Use fat arrow functions const foo = () => { ... }; for callbacks

and any other function that is passed around and it's not a top level function
shepner · Jul 12, 2018 · 651c23e · 651c23e
1 parent 0e4808b
commit 651c23e
Show file tree

Hide file tree

Showing 28 changed files with 178 additions and 192 deletions.
diff --git a/.eslintrc b/.eslintrc
@@ -13,5 +13,10 @@
         "no-var": "error",
         "no-useless-constructor": "error",
         "object-shorthand": ["error", "methods", { "avoidQuotes": true }],
+        "prefer-arrow-callback": "error",
+        "arrow-body-style": ["error", "as-needed", { "requireReturnForObjectLiteral": false } ],
+        "arrow-parens": ["error", "as-needed", { "requireForBlockBody": true }],
+        "arrow-spacing": ["error"],
+        "no-confusing-arrow": ["error", { "allowParens": true }],
     }
 }
diff --git a/app/error-handler.js b/app/error-handler.js
@@ -2,7 +2,10 @@
 // native support in the browsers, so that our error handler
 // can catch script-loading errors.
 
-(function(){
+// No ES6 can be used in this file since it's used for the translation
+/* eslint-disable prefer-arrow-callback */
+
+(function() {
     "use strict";
 
     // Fallback for all uncought errors

diff --git a/app/ui.js b/app/ui.js
@@ -71,7 +71,7 @@ const UI = {
         if (isTouchDevice) {
             document.documentElement.classList.add("noVNC_touch");
             // Remove the address bar
-            setTimeout(function() { window.scrollTo(0, 1); }, 100);
+            setTimeout(() => window.scrollTo(0, 1), 100);
         }
 
         // Restore control bar position
@@ -230,13 +230,13 @@ const UI = {
 
     addTouchSpecificHandlers() {
         document.getElementById("noVNC_mouse_button0")
-            .addEventListener('click', function () { UI.setMouseButton(1); });
+            .addEventListener('click', () => UI.setMouseButton(1));
         document.getElementById("noVNC_mouse_button1")
-            .addEventListener('click', function () { UI.setMouseButton(2); });
+            .addEventListener('click', () => UI.setMouseButton(2));
         document.getElementById("noVNC_mouse_button2")
-            .addEventListener('click', function () { UI.setMouseButton(4); });
+            .addEventListener('click', () => UI.setMouseButton(4));
         document.getElementById("noVNC_mouse_button4")
-            .addEventListener('click', function () { UI.setMouseButton(0); });
+            .addEventListener('click', () => UI.setMouseButton(0));
         document.getElementById("noVNC_keyboard_button")
             .addEventListener('click', UI.toggleVirtualKeyboard);
 
@@ -250,7 +250,7 @@ const UI = {
         document.getElementById("noVNC_keyboardinput")
             .addEventListener('blur', UI.onblurVirtualKeyboard);
         document.getElementById("noVNC_keyboardinput")
-            .addEventListener('submit', function () { return false; });
+            .addEventListener('submit', () => false);
 
         document.documentElement
             .addEventListener('mousedown', UI.keepVirtualKeyboard, true);
@@ -294,11 +294,11 @@ const UI = {
 
     addMachineHandlers() {
         document.getElementById("noVNC_shutdown_button")
-            .addEventListener('click', function() { UI.rfb.machineShutdown(); });
+            .addEventListener('click', () => UI.rfb.machineShutdown());
         document.getElementById("noVNC_reboot_button")
-            .addEventListener('click', function() { UI.rfb.machineReboot(); });
+            .addEventListener('click', () => UI.rfb.machineReboot());
         document.getElementById("noVNC_reset_button")
-            .addEventListener('click', function() { UI.rfb.machineReset(); });
+            .addEventListener('click', () => UI.rfb.machineReset());
         document.getElementById("noVNC_power_button")
             .addEventListener('click', UI.togglePowerPanel);
     },
@@ -329,7 +329,7 @@ const UI = {
     addSettingChangeHandler(name, changeFunc) {
         const settingElem = document.getElementById("noVNC_setting_" + name);
         if (changeFunc === undefined) {
-            changeFunc = function () { UI.saveSetting(name); };
+            changeFunc = () => UI.saveSetting(name);
         }
         settingElem.addEventListener('change', changeFunc);
     },
@@ -552,8 +552,7 @@ const UI = {
         const barDisplayStyle = window.getComputedStyle(bar).display;
         if (barDisplayStyle !== 'none') {
             bar.style.transitionDuration = '0s';
-            bar.addEventListener('transitionend', function () {
-                this.style.transitionDuration = ""; });
+            bar.addEventListener('transitionend', () => bar.style.transitionDuration = '');
         }
 
         const anchor = document.getElementById('noVNC_control_bar_anchor');
@@ -1029,7 +1028,7 @@ const UI = {
         UI.rfb.addEventListener("disconnect", UI.disconnectFinished);
         UI.rfb.addEventListener("credentialsrequired", UI.credentials);
         UI.rfb.addEventListener("securityfailure", UI.securityFailed);
-        UI.rfb.addEventListener("capabilities", function () { UI.updatePowerButton(); });
+        UI.rfb.addEventListener("capabilities", UI.updatePowerButton);
         UI.rfb.addEventListener("clipboard", UI.clipboardReceive);
         UI.rfb.addEventListener("bell", UI.bell);
         UI.rfb.addEventListener("desktopname", UI.updateDesktopName);
@@ -1153,9 +1152,8 @@ const UI = {
         document.getElementById('noVNC_password_dlg')
             .classList.add('noVNC_open');
 
-        setTimeout(function () {
-                document.getElementById('noVNC_password_input').focus();
-            }, 100);
+        setTimeout(() => document
+            .getElementById('noVNC_password_input').focus(), 100);
 
         Log.Warn("Server asked for a password");
         UI.showStatus(_("Password is required"), "warning");
@@ -1624,7 +1622,7 @@ const UI = {
             const promise = document.getElementById('noVNC_bell').play();
             // The standards disagree on the return value here
             if (promise) {
-                promise.catch(function(e) {
+                promise.catch((e) => {
                     if (e.name === "NotAllowedError") {
                         // Ignore when the browser doesn't let us play audio.
                         // It is common that the browsers require audio to be
@@ -1655,12 +1653,12 @@ const UI = {
 const LINGUAS = ["de", "el", "es", "nl", "pl", "sv", "tr", "zh_CN", "zh_TW"];
 l10n.setup(LINGUAS);
 if (l10n.language !== "en" && l10n.dictionary === undefined) {
-    WebUtil.fetchJSON('app/locale/' + l10n.language + '.json', function (translations) {
+    WebUtil.fetchJSON('app/locale/' + l10n.language + '.json', (translations) => {
         l10n.dictionary = translations;
 
         // wait for translations to load before loading the UI
         UI.prime();
-    }, function (err) {
+    }, (err) => {
         Log.Error("Failed to load translations: " + err);
         UI.prime();
     });

diff --git a/app/webutil.js b/app/webutil.js
@@ -119,7 +119,7 @@ export function initSettings (callback /*, ...callbackArgs */) {
     "use strict";
     const callbackArgs = Array.prototype.slice.call(arguments, 1);
     if (window.chrome && window.chrome.storage) {
-        window.chrome.storage.sync.get(function (cfg) {
+        window.chrome.storage.sync.get((cfg) => {
             settings = cfg;
             if (callback) {
                 callback.apply(this, callbackArgs);
@@ -201,7 +201,7 @@ export function injectParamIfMissing (path, param, value) {
         query = [];
     }
 
-    if (!query.some(function (v) { return v.startsWith(param_eq); })) {
+    if (!query.some(v => v.startsWith(param_eq))) {
         query.push(param_eq + encodeURIComponent(value));
         elem.search = "?" + query.join("&");
     }
@@ -224,7 +224,7 @@ export function fetchJSON(path, resolve, reject) {
     const req = new XMLHttpRequest();
     req.open('GET', path);
 
-    req.onload = function () {
+    req.onload = () => {
         if (req.status === 200) {
             let resObj;
             try {
@@ -238,13 +238,9 @@ export function fetchJSON(path, resolve, reject) {
         }
     };
 
-    req.onerror = function (evt) {
-        reject(new Error("XHR encountered an error while trying to load '" + path + "': " + evt.message));
-    };
+    req.onerror = evt => reject(new Error("XHR encountered an error while trying to load '" + path + "': " + evt.message));
 
-    req.ontimeout = function (evt) {
-        reject(new Error("XHR timed out while trying to load '" + path + "'"));
-    };
+    req.ontimeout = evt => reject(new Error("XHR timed out while trying to load '" + path + "'"));
 
     req.send();
 }
diff --git a/core/input/keyboard.js b/core/input/keyboard.js
@@ -307,7 +307,7 @@ export default class Keyboard {
 
         const target = this._target;
         const downList = this._keyDownList;
-        ['AltLeft', 'AltRight'].forEach(function (code) {
+        ['AltLeft', 'AltRight'].forEach((code) => {
             if (!(code in downList)) {
                 return;
             }
@@ -338,11 +338,10 @@ export default class Keyboard {
             const handler = this._eventHandlers.checkalt;
             ['mousedown', 'mouseup', 'mousemove', 'wheel',
              'touchstart', 'touchend', 'touchmove',
-             'keydown', 'keyup'].forEach(function (type) {
+             'keydown', 'keyup'].forEach(type =>
                 document.addEventListener(type, handler,
                                           { capture: true,
-                                            passive: true });
-             });
+                                            passive: true }));
         }
 
         //Log.Debug("<< Keyboard.grab");
@@ -355,9 +354,7 @@ export default class Keyboard {
             const handler = this._eventHandlers.checkalt;
             ['mousedown', 'mouseup', 'mousemove', 'wheel',
              'touchstart', 'touchend', 'touchmove',
-             'keydown', 'keyup'].forEach(function (type) {
-                document.removeEventListener(type, handler);
-            });
+             'keydown', 'keyup'].forEach(type => document.removeEventListener(type, handler));
         }
 
         this._target.removeEventListener('keydown', this._eventHandlers.keydown);

diff --git a/core/rfb.js b/core/rfb.js
@@ -201,17 +201,17 @@ export default class RFB extends EventTargetMixin {
 
         this._sock = new Websock();
         this._sock.on('message', this._handle_message.bind(this));
-        this._sock.on('open', function () {
+        this._sock.on('open', () => {
             if ((this._rfb_connection_state === 'connecting') &&
                 (this._rfb_init_state === '')) {
                 this._rfb_init_state = 'ProtocolVersion';
                 Log.Debug("Starting VNC handshake");
             } else {
                 this._fail("Unexpected server connection while " +
-                        this._rfb_connection_state);
+                           this._rfb_connection_state);
             }
-        }.bind(this));
-        this._sock.on('close', function (e) {
+        });
+        this._sock.on('close', (e) => {
             Log.Debug("WebSocket on-close event");
             let msg = "";
             if (e.code) {
@@ -236,18 +236,16 @@ export default class RFB extends EventTargetMixin {
                     break;
                 case 'disconnected':
                     this._fail("Unexpected server disconnect " +
-                            "when already disconnected " + msg);
+                               "when already disconnected " + msg);
                     break;
                 default:
                     this._fail("Unexpected server disconnect before connecting " +
-                            msg);
+                               msg);
                     break;
             }
             this._sock.off('close');
-        }.bind(this));
-        this._sock.on('error', function (e) {
-            Log.Warn("WebSocket on-error event");
         });
+        this._sock.on('error', e => Log.Warn("WebSocket on-error event"));
 
         // Slight delay of the actual connection so that the caller has
         // time to set up callbacks
@@ -459,18 +457,15 @@ export default class RFB extends EventTargetMixin {
         const stats = this._encStats;
 
         Log.Info("Encoding stats for this connection:");
-        Object.keys(stats).forEach(function (key) {
+        Object.keys(stats).forEach((key) => {
             const s = stats[key];
             if (s[0] + s[1] > 0) {
                 Log.Info("    " + encodingName(key) + ": " + s[0] + " rects");
             }
         });
 
         Log.Info("Encoding stats since page load:");
-        Object.keys(stats).forEach(function (key) {
-            const s = stats[key];
-            Log.Info("    " + encodingName(key) + ": " + s[1] + " rects");
-        });
+        Object.keys(stats).forEach(key => Log.Info("    " + encodingName(key) + ": " + stats[key][1] + " rects"));
     }
 
     _focusCanvas(event) {
@@ -489,10 +484,10 @@ export default class RFB extends EventTargetMixin {
     _windowResize(event) {
         // If the window resized then our screen element might have
         // as well. Update the viewport dimensions.
-        window.requestAnimationFrame(function () {
+        window.requestAnimationFrame(() => {
             this._updateClip();
             this._updateScale();
-        }.bind(this));
+        });
 
         if (this._resizeSession) {
             // Request changing the resolution of the remote display to
@@ -640,8 +635,7 @@ export default class RFB extends EventTargetMixin {
 
         this._rfb_connection_state = state;
 
-        const smsg = "New state '" + state + "', was '" + oldstate + "'.";
-        Log.Debug(smsg);
+        Log.Debug("New state '" + state + "', was '" + oldstate + "'.");
 
         if (this._disconnTimer && state !== 'disconnecting') {
             Log.Debug("Clearing disconnect timer");
@@ -664,10 +658,10 @@ export default class RFB extends EventTargetMixin {
             case 'disconnecting':
                 this._disconnect();
 
-                this._disconnTimer = setTimeout(function () {
+                this._disconnTimer = setTimeout(() => {
                     Log.Error("Disconnection timed out.");
                     this._updateConnectionState('disconnected');
-                }.bind(this), DISCONNECT_TIMEOUT * 1000);
+                }, DISCONNECT_TIMEOUT * 1000);
                 break;
 
             case 'disconnected':
@@ -2143,7 +2137,7 @@ RFB.encodingHandlers = {
 
         let resetStreams = 0;
         let streamId = -1;
-        const decompress = function (data, expected) {
+        const decompress = (data, expected) => {
             for (let i = 0; i < 4; i++) {
                 if ((resetStreams >> i) & 1) {
                     this._FBU.zlibs[i].reset();
@@ -2159,9 +2153,9 @@ RFB.encodingHandlers = {
 
             //return uncompressed.data;
             return uncompressed;
-        }.bind(this);
+        };
 
-        const indexedToRGBX2Color = function (data, palette, width, height) {
+        const indexedToRGBX2Color = (data, palette, width, height) => {
             // Convert indexed (palette based) image data to RGB
             // TODO: reduce number of calculations inside loop
             const dest = this._destBuff;
@@ -2220,9 +2214,9 @@ RFB.encodingHandlers = {
             }
 
             return dest;
-        }.bind(this);
+        };
 
-        const indexedToRGBX = function (data, palette, width, height) {
+        const indexedToRGBX = (data, palette, width, height) => {
             // Convert indexed (palette based) image data to RGB
             const dest = this._destBuff;
             const total = width * height * 4;
@@ -2235,14 +2229,14 @@ RFB.encodingHandlers = {
             }
 
             return dest;
-        }.bind(this);
+        };
 
         const rQi = this._sock.get_rQi();
         const rQ = this._sock.rQwhole();
         let cmode, data;
         let cl_header, cl_data;
 
-        const handlePalette = function () {
+        const handlePalette = () => {
             const numColors = rQ[rQi + 2] + 1;
             const paletteSize = numColors * 3;
             this._FBU.bytes += paletteSize;
@@ -2300,9 +2294,9 @@ RFB.encodingHandlers = {
 
 
             return true;
-        }.bind(this);
+        };
 
-        const handleCopy = function () {
+        const handleCopy = () => {
             let raw = false;
             const uncompressedSize = this._FBU.width * this._FBU.height * 3;
             if (uncompressedSize < 12) {
@@ -2340,7 +2334,7 @@ RFB.encodingHandlers = {
             this._display.blitRgbImage(this._FBU.x, this._FBU.y, this._FBU.width, this._FBU.height, data, 0, false);
 
             return true;
-        }.bind(this);
+        };
 
         let ctl = this._sock.rQpeek8();
 

diff --git a/core/util/events.js b/core/util/events.js
@@ -120,7 +120,7 @@ export function releaseCapture () {
 
         // There might be events already queued, so we need to wait for
         // them to flush. E.g. contextmenu in Microsoft Edge
-        window.setTimeout(function(expected) {
+        window.setTimeout((expected) => {
             // Only clear it if it's the expected grab (i.e. no one
             // else has initiated a new grab)
             if (_captureIndex === expected) {