chore: eslint prefer-arrow-callback

.eslintrc

@@ -110,7 +110,6 @@
 		// WORKING ON
 		"prefer-rest-params": "off",
 		"prefer-spread": "off",
-		"prefer-arrow-callback": "off",
 		"no-var": "off",
 		"vars-on-top": "off",
 

Gruntfile.js

@@ -164,7 +164,7 @@ module.exports = function (grunt) {
 	grunt.task.run('init');
 
 	grunt.event.removeAllListeners('watch');
-	grunt.event.on('watch', function update(action, filepath, target) {
+	grunt.event.on('watch', (action, filepath, target) => {
 		var compiling;
 		if (target === 'styleUpdated_Client') {
 			compiling = 'clientCSS';
@@ -183,7 +183,7 @@ module.exports = function (grunt) {
 			return run();
 		}
 
-		require('./src/meta/build').build([compiling], function (err) {
+		require('./src/meta/build').build([compiling], (err) => {
 			if (err) {
 				winston.error(err.stack);
 			}

install/web.js

@@ -72,7 +72,7 @@ web.install = async function (port) {
 	winston.info(`Launching web installer on port ${port}`);
 
 	app.use(express.static('public', {}));
-	app.engine('tpl', function (filepath, options, callback) {
+	app.engine('tpl', (filepath, options, callback) => {
 		filepath = filepath.replace(/\.tpl$/, '.js');
 
 		Benchpress.__express(filepath, options, callback);
@@ -99,7 +99,7 @@ web.install = async function (port) {
 
 
 function launchExpress(port) {
-	server = app.listen(port, function () {
+	server = app.listen(port, () => {
 		winston.info('Web installer listening on http://%s:%s', '0.0.0.0', port);
 	});
 }
@@ -118,10 +118,8 @@ function ping(req, res) {
 
 function welcome(req, res) {
 	var dbs = ['redis', 'mongo', 'postgres'];
-	var databases = dbs.map(function (databaseName) {
-		var questions = require(`../src/database/${databaseName}`).questions.filter(function (question) {
-			return question && !question.hideOnWebInstall;
-		});
+	var databases = dbs.map((databaseName) => {
+		var questions = require(`../src/database/${databaseName}`).questions.filter(question => question && !question.hideOnWebInstall);
 
 		return {
 			name: databaseName,
@@ -180,7 +178,7 @@ function install(req, res) {
 		env: setupEnvVars,
 	});
 
-	child.on('close', function (data) {
+	child.on('close', (data) => {
 		installing = false;
 		success = data === 0;
 		error = data !== 0;

loader.js

@@ -60,14 +60,14 @@ Loader.displayStartupMessages = function (callback) {
 };
 
 Loader.addWorkerEvents = function (worker) {
-	worker.on('exit', function (code, signal) {
+	worker.on('exit', (code, signal) => {
 		if (code !== 0) {
 			if (Loader.timesStarted < numProcs * 3) {
 				Loader.timesStarted += 1;
 				if (Loader.crashTimer) {
 					clearTimeout(Loader.crashTimer);
 				}
-				Loader.crashTimer = setTimeout(function () {
+				Loader.crashTimer = setTimeout(() => {
 					Loader.timesStarted = 0;
 				}, 10000);
 			} else {
@@ -84,20 +84,20 @@ Loader.addWorkerEvents = function (worker) {
 		}
 	});
 
-	worker.on('message', function (message) {
+	worker.on('message', (message) => {
 		if (message && typeof message === 'object' && message.action) {
 			switch (message.action) {
 				case 'restart':
 					console.log('[cluster] Restarting...');
 					Loader.restart();
 					break;
 				case 'pubsub':
-					workers.forEach(function (w) {
+					workers.forEach((w) => {
 						w.send(message);
 					});
 					break;
 				case 'socket.io':
-					workers.forEach(function (w) {
+					workers.forEach((w) => {
 						if (w !== worker) {
 							w.send(message);
 						}
@@ -172,7 +172,7 @@ Loader.restart = function () {
 	nconf.remove('file');
 	nconf.use('file', { file: pathToConfig });
 
-	fs.readFile(pathToConfig, { encoding: 'utf-8' }, function (err, configFile) {
+	fs.readFile(pathToConfig, { encoding: 'utf-8' }, (err, configFile) => {
 		if (err) {
 			console.error('Error reading config');
 			throw err;
@@ -201,13 +201,13 @@ Loader.stop = function () {
 };
 
 function killWorkers() {
-	workers.forEach(function (worker) {
+	workers.forEach((worker) => {
 		worker.suicide = true;
 		worker.kill();
 	});
 }
 
-fs.open(pathToConfig, 'r', function (err) {
+fs.open(pathToConfig, 'r', (err) => {
 	if (err) {
 		// No config detected, kickstart web installer
 		fork('app');
@@ -238,7 +238,7 @@ fs.open(pathToConfig, 'r', function (err) {
 		Loader.init,
 		Loader.displayStartupMessages,
 		Loader.start,
-	], function (err) {
+	], (err) => {
 		if (err) {
 			console.error('[loader] Error during startup');
 			throw err;

src/admin/search.js

@@ -10,20 +10,22 @@ const file = require('../file');
 const Translator = require('../translator').Translator;
 
 function filterDirectories(directories) {
-	return directories.map(function (dir) {
+	return directories.map(
 		// get the relative path
 		// convert dir to use forward slashes
-		return dir.replace(/^.*(admin.*?).tpl$/, '$1').split(path.sep).join('/');
-	}).filter(function (dir) {
+		dir => dir.replace(/^.*(admin.*?).tpl$/, '$1').split(path.sep).join('/')
+	).filter(
 		// exclude .js files
 		// exclude partials
 		// only include subpaths
 		// exclude category.tpl, group.tpl, category-analytics.tpl
-		return !dir.endsWith('.js') &&
+		dir => (
+			!dir.endsWith('.js') &&
 			!dir.includes('/partials/') &&
 			/\/.*\//.test(dir) &&
-			!/manage\/(category|group|category-analytics)$/.test(dir);
-	});
+			!/manage\/(category|group|category-analytics)$/.test(dir)
+		)
+	);
 }
 
 async function getAdminNamespaces() {
@@ -50,9 +52,7 @@ function simplify(translations) {
 }
 
 function nsToTitle(namespace) {
-	return namespace.replace('admin/', '').split('/').map(function (str) {
-		return str[0].toUpperCase() + str.slice(1);
-	}).join(' > ')
+	return namespace.replace('admin/', '').split('/').map(str => str[0].toUpperCase() + str.slice(1)).join(' > ')
 		.replace(/[^a-zA-Z> ]/g, ' ');
 }
 
@@ -97,9 +97,7 @@ async function buildNamespace(language, namespace) {
 			return await fallback(namespace);
 		}
 		// join all translations into one string separated by newlines
-		let str = Object.keys(translations).map(function (key) {
-			return translations[key];
-		}).join('\n');
+		let str = Object.keys(translations).map(key => translations[key]).join('\n');
 		str = sanitize(str);
 
 		let title = namespace;

src/admin/versions.js

@@ -23,7 +23,7 @@ function getLatestVersion(callback) {
 		json: true,
 		headers: headers,
 		timeout: 2000,
-	}, function (err, res, latestRelease) {
+	}, (err, res, latestRelease) => {
 		if (err) {
 			return callback(err);
 		}

src/analytics.js

@@ -33,17 +33,17 @@ Analytics.init = async function () {
 		maxAge: 0,
 	});
 
-	new cronJob('*/10 * * * * *', function () {
+	new cronJob('*/10 * * * * *', (() => {
 		Analytics.writeData();
-	}, null, true);
+	}), null, true);
 };
 
 Analytics.increment = function (keys, callback) {
 	keys = Array.isArray(keys) ? keys : [keys];
 
 	plugins.hooks.fire('action:analytics.increment', { keys: keys });
 
-	keys.forEach(function (key) {
+	keys.forEach((key) => {
 		counters[key] = counters[key] || 0;
 		counters[key] += 1;
 	});
@@ -163,14 +163,14 @@ Analytics.getHourlyStatsForSet = async function (set, hour, numHours) {
 
 	const counts = await db.sortedSetScores(set, hoursArr);
 
-	hoursArr.forEach(function (term, index) {
+	hoursArr.forEach((term, index) => {
 		terms[term] = parseInt(counts[index], 10) || 0;
 	});
 
 	const termsArr = [];
 
 	hoursArr.reverse();
-	hoursArr.forEach(function (hour) {
+	hoursArr.forEach((hour) => {
 		termsArr.push(terms[hour]);
 	});
 

src/api/helpers.js

@@ -54,7 +54,7 @@ exports.doTopicAction = async function (action, event, caller, { tids }) {
 
 	const uids = await user.getUidsFromSet('users:online', 0, -1);
 
-	await Promise.all(tids.map(async function (tid) {
+	await Promise.all(tids.map(async (tid) => {
 		const title = await topics.getTopicField(tid, 'title');
 		const data = await topics.tools[action](tid, caller.uid);
 		const notifyUids = await privileges.categories.filterUids('topics:read', data.cid, uids);

src/cacheCreate.js

@@ -55,11 +55,11 @@ module.exports = function (opts) {
 		cache.misses = 0;
 	}
 
-	pubsub.on(`${cache.name}:cache:reset`, function () {
+	pubsub.on(`${cache.name}:cache:reset`, () => {
 		localReset();
 	});
 
-	pubsub.on(`${cache.name}:cache:del`, function (keys) {
+	pubsub.on(`${cache.name}:cache:del`, (keys) => {
 		if (Array.isArray(keys)) {
 			keys.forEach(key => cacheDel.apply(cache, [key]));
 		}
@@ -71,7 +71,7 @@ module.exports = function (opts) {
 		}
 		let data;
 		let isCached;
-		const unCachedKeys = keys.filter(function (key) {
+		const unCachedKeys = keys.filter((key) => {
 			data = cache.get(key);
 			isCached = data !== undefined;
 			if (isCached) {

src/categories/create.js

@@ -104,7 +104,7 @@ module.exports = function (Categories) {
 
 		children = children[0];
 
-		children.forEach(function (child) {
+		children.forEach((child) => {
 			child.parentCid = parentCid;
 			child.cloneFromCid = child.cid;
 			child.cloneChildren = true;
@@ -195,7 +195,7 @@ module.exports = function (Categories) {
 
 		const currentMembers = await db.getSortedSetsMembers(toGroups.concat(fromGroups));
 		const copyGroups = _.uniq(_.flatten(currentMembers));
-		await async.each(copyGroups, async function (group) {
+		await async.each(copyGroups, async (group) => {
 			await copyPrivilegesByGroup(privileges, fromCid, toCid, group);
 		});
 	}

src/categories/delete.js

@@ -11,14 +11,14 @@ var cache = require('../cache');
 
 module.exports = function (Categories) {
 	Categories.purge = async function (cid, uid) {
-		await batch.processSortedSet(`cid:${cid}:tids`, async function (tids) {
-			await async.eachLimit(tids, 10, async function (tid) {
+		await batch.processSortedSet(`cid:${cid}:tids`, async (tids) => {
+			await async.eachLimit(tids, 10, async (tid) => {
 				await topics.purgePostsAndTopic(tid, uid);
 			});
 		}, { alwaysStartAt: 0 });
 
 		const pinnedTids = await db.getSortedSetRevRange(`cid:${cid}:tids:pinned`, 0, -1);
-		await async.eachLimit(pinnedTids, 10, async function (tid) {
+		await async.eachLimit(pinnedTids, 10, async (tid) => {
 			await topics.purgePostsAndTopic(tid, uid);
 		});
 		const categoryData = await Categories.getCategoryData(cid);
@@ -58,7 +58,7 @@ module.exports = function (Categories) {
 		]);
 
 		const bulkAdd = [];
-		const childrenKeys = children.map(function (cid) {
+		const childrenKeys = children.map((cid) => {
 			bulkAdd.push(['cid:0:children', cid, cid]);
 			return `category:${cid}`;
 		});

src/categories/index.js

@@ -97,15 +97,15 @@ Categories.getModerators = async function (cid) {
 };
 
 Categories.getModeratorUids = async function (cids) {
-	const groupNames = cids.reduce(function (memo, cid) {
+	const groupNames = cids.reduce((memo, cid) => {
 		memo.push(`cid:${cid}:privileges:moderate`);
 		memo.push(`cid:${cid}:privileges:groups:moderate`);
 		return memo;
 	}, []);
 
 	const memberSets = await groups.getMembersOfGroups(groupNames);
 	// Every other set is actually a list of user groups, not uids, so convert those to members
-	const sets = memberSets.reduce(function (memo, set, idx) {
+	const sets = memberSets.reduce((memo, set, idx) => {
 		if (idx % 2) {
 			memo.groupNames.push(set);
 		} else {
@@ -137,7 +137,7 @@ Categories.getCategories = async function (cids, uid) {
 		Categories.getTagWhitelist(cids),
 		Categories.hasReadCategories(cids, uid),
 	]);
-	categories.forEach(function (category, i) {
+	categories.forEach((category, i) => {
 		if (category) {
 			category.tagWhitelist = tagWhitelist[i];
 			category['unread-class'] = (category.topic_count === 0 || (hasRead[i] && uid !== 0)) ? '' : 'unread';
@@ -180,7 +180,7 @@ function calculateTopicPostCount(category) {
 	let postCount = category.post_count;
 	let topicCount = category.topic_count;
 	if (Array.isArray(category.children)) {
-		category.children.forEach(function (child) {
+		category.children.forEach((child) => {
 			calculateTopicPostCount(child);
 			postCount += parseInt(child.totalPostCount, 10) || 0;
 			topicCount += parseInt(child.totalTopicCount, 10) || 0;
@@ -222,7 +222,7 @@ async function getChildrenTree(category, uid) {
 	childrenData = childrenData.filter(Boolean);
 	childrenCids = childrenData.map(child => child.cid);
 	const hasRead = await Categories.hasReadCategories(childrenCids, uid);
-	childrenData.forEach(function (child, i) {
+	childrenData.forEach((child, i) => {
 		child['unread-class'] = (child.topic_count === 0 || (hasRead[i] && uid !== 0)) ? '' : 'unread';
 	});
 	Categories.getTree([category].concat(childrenData), category.parentCid);
@@ -270,7 +270,7 @@ Categories.getChildrenCids = async function (rootCid) {
 };
 
 Categories.flattenCategories = function (allCategories, categoryData) {
-	categoryData.forEach(function (category) {
+	categoryData.forEach((category) => {
 		if (category) {
 			allCategories.push(category);
 
@@ -302,7 +302,7 @@ Categories.getTree = function (categories, parentCid) {
 
 	const tree = [];
 
-	categories.forEach(function (category) {
+	categories.forEach((category) => {
 		if (category) {
 			category.children = category.children || [];
 			if (!category.cid) {