCtrl): string {
-  var g = ctrl.data.game;
+  const g = ctrl.data.game;
-  var txt = renderNodesTxt(ctrl.tree.getNodeList(ctrl.path));
+  let txt = renderNodesTxt(ctrl.tree.getNodeList(ctrl.path));
-  var tags: Array<[string, string]> = [];
+  const tags: Array<[string, string]> = [];
   if (g.variant.key !== 'standard') tags.push(['Variant', g.variant.name]);
   if (g.initialFen && g.initialFen !== initialFen) tags.push(['FEN', g.initialFen]);
   if (tags.length)

ui/analyse/src/retrospect/retroCtrl.ts

@@ -116,11 +116,11 @@ export function make(root: AnalyseCtrl, color: Color): RetroCtrl {
   }
 
   function checkCeval(): void {
-    var node = root.node,
+    const node = root.node,
       cur = current();
     if (!cur || feedback() !== 'eval' || cur.fault.node.ply !== node.ply) return;
     if (isCevalReady(node)) {
-      var diff = winningChances.povDiff(color, node.ceval!, cur.prev.node.eval);
+      const diff = winningChances.povDiff(color, node.ceval!, cur.prev.node.eval);
       if (diff > -0.035) onWin();
       else onFail();
     }

ui/analyse/src/socket.ts

@@ -69,7 +69,7 @@ export function make(send: SocketSend, ctrl: AnalyseCtrl): Socket {
   }
 
   function addStudyData(req: Req, isWrite = false): void {
-    var c = currentChapterId();
+    const c = currentChapterId();
     if (c) {
       req.ch = c;
       if (isWrite) {

ui/analyse/src/study/practice/studyPracticeSuccess.ts

@@ -17,7 +17,7 @@ function isWinning(node: Tree.Node, goalCp: number, color: Color): boolean | nul
 function myMateIn(node: Tree.Node, color: Color): number | boolean | null {
   if (!hasSolidEval(node)) return null;
   if (!node.ceval!.mate) return false;
-  var mateIn = node.ceval!.mate! * (color === 'white' ? 1 : -1);
+  const mateIn = node.ceval!.mate! * (color === 'white' ? 1 : -1);
   return mateIn > 0 ? mateIn : false;
 }
 

ui/analyse/src/study/studyMembers.ts

@@ -161,7 +161,7 @@ export function view(ctrl: StudyCtrl): VNode {
     isOwner = members.isOwner();
 
   function username(member: StudyMember) {
-    var u = member.user;
+    const u = member.user;
     return h(
       'span.user-link.ulpt',
       {

ui/analyse/src/util.ts

@@ -152,13 +152,13 @@ export function toYouTubeEmbed(url: string): string | undefined {
 
 function toYouTubeEmbedUrl(url: string) {
   if (!url) return;
-  var m = url.match(
+  const m = url.match(
     /(?:https?:\/\/)?(?:www\.)?(?:youtube\.com|youtu\.be)\/(?:watch)?(?:\?v=)?([^"&?\/ ]{11})(?:\?|&|)(\S*)/i
   );
   if (!m) return;
-  var start = 0;
+  let start = 0;
   m[2].split('&').forEach(function (p) {
-    var s = p.split('=');
+    const s = p.split('=');
     if (s[0] === 't' || s[0] === 'start') {
       if (s[1].match(/^\d+$/)) start = parseInt(s[1]);
       else {
@@ -167,7 +167,7 @@ function toYouTubeEmbedUrl(url: string) {
       }
     }
   });
-  var params = 'modestbranding=1&rel=0&controls=2&iv_load_policy=3' + (start ? '&start=' + start : '');
+  const params = 'modestbranding=1&rel=0&controls=2&iv_load_policy=3' + (start ? '&start=' + start : '');
   return 'https://www.youtube.com/embed/' + m[1] + '?' + params;
 }
 

ui/challenge/src/ctrl.ts

@@ -34,8 +34,8 @@ export default function (opts: ChallengeOpts, data: ChallengeData, redraw: () =>
   }
 
   function showUser(user: ChallengeUser) {
-    var rating = user.rating + (user.provisional ? '?' : '');
+    const rating = user.rating + (user.provisional ? '?' : '');
-    var fullName = (user.title ? user.title + ' ' : '') + user.name;
+    const fullName = (user.title ? user.title + ' ' : '') + user.name;
     return fullName + ' (' + rating + ')';
   }
 

ui/cli/src/main.ts

@@ -24,7 +24,7 @@ function execute(q: string) {
 }
 
 function command(q: string) {
-  var parts = q.split(' '),
+  const parts = q.split(' '),
     exec = parts[0];
 
   const is = function (commands: string) {

ui/dasher/src/background.ts

@@ -131,7 +131,7 @@ function applyBackground(data: BackgroundData, list: Background[]) {
     sheet = key == 'darkBoard' ? 'dark' : key;
   $('body').data('theme', sheet);
   $('link[href*=".' + prev + '."]').each(function (this: HTMLLinkElement) {
-    var link = document.createElement('link') as HTMLLinkElement;
+    const link = document.createElement('link') as HTMLLinkElement;
     link.rel = 'stylesheet';
     link.href = this.href.replace('.' + prev + '.', '.' + sheet + '.');
     link.onload = () => setTimeout(() => this.remove(), 100);

ui/dgt/src/play.ts

@@ -20,7 +20,7 @@ export default function (token: string) {
     : 'san';
   const speechSynthesisOn = localStorage.getItem('dgt-speech-synthesis') == 'true';
   const voice = localStorage.getItem('dgt-speech-voice');
-  var keywords = {
+  let keywords = {
     K: 'King',
     Q: 'Queen',
     R: 'Rook',
@@ -56,15 +56,15 @@ export default function (token: string) {
   /**
    * GLOBAL VARIABLES - Lichess Connectivity
    */
-  var time = new Date(); //A Global time object
+  const time = new Date(); //A Global time object
-  var currentGameId = ''; //Track which is the current Game, in case there are several open games
+  let currentGameId = ''; //Track which is the current Game, in case there are several open games
-  var currentGameColor = ''; //Track which color is being currently played by the player. 'white' or 'black'
+  let currentGameColor = ''; //Track which color is being currently played by the player. 'white' or 'black'
-  var me: { id: string; username: string }; //Track my information
+  let me: { id: string; username: string }; //Track my information
-  var gameInfoMap = new Map(); //A collection of key values to store game immutable information of all open games
+  const gameInfoMap = new Map(); //A collection of key values to store game immutable information of all open games
-  var gameStateMap = new Map(); //A collection of key values to store the changing state of all open games
+  const gameStateMap = new Map(); //A collection of key values to store the changing state of all open games
-  var gameConnectionMap = new Map<string, { connected: boolean; lastEvent: number }>(); //A collection of key values to store the network status of a game
+  const gameConnectionMap = new Map<string, { connected: boolean; lastEvent: number }>(); //A collection of key values to store the network status of a game
-  var gameChessBoardMap = new Map<string, Chess>(); //A collection of chessops Boards representing the current board of the games
+  const gameChessBoardMap = new Map<string, Chess>(); //A collection of chessops Boards representing the current board of the games
-  var eventSteamStatus = { connected: false, lastEvent: time.getTime() }; //An object to store network status of the main eventStream
+  let eventSteamStatus = { connected: false, lastEvent: time.getTime() }; //An object to store network status of the main eventStream
   const keywordsBase = [
     'white',
     'black',
@@ -86,20 +86,20 @@ export default function (token: string) {
     'illegal',
     'move',
   ];
-  var lastSanMove: { player: string; move: string; by: string }; //Track last move in SAN format. This is because there is no easy way to keep history of san moves
+  let lastSanMove: { player: string; move: string; by: string }; //Track last move in SAN format. This is because there is no easy way to keep history of san moves
   /**
    * Global Variables for DGT Board Connection (JACM)
    */
-  var localBoard: Chess = startingPosition(); //Board with valid moves played on Lichess and DGT Board. May be half move behind Lichess or half move in advance
+  let localBoard: Chess = startingPosition(); //Board with valid moves played on Lichess and DGT Board. May be half move behind Lichess or half move in advance
-  var DGTgameId = ''; //Used to track if DGT board was setup already with the lichess currentGameId
+  let DGTgameId = ''; //Used to track if DGT board was setup already with the lichess currentGameId
-  var boards = Array<{ serialnr: string; state: string }>(); //An array to store all the board recognized by DGT LiveChess
+  let boards = Array<{ serialnr: string; state: string }>(); //An array to store all the board recognized by DGT LiveChess
-  var liveChessConnection: WebSocket; //Connection Object to LiveChess through websocket
+  let liveChessConnection: WebSocket; //Connection Object to LiveChess through websocket
-  var isLiveChessConnected = false; //Used to track if a board there is a connection to DGT Live Chess
+  let isLiveChessConnected = false; //Used to track if a board there is a connection to DGT Live Chess
-  var currentSerialnr = '0'; //Public property to store the current serial number of the DGT Board in case there is more than one
+  let currentSerialnr = '0'; //Public property to store the current serial number of the DGT Board in case there is more than one
   //subscription stores the information about the board being connected, most importantly the serialnr
-  var subscription = { id: 2, call: 'subscribe', param: { feed: 'eboardevent', id: 1, param: { serialnr: '' } } };
+  const subscription = { id: 2, call: 'subscribe', param: { feed: 'eboardevent', id: 1, param: { serialnr: '' } } };
-  var lastLegalParam: { board: string; san: string[] }; //This can help prevent duplicate moves from LiveChess being detected as move from the other side, like a duplicate O-O
+  let lastLegalParam: { board: string; san: string[] }; //This can help prevent duplicate moves from LiveChess being detected as move from the other side, like a duplicate O-O
-  var lastLiveChessBoard: string; //Store last Board received by LiveChess
+  let lastLiveChessBoard: string; //Store last Board received by LiveChess
   /***
    * Bind console output to HTML pre Element
    */
@@ -121,7 +121,7 @@ export default function (token: string) {
       console[name] = function () {
         //Return a promise so execution is not delayed by string manipulation
         return new Promise<void>(resolve => {
-          var output = '';
+          let output = '';
           for (let i = 0; i < arguments.length; i++) {
             const arg = arguments[i];
             if (arg == '*' || arg == ':') {
@@ -236,12 +236,12 @@ export default function (token: string) {
       //Update connection status
       eventSteamStatus = { connected: true, lastEvent: time.getTime() };
       //Response may contain several JSON objects on the same chunk separated by \n . This may create an empty element at the end.
-      var jsonArray = value ? decoder.decode(value).split('\n') : [];
+      const jsonArray = value ? decoder.decode(value).split('\n') : [];
       for (let i = 0; i < jsonArray.length; i++) {
         //Skip empty elements that may have happened witht the .split('\n')
         if (jsonArray[i].length > 2) {
           try {
-            var data = JSON.parse(jsonArray[i]);
+            const data = JSON.parse(jsonArray[i]);
             //JSON data found, let's check if this is a game that started. field type is mandatory except on http 4xx
             if (data.type == 'gameStart') {
               if (verbose) console.log('connectToEventStream - gameStart event arrived. GameId: ' + data.game.id);
@@ -333,12 +333,12 @@ export default function (token: string) {
       //Update connection status
       gameConnectionMap.set(gameId, { connected: true, lastEvent: time.getTime() });
       //Response may contain several JSON objects on the same chunk separated by \n . This may create an empty element at the end.
-      var jsonArray = decoder.decode(value)!.split('\n');
+      const jsonArray = decoder.decode(value)!.split('\n');
       for (let i = 0; i < jsonArray.length; i++) {
         //Skip empty elements that may have happened witht the .split('\n')
         if (jsonArray[i].length > 2) {
           try {
-            var data = JSON.parse(jsonArray[i]);
+            const data = JSON.parse(jsonArray[i]);
             //The first line is always of type gameFull.
             if (data.type == 'gameFull') {
               if (!verbose) console.clear();
@@ -397,7 +397,7 @@ export default function (token: string) {
    */
   function formattedTimer(timer: number): string {
     // Pad function to pad with 0 to 2 or 3 digits, default is 2
-    var pad = (n: number, z = 2) => `00${n}`.slice(-z);
+    const pad = (n: number, z = 2) => `00${n}`.slice(-z);
     return pad((timer / 3.6e6) | 0) + ':' + pad(((timer % 3.6e6) / 6e4) | 0) + ':' + pad(((timer % 6e4) / 1000) | 0); //+ '.' + pad(timer % 1000, 3);
   }
 
@@ -438,7 +438,7 @@ export default function (token: string) {
   async function chooseCurrentGame() {
     //Determine new value for currentGameId. First create an array with only the started games
     //So then there is none or more than one started game
-    var playableGames = playableGamesArray();
+    const playableGames = playableGamesArray();
     //If there is only one started game, then its easy
     /*
     if (playableGames.length == 1) {
@@ -521,16 +521,16 @@ export default function (token: string) {
    */
   function initializeChessBoard(gameId: string, data: { initialFen: string; state: { moves: string } }) {
     try {
-      var initialFen: string = INITIAL_FEN;
+      let initialFen: string = INITIAL_FEN;
       if (data.initialFen != 'startpos') initialFen = data.initialFen;
-      var setup = parseFen(initialFen).unwrap();
+      const setup = parseFen(initialFen).unwrap();
-      var chess: Chess = Chess.fromSetup(setup).unwrap();
+      const chess: Chess = Chess.fromSetup(setup).unwrap();
-      var moves = data.state.moves.split(' ');
+      const moves = data.state.moves.split(' ');
       for (let i = 0; i < moves.length; i++) {
         if (moves[i] != '') {
           //Make any move that may have been already played on the ChessBoard. Useful when reconnecting
-          var uciMove = <NormalMove>parseUci(moves[i]);
+          const uciMove = <NormalMove>parseUci(moves[i]);
-          var normalizedMove = chess.normalizeMove(uciMove); //This is because chessops uses UCI_960
+          const normalizedMove = chess.normalizeMove(uciMove); //This is because chessops uses UCI_960
           if (normalizedMove && chess.isLegal(normalizedMove)) chess.play(normalizedMove);
         }
       }
@@ -553,9 +553,9 @@ export default function (token: string) {
    */
   function updateChessBoard(gameId: string, currentState: { moves: string }, newState: { moves: string }) {
     try {
-      var chess = gameChessBoardMap.get(gameId);
+      const chess = gameChessBoardMap.get(gameId);
       if (chess) {
-        var pendingMoves: string;
+        let pendingMoves: string;
         if (!currentState.moves) {
           //No prior moves. Use the new moves
           pendingMoves = newState.moves;
@@ -563,12 +563,12 @@ export default function (token: string) {
           //Get all the moves on the newState that are not present on the currentState
           pendingMoves = newState.moves.substring(currentState.moves.length, newState.moves.length);
         }
-        var moves = pendingMoves.split(' ');
+        const moves = pendingMoves.split(' ');
         for (let i = 0; i < moves.length; i++) {
           if (moves[i] != '') {
             //Make the new move
-            var uciMove = <NormalMove>parseUci(moves[i]);
+            const uciMove = <NormalMove>parseUci(moves[i]);
-            var normalizedMove = chess.normalizeMove(uciMove); //This is because chessops uses UCI_960
+            const normalizedMove = chess.normalizeMove(uciMove); //This is because chessops uses UCI_960
             if (normalizedMove && chess.isLegal(normalizedMove)) {
               //This is a good chance to get the move in SAN format
               if (chess.turn == 'black')
@@ -622,7 +622,7 @@ export default function (token: string) {
     Timer: string;
     'Last Move': string;
   }> {
-    var playableGames: Array<{
+    const playableGames: Array<{
       gameId: string;
       versus: string;
       'vs rating': string;
@@ -630,17 +630,17 @@ export default function (token: string) {
       Timer: string;
       'Last Move': string;
     }> = [];
-    var keys = Array.from(gameConnectionMap.keys());
+    const keys = Array.from(gameConnectionMap.keys());
     //The for each iterator is not used since we don't want to continue execution. We want a synchronous result
     //for (let [gameId, networkState] of gameConnectionMap) {
     //    if (gameConnectionMap.get(gameId).connected && gameStateMap.get(gameId).status == "started") {
-    for (var i = 0; i < keys.length; i++) {
+    for (let i = 0; i < keys.length; i++) {
       if (gameConnectionMap.get(keys[i])?.connected && gameStateMap.get(keys[i])?.status == 'started') {
         //Game is good for commands
-        var gameInfo = gameInfoMap.get(keys[i]);
+        const gameInfo = gameInfoMap.get(keys[i]);
         //var gameState = gameStateMap.get(keys[i]);
-        var lastMove = getLastUCIMove(keys[i]);
+        const lastMove = getLastUCIMove(keys[i]);
-        var versus =
+        const versus =
           gameInfo.black.id == me.id
             ? (gameInfo.white.title !== null ? gameInfo.white.title : '@') + ' ' + gameInfo.white.name
             : (gameInfo.black.title !== null ? gameInfo.black.title : '@') + ' ' + gameInfo.black.name;
@@ -669,9 +669,9 @@ export default function (token: string) {
    */
   function logGameState(gameId: string) {
     if (gameStateMap.has(gameId) && gameInfoMap.has(gameId)) {
-      var gameInfo = gameInfoMap.get(gameId);
+      const gameInfo = gameInfoMap.get(gameId);
-      var gameState = gameStateMap.get(gameId);
+      const gameState = gameStateMap.get(gameId);
-      var lastMove = getLastUCIMove(gameId);
+      const lastMove = getLastUCIMove(gameId);
       console.log(''); //process.stdout.write("\n"); Changed to support browser
       /* Log before migrating to browser
       if (verbose) console.table({
@@ -682,7 +682,7 @@ export default function (token: string) {
         'Last Move': { white: (lastMove.player == 'white' ? lastMove.move : '?'), black: (lastMove.player == 'black' ? lastMove.move : '?'), game: lastMove.player },
       });
       */
-      var innerTable =
+      const innerTable =
         `<table class="dgt-table"><tr><th> - </th><th>Title</th><th>Username</th><th>Rating</th><th>Timer</th><th>Last Move</th><th>gameId: ${gameInfo.id}</th></tr>` +
         `<tr><td>White</td><td>${gameInfo.white.title !== null ? gameInfo.white.title : '@'}</td><td>${
           gameInfo.white.name
@@ -747,11 +747,11 @@ export default function (token: string) {
    */
   function getLastUCIMove(gameId: string): { player: string; move: string; by: string } {
     if (gameStateMap.has(gameId) && gameInfoMap.has(gameId)) {
-      var gameInfo = gameInfoMap.get(gameId);
+      const gameInfo = gameInfoMap.get(gameId);
-      var gameState = gameStateMap.get(gameId);
+      const gameState = gameStateMap.get(gameId);
       //This is the original code that does not used chessops objects and can be used to get the UCI move but not SAN.
       if (String(gameState.moves).length > 1) {
-        var moves = gameState.moves.split(' ');
+        const moves = gameState.moves.split(' ');
         if (verbose)
           console.log(`getLastUCIMove - ${moves.length} moves detected. Last one: ${moves[moves.length - 1]}`);
         if (moves.length % 2 == 0) return { player: 'black', move: moves[moves.length - 1], by: gameInfo.black.id };
@@ -772,7 +772,7 @@ export default function (token: string) {
   function announcePlay(lastMove: { player: string; move: string; by: string }) {
     //ttsSay(lastMove.player);
     //Now play it using text to speech library
-    var moveText: string;
+    let moveText: string;
     if (announceMoveFormat && announceMoveFormat.toLowerCase() == 'san' && lastSanMove) {
       moveText = lastSanMove.move;
       ttsSay(replaceKeywords(padBeforeNumbers(lastSanMove.move)));
@@ -810,7 +810,7 @@ export default function (token: string) {
   }
 
   async function connectToLiveChess() {
-    var SANMove: string; //a move in san format returned by liveChess
+    let SANMove: string; //a move in san format returned by liveChess
     //Open the WebSocket
     liveChessConnection = new WebSocket(liveChessURL ? liveChessURL : 'ws://localhost:1982/api/v1.0');
 
@@ -836,7 +836,7 @@ export default function (token: string) {
 
     liveChessConnection.onmessage = async e => {
       if (verbose) console.info('Websocket onmessage with data:' + e.data);
-      var message = JSON.parse(e.data);
+      const message = JSON.parse(e.data);
       //Store last board if received
       if (message.response == 'feed' && !!message.param.board) {
         lastLiveChessBoard = message.param.board;
@@ -877,7 +877,7 @@ export default function (token: string) {
         //Received move from board
         if (verbose) console.info('onmessage - san: ' + message.param.san);
         //get last move known to lichess and avoid calling multiple times this function
-        var lastMove = getLastUCIMove(currentGameId);
+        const lastMove = getLastUCIMove(currentGameId);
         if (message.param.san.length == 0) {
           if (verbose) console.info('onmessage - san is empty');
         } else if (
@@ -891,7 +891,7 @@ export default function (token: string) {
           //A move was received
           //Get all the moves on the param.san that are not present on lastLegalParam.san
           //it is possible to receive two new moves on the message. Don't assume only the last move is pending.
-          var movesToProcess = 1;
+          let movesToProcess = 1;
           if (lastLegalParam !== undefined) movesToProcess = message.param.san.length - lastLegalParam.san.length;
           //Check border case in which DGT Board LiveChess detects the wrong move while pieces are still on the air
           if (movesToProcess > 1) {
@@ -900,7 +900,7 @@ export default function (token: string) {
             if (localBoard.turn == currentGameColor) {
               //If more than one move is received when its the DGT board player's turn this may be a invalid move
               //Move will be quarentined by 2.5 seconds
-              var quarentinedlastLegalParam = lastLegalParam;
+              const quarentinedlastLegalParam = lastLegalParam;
               await sleep(2500);
               //Check if a different move was recevied and processed during quarentine
               if (JSON.stringify(lastLegalParam.san) != JSON.stringify(quarentinedlastLegalParam.san)) {
@@ -1027,8 +1027,8 @@ export default function (token: string) {
    * @param chess - The chessops Chess object with the position on Lichess
    */
   async function sendBoardToLiveChess(chess: Chess) {
-    var fen = makeFen(chess.toSetup());
+    const fen = makeFen(chess.toSetup());
-    var setupMessage = {
+    const setupMessage = {
       id: 3,
       call: 'call',
       param: {
@@ -1080,7 +1080,7 @@ export default function (token: string) {
       await chooseCurrentGame();
     }
     //Now send the move
-    var command = makeUci(boardMove);
+    const command = makeUci(boardMove);
     sendMove(currentGameId, command);
   }
 
@@ -1100,7 +1100,7 @@ export default function (token: string) {
     if (uciMove.length > 1) {
       //Log intention
       //Automatically decline draws when making a move
-      var url = `/api/board/game/${gameId}/move/${uciMove}?offeringDraw=false`;
+      const url = `/api/board/game/${gameId}/move/${uciMove}?offeringDraw=false`;
       if (verbose) console.log('sendMove - About to call ' + url);
       fetch(url, {
         method: 'POST',
@@ -1133,7 +1133,7 @@ export default function (token: string) {
    * @returns {String} - The San move with words instead of letters
    */
   function replaceKeywords(sanMove) {
-    var extendedSanMove = sanMove;
+    let extendedSanMove = sanMove;
     for (let i = 0; i < keywordsBase.length; i++) {
       try {
         extendedSanMove = extendedSanMove.replace(keywordsBase[i], ' ' + keywords[keywordsBase[i]].toLowerCase() + ' ');
@@ -1151,7 +1151,7 @@ export default function (token: string) {
    * @returns {String} - The move with spaces before the numbers for better TTS
    */
   function padBeforeNumbers(moveString: string) {
-    var paddedMoveString = '';
+    let paddedMoveString = '';
     for (const c of moveString) {
       Number.isInteger(+c) ? (paddedMoveString += ` ${c} `) : (paddedMoveString += c);
     }
@@ -1165,9 +1165,9 @@ export default function (token: string) {
     //Check if Voice is disabled
     if (verbose) console.log('TTS - for text: ' + text);
     if (!speechSynthesisOn) return;
-    var utterThis = new SpeechSynthesisUtterance(text);
+    const utterThis = new SpeechSynthesisUtterance(text);
-    var selectedOption = voice;
+    const selectedOption = voice;
-    var availableVoices = speechSynthesis.getVoices();
+    const availableVoices = speechSynthesis.getVoices();
     for (let i = 0; i < availableVoices.length; i++) {
       if (availableVoices[i].name === selectedOption) {
         utterThis.voice = availableVoices[i];
@@ -1192,14 +1192,14 @@ export default function (token: string) {
    */
   function compareMoves(lastMove: string, moveObject: NormalMove): boolean {
     try {
-      var uciMove = makeUci(moveObject);
+      const uciMove = makeUci(moveObject);
       if (verbose) console.log(`Comparing ${lastMove} with ${uciMove}`);
       if (lastMove == uciMove) {
         //it's the same move
         return true;
       }
       if (verbose) console.log('Moves look different. Check if this is a castling mismatch.');
-      var castlingSide = localBoard.castlingSide(moveObject);
+      const castlingSide = localBoard.castlingSide(moveObject);
       if (lastMove.length > 2 && castlingSide) {
         //It was a castling so it still may be the same move
         if (lastMove.startsWith(uciMove.substring(0, 2))) {

ui/lobby/src/setup.ts

@@ -315,7 +315,7 @@ export default class Setup {
         });
       });
       $daysInput.each(function (this: HTMLInputElement) {
-        var $input = $(this),
+        const $input = $(this),
           $value = $input.siblings('span'),
           $range = $input.siblings('.range');
         $value.text($input.val() as string);
@@ -370,7 +370,7 @@ export default class Setup {
     }
     $timeModeSelect
       .on('change', function (this: HTMLElement) {
-        var timeMode = $(this).val();
+        const timeMode = $(this).val();
         $form.find('.time_choice, .increment_choice').toggle(timeMode == '1');
         $form.find('.days_choice').toggle(timeMode == '2');
         toggleButtons();
@@ -378,11 +378,11 @@ export default class Setup {
       })
       .trigger('change');
 
-    var validateFen = debounce(() => {
+    const validateFen = debounce(() => {
       $fenInput.removeClass('success failure');
-      var fen = $fenInput.val() as string;
+      const fen = $fenInput.val() as string;
       if (fen) {
-        var [path, params] = $fenInput.parent().data('validate-url').split('?'); // Separate "strict=1" for AI match
+        const [path, params] = $fenInput.parent().data('validate-url').split('?'); // Separate "strict=1" for AI match
         xhr.text(xhr.url(path, { fen }) + (params ? `&${params}` : '')).then(
           data => {
             $fenInput.addClass('success');
@@ -406,7 +406,7 @@ export default class Setup {
     if (forceFormPosition) $variantSelect.val('' + 3);
     $variantSelect
       .on('change', function (this: HTMLElement) {
-        var isFen = $(this).val() == '3';
+        const isFen = $(this).val() == '3';
         $fenPosition.toggle(isFen);
         $modeChoicesWrap.toggle(!isFen);
         if (isFen) {
@@ -421,7 +421,7 @@ export default class Setup {
     $modeChoices.on('change', save);
 
     $form.find('div.level').each(function (this: HTMLElement) {
-      var $infos = $(this).find('.ai_info > div');
+      const $infos = $(this).find('.ai_info > div');
       $(this)
         .find('label')
         .on('mouseenter', function (this: HTMLElement) {
@@ -433,7 +433,7 @@ export default class Setup {
       $(this)
         .find('#config_level')
         .on('mouseleave', function (this: HTMLElement) {
-          var level = $(this).find('input:checked').val();
+          const level = $(this).find('input:checked').val();
           $infos
             .hide()
             .filter('.sf_level_' + level)

ui/notify/src/renderers.ts

@@ -167,7 +167,7 @@ function generic(n: Notification, url: string | undefined, icon: string, content
 }
 
 function drawTime(n: Notification) {
-  var date = new Date(n.date);
+  const date = new Date(n.date);
   return h(
     'time.timeago',
     {

ui/nvui/src/chess.ts

@@ -204,7 +204,7 @@ export function lastCaptured(movesGenerator: () => string[], pieceStyle: PieceSt
   }
   const oldSplitFen = oldFen.split(' ')[0];
   const newSplitFen = newFen.split(' ')[0];
-  for (var p of 'kKqQrRbBnNpP') {
+  for (const p of 'kKqQrRbBnNpP') {
     const diff = oldSplitFen.split(p).length - 1 - (newSplitFen.split(p).length - 1);
     const pcolor = p.toUpperCase() === p ? 'white' : 'black';
     if (diff === 1) {

ui/puzzle/src/view/side.ts

@@ -5,7 +5,7 @@ import { numberFormat } from 'common/number';
 import PuzzleStreak from '../streak';
 
 export function puzzleBox(ctrl: Controller): VNode {
-  var data = ctrl.getData();
+  const data = ctrl.getData();
   return h('div.puzzle__side__metas', [puzzleInfos(ctrl, data.puzzle), gameInfos(ctrl, data.game, data.puzzle)]);
 }
 

ui/puzzle/src/view/tree.ts

@@ -21,8 +21,8 @@ interface Glyph {
 }
 
 const autoScroll = throttle(150, (ctrl: Controller, el) => {
-  var cont = el.parentNode;
+  const cont = el.parentNode;
-  var target = el.querySelector('.active');
+  const target = el.querySelector('.active');
   if (!target) {
     cont.scrollTop = ctrl.vm.path === treePath.root ? 0 : 99999;
     return;

ui/round/src/plugins/sanWriter.ts

@@ -14,9 +14,9 @@ function square(name: string) {
 }
 
 function squareDist(a: number, b: number) {
-  var x1 = a & 7,
+  const x1 = a & 7,
     x2 = b & 7;
-  var y1 = a >> 3,
+  const y1 = a >> 3,
     y2 = b >> 3;
   return Math.max(Math.abs(x1 - x2), Math.abs(y1 - y2));
 }
@@ -63,15 +63,15 @@ function knightMovesTo(s: number) {
   });
 }
 
-var ROOK_DELTAS = [8, 1, -8, -1];
+const ROOK_DELTAS = [8, 1, -8, -1];
-var BISHOP_DELTAS = [9, -9, 7, -7];
+const BISHOP_DELTAS = [9, -9, 7, -7];
-var QUEEN_DELTAS = ROOK_DELTAS.concat(BISHOP_DELTAS);
+const QUEEN_DELTAS = ROOK_DELTAS.concat(BISHOP_DELTAS);
 
 function slidingMovesTo(s: number, deltas: number[], board: Board): number[] {
-  var result: number[] = [];
+  const result: number[] = [];
   deltas.forEach(function (delta) {
     for (
-      var square = s + delta;
+      let square = s + delta;
       square >= 0 && square < 64 && squareDist(square, square - delta) === 1;
       square += delta
     ) {
@@ -85,12 +85,12 @@ function slidingMovesTo(s: number, deltas: number[], board: Board): number[] {
 function sanOf(board: Board, uci: string) {
   if (uci.includes('@')) return fixCrazySan(uci);
 
-  var move = decomposeUci(uci);
+  const move = decomposeUci(uci);
-  var from = square(move[0]);
+  const from = square(move[0]);
-  var to = square(move[1]);
+  const to = square(move[1]);
-  var p = board.pieces[from];
+  const p = board.pieces[from];
-  var d = board.pieces[to];
+  const d = board.pieces[to];
-  var pt = board.pieces[from].toLowerCase();
+  const pt = board.pieces[from].toLowerCase();
 
   // pawn moves
   if (pt === 'p') {
@@ -110,16 +110,16 @@ function sanOf(board: Board, uci: string) {
   var san = pt.toUpperCase();
 
   // disambiguate normal moves
-  var candidates: number[] = [];
+  let candidates: number[] = [];
   if (pt == 'k') candidates = kingMovesTo(to);
   else if (pt == 'n') candidates = knightMovesTo(to);
   else if (pt == 'r') candidates = slidingMovesTo(to, ROOK_DELTAS, board);
   else if (pt == 'b') candidates = slidingMovesTo(to, BISHOP_DELTAS, board);
   else if (pt == 'q') candidates = slidingMovesTo(to, QUEEN_DELTAS, board);
 
-  var rank = false,
+  let rank = false,
     file = false;
-  for (var i = 0; i < candidates.length; i++) {
+  for (let i = 0; i < candidates.length; i++) {
     if (candidates[i] === from || board.pieces[candidates[i]] !== p) continue;
     if (from >> 3 === candidates[i] >> 3) file = true;
     if ((from & 7) === (candidates[i] & 7)) rank = true;
@@ -135,10 +135,10 @@ function sanOf(board: Board, uci: string) {
 }
 
 export function sanWriter(fen: string, ucis: string[]): SanToUci {
-  var board = readFen(fen);
+  const board = readFen(fen);
-  var sans: SanToUci = {};
+  const sans: SanToUci = {};
   ucis.forEach(function (uci) {
-    var san = sanOf(board, uci);
+    const san = sanOf(board, uci);
     sans[san] = uci;
     if (san.includes('x')) sans[san.replace('x', '')] = uci;
   });

ui/round/src/promotion.ts

@@ -110,9 +110,9 @@ function renderPromotion(
   color: Color,
   orientation: Color
 ): MaybeVNode {
-  var left = (7 - key2pos(dest)[0]) * 12.5;
+  let left = (7 - key2pos(dest)[0]) * 12.5;
   if (orientation === 'white') left = 87.5 - left;
-  var vertical = color === orientation ? 'top' : 'bottom';
+  const vertical = color === orientation ? 'top' : 'bottom';
 
   return h(
     'div#promotion-choice.' + vertical,
@@ -126,7 +126,7 @@ function renderPromotion(
       }),
     },
     roles.map((serverRole, i) => {
-      var top = (color === orientation ? i : 7 - i) * 12.5;
+      const top = (color === orientation ? i : 7 - i) * 12.5;
       return h(
         'square',
         {

ui/site/src/checkout.ts

@@ -1,12 +1,12 @@
 import * as xhr from 'common/xhr';
 
 export default function (publicKey: string) {
-  var $checkout = $('div.plan_checkout');
+  const $checkout = $('div.plan_checkout');
-  var lifetime = {
+  const lifetime = {
     cents: parseInt($checkout.data('lifetime-cents')),
     usd: $checkout.data('lifetime-usd'),
   };
-  var min = 100,
+  const min = 100,
     max = 100 * 100000;
 
   if (location.hash === '#onetime') $('#freq_onetime').trigger('click');
@@ -22,7 +22,7 @@ export default function (publicKey: string) {
     $checkout.find('#plan_monthly_1000').trigger('click');
 
   const selectAmountGroup = function () {
-    var freq = getFreq();
+    const freq = getFreq();
     $checkout.find('.amount_fixed').toggleClass('none', freq != 'lifetime');
     $checkout.find('.amount_choice').toggleClass('none', freq == 'lifetime');
   };
@@ -38,7 +38,7 @@ export default function (publicKey: string) {
     } catch (e) {
       return false;
     }
-    var cents = Math.round(amount * 100);
+    let cents = Math.round(amount * 100);
     if (!cents) {
       $(this).text($(this).data('trans-other'));
       $checkout.find('#plan_monthly_1000').trigger('click');
@@ -46,7 +46,7 @@ export default function (publicKey: string) {
     }
     if (cents < min) cents = min;
     else if (cents > max) cents = max;
-    var usd = '$' + cents / 100;
+    const usd = '$' + cents / 100;
     $(this).text(usd);
     $(this).siblings('input').data('amount', cents).data('usd', usd);
   });
@@ -56,8 +56,8 @@ export default function (publicKey: string) {
       cents =
         freq == 'lifetime' ? lifetime.cents : parseInt($checkout.find('group.amount input:checked').data('amount'));
     if (!cents || cents < min || cents > max) return;
-    var amount = cents / 100;
+    const amount = cents / 100;
-    var $form = $checkout.find('form.paypal_checkout.' + freq);
+    const $form = $checkout.find('form.paypal_checkout.' + freq);
     $form.find('input.amount').val('' + amount);
     ($form[0] as HTMLFormElement).submit();
     $checkout.find('.service').html(lichess.spinnerHtml);

ui/site/src/coachForm.ts

@@ -5,14 +5,14 @@ import spinnerHtml from './component/spinner';
 import Tagify from '@yaireo/tagify';
 
 lichess.load.then(() => {
-  var $editor = $('.coach-edit');
+  const $editor = $('.coach-edit');
 
-  var todo = (function () {
+  const todo = (function () {
-    var $overview = $editor.find('.overview');
+    const $overview = $editor.find('.overview');
-    var $el = $overview.find('.todo');
+    const $el = $overview.find('.todo');
-    var $listed = $editor.find('#form3-listed');
+    const $listed = $editor.find('#form3-listed');
 
-    var must = [
+    const must = [
       {
         html: '<a href="/account/profile">Complete your lichess profile</a>',
         check() {
@@ -50,7 +50,7 @@ lichess.load.then(() => {
       const points: Cash[] = must.filter(o => !o.check()).map(o => $('<li>').html(o.html));
       const $ul = $el.find('ul').empty();
       points.forEach(p => $ul.append(p));
-      var fail = !!points.length;
+      const fail = !!points.length;
       $overview.toggleClass('with-todo', fail);
       if (fail) $listed.prop('checked', false);
       $listed.prop('disabled', fail);

ui/site/src/coordinate.ts

@@ -3,24 +3,24 @@ import sparkline from '@fnando/sparkline';
 
 lichess.load.then(() => {
   $('#trainer').each(function (this: HTMLElement) {
-    var $trainer = $(this);
+    const $trainer = $(this);
-    var $board = $('.coord-trainer__board .cg-wrap');
+    const $board = $('.coord-trainer__board .cg-wrap');
-    var ground;
+    let ground;
-    var $side = $('.coord-trainer__side');
+    const $side = $('.coord-trainer__side');
-    var $right = $('.coord-trainer__table');
+    const $right = $('.coord-trainer__table');
-    var $bar = $trainer.find('.progress_bar');
+    const $bar = $trainer.find('.progress_bar');
-    var $coords = [$('#next_coord0'), $('#next_coord1'), $('#next_coord2')];
+    const $coords = [$('#next_coord0'), $('#next_coord1'), $('#next_coord2')];
-    var $start = $right.find('.start');
+    const $start = $right.find('.start');
-    var $explanation = $right.find('.explanation');
+    const $explanation = $right.find('.explanation');
-    var $score = $('.coord-trainer__score');
+    const $score = $('.coord-trainer__score');
-    var scoreUrl = $trainer.data('score-url');
+    const scoreUrl = $trainer.data('score-url');
-    var duration = 30 * 1000;
+    const duration = 30 * 1000;
-    var tickDelay = 50;
+    const tickDelay = 50;
-    var colorPref = $trainer.data('color-pref');
+    let colorPref = $trainer.data('color-pref');
-    var color;
+    let color;
-    var startAt, score;
+    let startAt, score;
 
-    var showColor = function () {
+    const showColor = function () {
       color = colorPref == 'random' ? ['white', 'black'][Math.round(Math.random())] : colorPref;
       if (!ground)
         ground = window.Chessground($board[0], {
@@ -42,8 +42,8 @@ lichess.load.then(() => {
       const form = this,
         $form = $(this);
       $form.find('input').on('change', function () {
-        var selected = $form.find('input:checked').val() as string;
+        const selected = $form.find('input:checked').val() as string;
-        var c = {
+        const c = {
           1: 'white',
           2: 'random',
           3: 'black',
@@ -85,25 +85,25 @@ lichess.load.then(() => {
     }
     requestAnimationFrame(showCharts);
 
-    var centerRight = function () {
+    const centerRight = function () {
       $right.css('top', 256 - $right.height() / 2 + 'px');
     };
     centerRight();
 
-    var clearCoords = function () {
+    const clearCoords = function () {
       $.each($coords, function (_, e) {
         e.text('');
       });
     };
 
-    var newCoord = function (prevCoord) {
+    const newCoord = function (prevCoord) {
       // disallow the previous coordinate's row or file from being selected
-      var files = 'abcdefgh';
+      let files = 'abcdefgh';
-      var fileIndex = files.indexOf(prevCoord[0]);
+      const fileIndex = files.indexOf(prevCoord[0]);
       files = files.slice(0, fileIndex) + files.slice(fileIndex + 1, 8);
 
-      var rows = '12345678';
+      let rows = '12345678';
-      var rowIndex = rows.indexOf(prevCoord[1]);
+      const rowIndex = rows.indexOf(prevCoord[1]);
       rows = rows.slice(0, rowIndex) + rows.slice(rowIndex + 1, 8);
 
       return (
@@ -111,9 +111,9 @@ lichess.load.then(() => {
       );
     };
 
-    var advanceCoords = function () {
+    const advanceCoords = function () {
       $('#next_coord0').removeClass('nope');
-      var lastElement = $coords.shift()!;
+      const lastElement = $coords.shift()!;
       $.each($coords, function (i, e) {
         e.attr('id', 'next_coord' + i);
       });
@@ -122,7 +122,7 @@ lichess.load.then(() => {
       $coords.push(lastElement);
     };
 
-    var stop = function () {
+    const stop = function () {
       clearCoords();
       $trainer.removeClass('play');
       centerRight();
@@ -145,7 +145,7 @@ lichess.load.then(() => {
     };
 
     var tick = function () {
-      var spent = Math.min(duration, new Date().getTime() - startAt);
+      const spent = Math.min(duration, new Date().getTime() - startAt);
       $bar.css('width', (100 * spent) / duration + '%');
       if (spent < duration) setTimeout(tick, tickDelay);
       else stop();
@@ -165,7 +165,7 @@ lichess.load.then(() => {
         ground.set({
           events: {
             select(key) {
-              var hit = key == $coords[0].text();
+              const hit = key == $coords[0].text();
               if (hit) {
                 score++;
                 $score.text(score);
@@ -181,7 +181,7 @@ lichess.load.then(() => {
           },
         });
         $coords[0].text(newCoord('a1'));
-        var i;
+        let i;
         for (i = 1; i < $coords.length; i++) $coords[i].text(newCoord($coords[i - 1].text()));
         tick();
       }, 1000);

ui/site/src/expandText.ts

@@ -60,7 +60,7 @@ lichess.load.then(() => {
       };
     matches = a.href.match(gameRegex);
     if (matches && matches[1] && !notGames.includes(matches[1]) && a.text.match(gameRegex)) {
-      var src = '/embed/' + matches[1];
+      let src = '/embed/' + matches[1];
       if (matches[2]) src += '/' + matches[2]; // orientation
       if (matches[3]) src += matches[3]; // ply hash
       return {
@@ -71,7 +71,7 @@ lichess.load.then(() => {
   }
 
   function expandYoutube(a: Candidate) {
-    var $iframe = $('<div class="embed"><iframe src="' + a.src + '"></iframe></div>');
+    const $iframe = $('<div class="embed"><iframe src="' + a.src + '"></iframe></div>');
     $(a.element).replaceWith($iframe);
     return $iframe;
   }

ui/site/src/forum.ts

@@ -53,7 +53,7 @@ lichess.load.then(() => {
                 // Initially we only autocomplete by participants in the thread. As the user types more,
                 // we can autocomplete against all users on the site.
                 threadParticipants.then(function (participants) {
-                  var forumParticipantCandidates = searchCandidates(term, participants);
+                  const forumParticipantCandidates = searchCandidates(term, participants);
 
                   if (forumParticipantCandidates.length != 0) {
                     // We always prefer a match on the forum thread partcipants' usernames

ui/site/src/gameSearch.ts

@@ -15,9 +15,9 @@ lichess.load.then(() => {
   }
 
   function userChoices(row) {
-    var options = ["<option value=''></option>"];
+    const options = ["<option value=''></option>"];
-    var isSelected = function (row, rowClassName, user, dataKey) {
+    const isSelected = function (row, rowClassName, user, dataKey) {
-      var player = $form.data(dataKey);
+      const player = $form.data(dataKey);
       return row.classList.contains(rowClassName) && player.length && user == player ? 'selected' : '';
     };
     getUsernames().forEach(function (user) {
@@ -42,7 +42,7 @@ lichess.load.then(() => {
   reloadUserChoices();
   $usernames.on('input paste', reloadUserChoices);
 
-  var toggleAiLevel = function () {
+  const toggleAiLevel = function () {
     $form.find('.opponent select').each(function (this: HTMLSelectElement) {
       $form.find('.aiLevel').toggleClass('none', this.value != '1');
       $form.find('.opponentName').toggleClass('none', this.value == '1');

ui/site/src/passwordComplexity.ts

@@ -21,7 +21,7 @@ function updateMeter(score: number): void {
   const meter = document.querySelector('.password-complexity-meter');
   const children = meter?.children || [];
 
-  for (var i = 0; i < children.length; i++) {
+  for (let i = 0; i < children.length; i++) {
     (children[i] as HTMLElement).style.backgroundColor = i < score ? color : '';
   }
 }

ui/tournamentSchedule/src/view.ts

@@ -79,7 +79,7 @@ function splitOverlaping(lanes) {
   let ret: any[] = [],
     i: number;
   lanes.forEach(lane => {
-    var newLanes: any[] = [[]];
+    const newLanes: any[] = [[]];
     lane.forEach(tour => {
       let collision = true;
       for (i = 0; i < newLanes.length; i++) {

ui/tree/src/tree.ts

@@ -60,13 +60,13 @@ export function build(root: Tree.Node): TreeWrapper {
   }
 
   function longestValidPathFrom(node: Tree.Node, path: Tree.Path): Tree.Path {
-    var id = treePath.head(path);
+    const id = treePath.head(path);
     const child = ops.childById(node, id);
     return child ? id + longestValidPathFrom(child, treePath.tail(path)) : '';
   }
 
   function getCurrentNodesAfterPly(nodeList: Tree.Node[], mainline: Tree.Node[], ply: number): Tree.Node[] {
-    var node,
+    let node,
       nodes = [];
     for (const i in nodeList) {
       node = nodeList[i];
@@ -151,10 +151,10 @@ export function build(root: Tree.Node): TreeWrapper {
   }
 
   function promoteAt(path: Tree.Path, toMainline: boolean): void {
-    var nodes = getNodeList(path);
+    const nodes = getNodeList(path);
-    for (var i = nodes.length - 2; i >= 0; i--) {
+    for (let i = nodes.length - 2; i >= 0; i--) {
-      var node = nodes[i + 1];
+      const node = nodes[i + 1];
-      var parent = nodes[i];
+      const parent = nodes[i];
       if (parent.children[0].id !== node.id) {
         ops.removeChild(parent, node.id);
         parent.children.unshift(node);
@@ -181,7 +181,7 @@ export function build(root: Tree.Node): TreeWrapper {
 
   function deleteCommentAt(id: string, path: Tree.Path) {
     return updateAt(path, function (node) {
-      var comments = (node.comments || []).filter(function (c) {
+      const comments = (node.comments || []).filter(function (c) {
         return c.id !== id;
       });
       node.comments = comments.length ? comments : undefined;