Add stricter/better ESLint config (#589)

* Add stricter/better ESLint config

* Remove more unnecessary @returns

.eslintrc.json

@@ -1,20 +1,133 @@
 {
-  "extends": "airbnb",
+  "extends": "eslint:recommended",
-  "plugins": [
+  "parserOptions": {
-    "import",
+    "ecmaVersion": 6
-    "react",
+  },
-    "jsx-a11y"
+  "env": {
-  ],
+    "es6": true,
+    "node": true
+  },
   "rules": {
-    "max-len": [2, 120, 2],
+    "no-extra-parens": ["warn", "all", {
-    "no-underscore-dangle": 0,
+      "nestedBinaryExpressions": false
-    "global-require": 0,
+    }],
-    "guard-for-in": 0,
+    "valid-jsdoc": ["error", {
-    "no-restricted-syntax": 0,
+      "requireReturn": false,
-    "no-param-reassign": 0,
+      "requireReturnDescription": false,
-    "consistent-return": 0,
+      "preferType": {
-    "import/no-extraneous-dependencies": 0,
+        "String": "string",
-    "no-continue": 0,
+        "Number": "number",
-    "no-confusing-arrow" : 0
+        "Boolean": "boolean",
+        "Function": "function",
+        "object": "Object",
+        "date": "Date",
+        "error": "Error"
+      },
+      "prefer": {
+        "return": "returns"
+      }
+    }],
+
+    "accessor-pairs": "warn",
+    "array-callback-return": "error",
+    "complexity": "warn",
+    "consistent-return": "error",
+    "curly": ["error", "multi-line", "consistent"],
+    "dot-location": ["error", "property"],
+    "dot-notation": "error",
+    "eqeqeq": "error",
+    "no-empty-function": "error",
+    "no-floating-decimal": "error",
+    "no-implied-eval": "error",
+    "no-invalid-this": "error",
+    "no-lone-blocks": "error",
+    "no-multi-spaces": "error",
+    "no-new-func": "error",
+    "no-new-wrappers": "error",
+    "no-new": "error",
+    "no-octal-escape": "error",
+    "no-return-assign": "error",
+    "no-self-compare": "error",
+    "no-sequences": "error",
+    "no-throw-literal": "error",
+    "no-unmodified-loop-condition": "error",
+    "no-unused-expressions": "error",
+    "no-useless-call": "error",
+    "no-useless-concat": "error",
+    "no-useless-escape": "error",
+    "no-void": "error",
+    "no-warning-comments": "warn",
+    "wrap-iife": "error",
+    "yoda": "error",
+
+    "no-label-var": "error",
+    "no-shadow": "error",
+    "no-undef-init": "error",
+
+    "callback-return": "error",
+    "handle-callback-err": "error",
+    "no-mixed-requires": "error",
+    "no-new-require": "error",
+    "no-path-concat": "error",
+    "no-process-env": "error",
+
+    "array-bracket-spacing": "error",
+    "block-spacing": "error",
+    "brace-style": ["error", "1tbs", { "allowSingleLine": true }],
+    "comma-dangle": ["error", "always-multiline"],
+    "comma-spacing": "error",
+    "comma-style": "error",
+    "computed-property-spacing": "error",
+    "consistent-this": ["error", "$this"],
+    "eol-last": "error",
+    "func-names": "error",
+    "func-style": ["error", "declaration", { "allowArrowFunctions": true }],
+    "indent": ["error", 2, { "SwitchCase": 1 }],
+    "key-spacing": "error",
+    "keyword-spacing": "error",
+    "max-depth": "error",
+    "max-len": ["error", 120, 2],
+    "max-nested-callbacks": ["error", { "max": 4 }],
+    "max-statements-per-line": ["error", { "max": 2 }],
+    "new-cap": "error",
+    "newline-per-chained-call": ["error", { "ignoreChainWithDepth": 3 }],
+    "no-array-constructor": "error",
+    "no-inline-comments": "error",
+    "no-lonely-if": "error",
+    "no-mixed-operators": "error",
+    "no-multiple-empty-lines": ["error", { "max": 2, "maxEOF": 1, "maxBOF": 0 }],
+    "no-new-object": "error",
+    "no-spaced-func": "error",
+    "no-trailing-spaces": "error",
+    "no-unneeded-ternary": "error",
+    "no-whitespace-before-property": "error",
+    "object-curly-spacing": ["error", "always"],
+    "operator-assignment": "error",
+    "operator-linebreak": ["error", "after"],
+    "padded-blocks": ["error", "never"],
+    "quote-props": ["error", "as-needed"],
+    "quotes": ["error", "single", { "avoidEscape": true, "allowTemplateLiterals": true }],
+    "semi-spacing": "error",
+    "semi": "error",
+    "space-before-blocks": "error",
+    "space-before-function-paren": ["error", "never"],
+    "space-in-parens": "error",
+    "space-infix-ops": "error",
+    "space-unary-ops": "error",
+    "spaced-comment": "error",
+    "unicode-bom": "error",
+
+    "arrow-body-style": "error",
+    "arrow-spacing": "error",
+    "no-duplicate-imports": "error",
+    "no-useless-computed-key": "error",
+    "no-useless-constructor": "error",
+    "prefer-arrow-callback": "error",
+    "prefer-rest-params": "error",
+    "prefer-spread": "error",
+    "prefer-template": "error",
+    "rest-spread-spacing": "error",
+    "template-curly-spacing": "error",
+    "yield-star-spacing": "error"
   }
 }

.travis.yml

@@ -4,5 +4,4 @@ node_js:
 cache:
   directories:
     - node_modules
-before_install: npm install -g eslint eslint-config-airbnb eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react
+install: npm install
-install: npm install

package.json

@@ -34,11 +34,7 @@
   "devDependencies": {
     "fs-extra": "^0.30.0",
     "jsdoc-parse": "^1.2.0",
-    "eslint": "^3.4.0",
+    "eslint": "^3.4.0"
-    "eslint-config-airbnb": "^10.0.0",
-    "eslint-plugin-import": "^1.14.0",
-    "eslint-plugin-react": "^6.2.0",
-    "eslint-plugin-jsx-a11y": "^2.2.0"
   },
   "optionalDependencies": {
     "node-opus": "^0.1.13"

src/client/Client.js

@@ -117,7 +117,7 @@ class Client extends EventEmitter {
    * @param  {string} emailOrToken The email or token used for the account. If it is an email, a password _must_ be
    * provided.
    * @param  {string} [password] The password for the account, only needed if an email was provided.
-   * @return {Promise<string>}
+   * @returns {Promise<string>}
    * @example
    * // log the client in using a token
    * const token = 'my token';
@@ -128,13 +128,13 @@ class Client extends EventEmitter {
    * const password = 'supersecret123';
    * client.login(email, password);
    */
-  login(email, password) {
+  login(emailOrToken, password) {
     if (password) {
       // login with email and password
-      return this.rest.methods.loginEmailPassword(email, password);
+      return this.rest.methods.loginEmailPassword(emailOrToken, password);
     }
     // login with token
-    return this.rest.methods.loginToken(email);
+    return this.rest.methods.loginToken(emailOrToken);
   }
 
   /**
@@ -174,7 +174,7 @@ class Client extends EventEmitter {
   }
 
   syncGuilds(guilds = this.guilds.array()) {
-    return this.ws.send({
+    this.ws.send({
       op: 12,
       d: guilds.map(g => g.id),
     });
@@ -184,7 +184,7 @@ class Client extends EventEmitter {
    * Caches a user, or obtains it from the cache if it's already cached.
    * If the user isn't already cached, it will only be obtainable by OAuth bot accounts.
    * @param {string} id The ID of the user to obtain
-   * @return {Promise<User>}
+   * @returns {Promise<User>}
    */
   fetchUser(id) {
     if (this.users.has(id)) return Promise.resolve(this.users.get(id));

src/client/ClientDataResolver.js

@@ -20,6 +20,7 @@ class ClientDataResolver {
   constructor(client) {
     this.client = client;
   }
+
   /**
    * Data that resolves to give a User object. This can be:
    * * A User object
@@ -80,15 +81,14 @@ class ClientDataResolver {
    * * A User object
    * @typedef {Guild} GuildMemberResolvable
    */
+
   /**
    * Resolves a GuildMemberResolvable to a GuildMember object
    * @param {GuildResolvable} guild the guild that the member is part of
    * @param {UserResolvable} user the user that is part of the guild
    * @returns {?GuildMember}
    */
-  resolveGuildMember($guild, $user) {
+  resolveGuildMember(guild, user) {
-    let guild = $guild;
-    let user = $user;
     if (user instanceof GuildMember) {
       return user;
     }
@@ -112,7 +112,7 @@ class ClientDataResolver {
 
   /**
    * Resolves a Base64Resolvable to a Base 64 image
-   * @param {Base64Resolvable} dataResolvable the base 64 resolvable you want to resolve
+   * @param {Base64Resolvable} data the base 64 resolvable you want to resolve
    * @returns {?string}
    */
   resolveBase64(data) {
@@ -132,7 +132,7 @@ class ClientDataResolver {
 
   /**
    * Resolves a ChannelResolvable to a Channel object
-   * @param {ChannelResolvable} channelResolvable the channel resolvable to resolve
+   * @param {ChannelResolvable} channel the channel resolvable to resolve
    * @returns {?Channel}
    */
   resolveChannel(channel) {
@@ -157,7 +157,7 @@ class ClientDataResolver {
 
   /**
    * Resolves a StringResolvable to a string
-   * @param {StringResolvable} StringResolvable the string resolvable to resolve
+   * @param {StringResolvable} data the string resolvable to resolve
    * @returns {string}
    */
   resolveString(data) {
@@ -176,13 +176,13 @@ class ClientDataResolver {
    * Data that can be resolved to give a Buffer. This can be:
    * * A Buffer
    * * The path to a local file
-   * * An URL
+   * * A URL
    * @typedef {string|Buffer} FileResolvable
    */
 
   /**
    * Resolves a FileResolvable to a Buffer
-   * @param {FileResolvable} fileResolvable the file resolvable to resolve
+   * @param {FileResolvable} resource the file resolvable to resolve
    * @returns {string|Buffer}
    */
   resolveFile(resource) {
@@ -190,20 +190,18 @@ class ClientDataResolver {
       return new Promise((resolve, reject) => {
         if (/^https?:\/\//.test(resource)) {
           request.get(resource)
-          .set('Content-Type', 'blob')
+            .set('Content-Type', 'blob')
-          .end((err, res) => err ? reject(err) : resolve(res.body));
+            .end((err, res) => err ? reject(err) : resolve(res.body));
         } else {
           const file = path.resolve(resource);
           const stat = fs.statSync(file);
           if (!stat.isFile()) {
-            return reject(new Error(`The file could not be found: ${file}`));
+            reject(new Error(`The file could not be found: ${file}`));
+            return;
           }
 
           fs.readFile(file, (err, data) => {
-            if (err) {
+            if (err) reject(err); else resolve(data);
-              return reject(err);
-            }
-            resolve(data);
           });
         }
       });

src/client/ClientManager.js

@@ -24,7 +24,6 @@ class ClientManager {
    * @param {string} token the authorization token
    * @param {function} resolve function to run when connection is successful
    * @param {function} reject function to run when connection fails
-   * @returns {void}
    */
   connectToWebSocket(token, resolve, reject) {
     this.client.token = token;
@@ -41,7 +40,6 @@ class ClientManager {
   /**
    * Sets up a keep-alive interval to keep the Client's connection valid
    * @param {number} time the interval in milliseconds at which heartbeat packets should be sent
-   * @returns {void}
    */
   setupKeepAlive(time) {
     this.heartbeatInterval = this.client.setInterval(() => {

src/client/rest/RESTMethods.js

@@ -417,9 +417,7 @@ class RESTMethods {
         }
       };
       this.rest.client.on(Constants.Events.GUILD_BAN_REMOVE, listener);
-      this.rest.makeRequest('del', `${Constants.Endpoints.guildBans(guild.id)}/${member.id}`, true)
+      this.rest.makeRequest('del', `${Constants.Endpoints.guildBans(guild.id)}/${member.id}`, true).catch(reject);
-        .then(() => {})
-        .catch(reject);
     });
   }
 

src/client/rest/RequestHandlers/RequestHandler.js

@@ -41,7 +41,7 @@ class RequestHandler {
    * Attempts to get this RequestHandler to process its current queue
    */
   handle() {
-
+    return;
   }
 }
 

src/client/voice/ClientVoiceManager.js

@@ -99,12 +99,13 @@ class ClientVoiceManager {
   /**
    * Sets up a request to join a voice channel
    * @param {VoiceChannel} channel the voice channel to join
-   * @returns {void}
+   * @returns {Promise<VoiceConnection>}
    */
   joinChannel(channel) {
     return new Promise((resolve, reject) => {
       if (this.pending.get(channel.guild.id)) {
-        return reject(new Error('already connecting to a channel in this guild'));
+        reject(new Error('already connecting to a channel in this guild'));
+        return;
       }
       const existingConn = this.connections.get(channel.guild.id);
       if (existingConn) {
@@ -112,7 +113,8 @@ class ClientVoiceManager {
           this._sendWSJoin(channel);
           this.connections.get(channel.guild.id).channel = channel;
         }
-        return resolve(existingConn);
+        resolve(existingConn);
+        return;
       }
       this.pending.set(channel.guild.id, {
         channel,

src/client/voice/VoiceConnection.js

@@ -65,24 +65,22 @@ class VoiceConnection extends EventEmitter {
   /**
    * Executed whenever an error occurs with the UDP/WebSocket sub-client
    * @private
-   * @param {Error} error
+   * @param {Error} err The error that occurred
-   * @returns {void}
    */
-  _onError(e) {
+  _onError(err) {
-    this._reject(e);
+    this._reject(err);
     /**
      * Emitted whenever the connection encounters a fatal error.
      * @event VoiceConnection#error
      * @param {Error} error the encountered error
      */
-    this.emit('error', e);
+    this.emit('error', err);
-    this._shutdown(e);
+    this._shutdown(err);
   }
 
   /**
    * Disconnects the Client from the Voice Channel
    * @param {string} [reason='user requested'] the reason of the disconnection
-   * @returns {void}
    */
   disconnect(reason = 'user requested') {
     this.manager.client.ws.send({
@@ -94,7 +92,7 @@ class VoiceConnection extends EventEmitter {
         self_deaf: false,
       },
     });
-    return this._shutdown(reason);
+    this._shutdown(reason);
   }
 
   _onClose(e) {
@@ -122,7 +120,6 @@ class VoiceConnection extends EventEmitter {
 
   /**
    * Binds listeners to the WebSocket and UDP sub-clients
-   * @returns {void}
    * @private
    */
   bindListeners() {
@@ -208,7 +205,7 @@ class VoiceConnection extends EventEmitter {
 
   /**
    * Play the given file in the voice connection
-   * @param {string} filepath the path to the file
+   * @param {string} file the path to the file
    * @returns {StreamDispatcher}
    * @example
    * // play files natively

src/client/voice/VoiceConnectionUDPClient.js

@@ -16,7 +16,8 @@ class VoiceConnectionUDPClient extends EventEmitter {
   dnsLookup() {
     dns.lookup(this.voiceConnection.endpoint, (err, address) => {
       if (err) {
-        return this.emit('error', err);
+        this.emit('error', err);
+        return;
       }
       this.connectUDP(address);
     });
@@ -27,7 +28,7 @@ class VoiceConnectionUDPClient extends EventEmitter {
       try {
         this.udpSocket.send(packet, 0, packet.length, this.data.port, this.udpIP);
       } catch (err) {
-        return this.emit('error', err);
+        this.emit('error', err);
       }
     }
   }

src/client/voice/VoiceConnectionWebSocket.js

@@ -51,16 +51,18 @@ class VoiceConnectionWebSocket extends EventEmitter {
     });
   }
 
-  _onClose(e) {
+  _onClose(err) {
     if (!this.opened && this.attempts >= 0) {
-      return this.setupWS();
+      this.setupWS();
+      return;
     }
-    this.emit('close', e);
+    this.emit('close', err);
   }
 
   _onError(e) {
     if (!this.opened && this.attempts >= 0) {
-      return this.setupWS();
+      this.setupWS();
+      return;
     }
     this.emit('error', e);
   }
@@ -83,7 +85,8 @@ class VoiceConnectionWebSocket extends EventEmitter {
     try {
       packet = JSON.parse(event.data);
     } catch (error) {
-      return this._onError(error);
+      this._onError(error);
+      return;
     }
 
     switch (packet.op) {

src/client/voice/dispatcher/StreamDispatcher.js

@@ -62,15 +62,18 @@ class StreamDispatcher extends EventEmitter {
   _send() {
     try {
       if (this._triggered) {
-        return this._setSpeaking(false);
+        this._setSpeaking(false);
+        return;
       }
       const data = this.streamingData;
       if (data.missed >= 5) {
-        return this._triggerTerminalState('error', new Error('stream is not generating fast enough'));
+        this._triggerTerminalState('error', new Error('stream is not generating fast enough'));
+        return;
       }
       if (this.paused) {
-        data.timestamp = (data.timestamp + 4294967295) ? data.timestamp + 960 : 0;
+        data.timestamp = data.timestamp + 4294967295 ? data.timestamp + 960 : 0;
-        return this.player.connection.manager.client.setTimeout(() => this._send(), data.length * 10);
+        this.player.connection.manager.client.setTimeout(() => this._send(), data.length * 10);
+        return;
       }
       const bufferLength = 1920 * data.channels;
       this._setSpeaking(true);
@@ -78,7 +81,8 @@ class StreamDispatcher extends EventEmitter {
 
       if (!buffer) {
         data.missed++;
-        return this.player.connection.manager.client.setTimeout(() => this._send(), data.length * 10);
+        this.player.connection.manager.client.setTimeout(() => this._send(), data.length * 10);
+        return;
       }
 
       data.missed = 0;
@@ -91,7 +95,7 @@ class StreamDispatcher extends EventEmitter {
 
       data.count++;
       data.sequence = (data.sequence + 1) < (65536) ? data.sequence + 1 : 0;
-      data.timestamp = (data.timestamp + 4294967295) ? data.timestamp + 960 : 0;
+      data.timestamp = data.timestamp + 4294967295 ? data.timestamp + 960 : 0;
 
       this._sendBuffer(buffer, data.sequence, data.timestamp);
 
@@ -114,14 +118,14 @@ class StreamDispatcher extends EventEmitter {
   /**
   * Emitted once the stream has encountered an error. Attach a `once` listener to this. Also emits `end`.
   * @event StreamDispatcher#error
-  * @param {Error} error the error encountered
+  * @param {Error} err the error encountered
   */
-  _triggerError(e) {
+  _triggerError(err) {
     this.emit('end');
-    this.emit('error', e);
+    this.emit('error', err);
   }
 
-  _triggerTerminalState(state, e) {
+  _triggerTerminalState(state, err) {
     if (this._triggered) {
       return;
     }
@@ -136,10 +140,10 @@ class StreamDispatcher extends EventEmitter {
     this._setSpeaking(false);
     switch (state) {
       case 'end':
-        this._triggerEnd(e);
+        this._triggerEnd(err);
         break;
       case 'error':
-        this._triggerError(e);
+        this._triggerError(err);
         break;
       default:
         this.emit('error', 'unknown trigger state');
@@ -149,10 +153,11 @@ class StreamDispatcher extends EventEmitter {
 
   _startStreaming() {
     if (!this.stream) {
-      return this.emit('error', 'no stream');
+      this.emit('error', 'no stream');
+      return;
     }
-    this.stream.on('end', e => this._triggerTerminalState('end', e));
+    this.stream.on('end', err => this._triggerTerminalState('end', err));
-    this.stream.on('error', e => this._triggerTerminalState('error', e));
+    this.stream.on('error', err => this._triggerTerminalState('error', err));
     const data = this.streamingData;
     data.length = 20;
     data.missed = 0;
@@ -172,7 +177,6 @@ class StreamDispatcher extends EventEmitter {
 
   /**
    * Stops the current stream permanently and emits an `end` event.
-   * @returns {void}
    */
   end() {
     this._triggerTerminalState('end', 'user requested');
@@ -180,7 +184,6 @@ class StreamDispatcher extends EventEmitter {
 
   /**
    * Stops sending voice packets to the voice connection (stream may still progress however)
-   * @returns {void}
    */
   pause() {
     this._pause(true);
@@ -188,7 +191,6 @@ class StreamDispatcher extends EventEmitter {
 
   /**
    * Resumes sending voice packets to the voice connection (may be further on in the stream than when paused)
-   * @returns {void}
    */
   resume() {
     this._pause(false);

src/client/voice/opus/OpusEngineList.js

@@ -11,7 +11,7 @@ function fetch(Encoder) {
   try {
     return new Encoder();
   } catch (err) {
-    return;
+    return null;
   }
 }
 

src/client/voice/pcm/FfmpegConverterEngine.js

@@ -7,6 +7,7 @@ function chooseCommand() {
       return cmd;
     }
   }
+  return null;
 }
 
 class FfmpegConverterEngine extends ConverterEngine {

src/client/voice/player/BasePlayer.js

@@ -70,11 +70,12 @@ class VoiceConnectionPlayer extends EventEmitter {
             streams.inputStream.destroy();
             this.emit('debug', 'stream kill part 5/5 pass');
           }
-        } catch (e) {
+        } catch (err) {
-          return e;
+          return err;
         }
       }
     }
+    return null;
   }
 
   setSpeaking(value) {

src/client/voice/receiver/VoiceReadable.js

@@ -8,6 +8,7 @@ class VoiceReadable extends Readable {
   }
 
   _read() {
+    return;
   }
 
   $push(d) {

src/client/voice/receiver/VoiceReceiver.js

@@ -91,7 +91,8 @@ class VoiceReceiver extends EventEmitter {
        * @event VoiceReceiver#warn
        * @param {string} message the warning message
        */
-      return this.emit('warn', 'failed to decrypt voice packet');
+      this.emit('warn', 'failed to decrypt voice packet');
+      return;
     }
     data = new Buffer(data);
       /**

src/client/websocket/WebSocketManager.js

@@ -49,7 +49,6 @@ class WebSocketManager {
   /**
    * Connects the client to a given gateway
    * @param {string} gateway the gateway to connect to
-   * @returns {void}
    */
   connect(gateway) {
     this.status = Constants.Status.CONNECTING;
@@ -68,12 +67,13 @@ class WebSocketManager {
 
   /**
    * Sends a packet to the gateway
-   * @param {Object} packet An object that can be JSON stringified
+   * @param {Object} data An object that can be JSON stringified
-   * @returns {void}
+   * @param {boolean} force Whether or not to send the packet immediately
    */
   send(data, force = false) {
     if (force) {
-      return this.ws.send(JSON.stringify(data));
+      this.ws.send(JSON.stringify(data));
+      return;
     }
     this._queue.push(JSON.stringify(data));
     this.doQueue();
@@ -89,9 +89,10 @@ class WebSocketManager {
     const item = this._queue[0];
     if (this.ws.readyState === WebSocket.OPEN && item) {
       if (this._remaining === 0) {
-        return this.client.setTimeout(() => {
+        this.client.setTimeout(() => {
           this.doQueue();
         }, 1000);
+        return;
       }
       this._remaining--;
       this.ws.send(item);
@@ -103,7 +104,6 @@ class WebSocketManager {
 
   /**
    * Run whenever the gateway connections opens up
-   * @returns {void}
    */
   eventOpen() {
     if (this.reconnecting) {
@@ -115,7 +115,6 @@ class WebSocketManager {
 
   /**
    * Sends a gatway resume packet, in cases of unexpected disconnections.
-   * @returns {void}
    */
   _sendResume() {
     const payload = {
@@ -132,7 +131,6 @@ class WebSocketManager {
 
   /**
    * Sends a new identification packet, in cases of new connections or failed reconnections.
-   * @returns {void}
    */
   _sendNewIdentify() {
     this.reconnecting = false;
@@ -150,7 +148,7 @@ class WebSocketManager {
 
   /**
    * Run whenever the connection to the gateway is closed, it will try to reconnect the client.
-   * @returns {void}
+   * @param {Object} event the event
    */
   eventClose(event) {
     if (event.code === 4004) {
@@ -164,12 +162,11 @@ class WebSocketManager {
   /**
    * Run whenever a message is received from the WebSocket. Returns `true` if the message
    * was handled properly.
-   * @param {Object} data the received websocket data
+   * @param {Object} event the received websocket data
    * @returns {boolean}
    */
-  eventMessage($event) {
+  eventMessage(event) {
     let packet;
-    const event = $event;
     try {
       if (event.binary) {
         event.data = zlib.inflateSync(event.data).toString();
@@ -191,15 +188,15 @@ class WebSocketManager {
 
   /**
    * Run whenever an error occurs with the WebSocket connection. Tries to reconnect
-   * @returns {void}
+   * @param {Error} err the error that occurred
    */
-  eventError(e) {
+  eventError(err) {
     /**
      * Emitted whenever the Client encounters a serious connection error
      * @event Client#error
      * @param {Error} error the encountered error
      */
-    this.client.emit('error', e);
+    this.client.emit('error', err);
     this.tryReconnect();
   }
 
@@ -217,7 +214,6 @@ class WebSocketManager {
   /**
    * Runs on new packets before `READY` to see if the Client is ready yet, if it is prepares
    * the `READY` event.
-   * @returns {void}
    */
   checkIfReady() {
     if (this.status !== Constants.Status.READY && this.status !== Constants.Status.NEARLY) {
@@ -229,10 +225,11 @@ class WebSocketManager {
         this.status = Constants.Status.NEARLY;
         if (this.client.options.fetch_all_members) {
           const promises = this.client.guilds.array().map(g => g.fetchMembers());
-          return Promise.all(promises).then(() => this._emitReady()).catch(e => {
+          Promise.all(promises).then(() => this._emitReady()).catch(e => {
             this.client.emit('warn', `error on pre-ready guild member fetching - ${e}`);
             this._emitReady();
           });
+          return;
         }
         this._emitReady();
       }
@@ -241,7 +238,6 @@ class WebSocketManager {
 
   /**
    * Tries to reconnect the client, changing the status to Constants.Status.RECONNECTING.
-   * @returns {void}
    */
   tryReconnect() {
     this.status = Constants.Status.RECONNECTING;

src/client/websocket/packets/handlers/ChannelPinsUpdate.js

@@ -20,7 +20,7 @@ class ChannelPinsUpdate extends AbstractHandler {
     const time = new Date(data.last_pin_timestamp);
 
     if (channel && time) {
-      return client.emit(Constants.Events.CHANNEL_PINS_UPDATE, channel, time);
+      client.emit(Constants.Events.CHANNEL_PINS_UPDATE, channel, time);
     }
   }
 

src/client/websocket/packets/handlers/PresenceUpdate.js

@@ -45,14 +45,12 @@ class PresenceUpdateHandler extends AbstractHandler {
     data.user.status = data.status || user.status;
     data.user.game = data.game;
 
-    const same = (
+    const same = data.user.username === user.username &&
-      data.user.username === user.username &&
       data.user.id === user.id &&
       data.user.discriminator === user.discriminator &&
       data.user.avatar === user.avatar &&
       data.user.status === user.status &&
-      JSON.stringify(data.user.game) === JSON.stringify(user.game)
+      JSON.stringify(data.user.game) === JSON.stringify(user.game);
-    );
 
     if (!same) {
       const oldUser = cloneObject(user);

src/client/websocket/packets/handlers/Ready.js

@@ -29,7 +29,7 @@ class ReadyHandler extends AbstractHandler {
 
     this.packetManager.ws.sessionID = data.session_id;
 
-    this.packetManager.ws.checkIfReady('abc');
+    this.packetManager.ws.checkIfReady();
   }
 
 }

src/structures/Channel.js

@@ -37,7 +37,7 @@ class Channel {
 
   /**
    * Deletes the channel
-   * @return {Promise<Channel>}
+   * @returns {Promise<Channel>}
    * @example
    * // delete the channel
    * channel.delete()

src/structures/EvaluatedPermissions.js

@@ -53,7 +53,7 @@ class EvaluatedPermissions {
       }
     }
 
-    return ((this.permissions & permission) > 0);
+    return (this.permissions & permission) > 0;
   }
 }
 

src/structures/GroupDMChannel.js

@@ -54,13 +54,11 @@ class GroupDMChannel extends Channel {
   }
 
   equals(other) {
-    const base = (
+    const base = other &&
-      other &&
       this.id === other.id &&
       this.name === other.name &&
       this.icon === other.icon &&
-      this.owner.id === other.owner_id
+      this.owner.id === other.owner_id;
-    );
 
     if (base) {
       const thisIDs = this.recipients.array().map(r => r.id);

src/structures/Guild.js

@@ -123,10 +123,7 @@ class Guild {
       member.nickname = data.nick;
     }
 
-    const notSame = (
+    const notSame = member.nickname !== oldMember.nickname && !arraysEqual(member._roles, oldMember._roles);
-      member.nickname !== oldMember.nickname &&
-      !arraysEqual(member._roles, oldMember._roles)
-    );
 
     if (this.client.ws.status === Constants.Status.READY && notSame) {
       /**
@@ -183,28 +180,28 @@ class Guild {
    * @param {Guild} guild the guild to compare
    * @returns {boolean}
    */
-  equals(data) {
+  equals(guild) {
     let base =
-      data &&
+      guild &&
-      this.id === data.id &&
+      this.id === guild.id &&
-      this.available === !data.unavailable &&
+      this.available === !guild.unavailable &&
-      this.splash === data.splash &&
+      this.splash === guild.splash &&
-      this.region === data.region &&
+      this.region === guild.region &&
-      this.name === data.name &&
+      this.name === guild.name &&
-      this.memberCount === data.member_count &&
+      this.memberCount === guild.member_count &&
-      this.large === data.large &&
+      this.large === guild.large &&
-      this.icon === data.icon &&
+      this.icon === guild.icon &&
-      arraysEqual(this.features, data.features) &&
+      arraysEqual(this.features, guild.features) &&
-      this.ownerID === data.owner_id &&
+      this.ownerID === guild.owner_id &&
-      this.verificationLevel === data.verification_level &&
+      this.verificationLevel === guild.verification_level &&
-      this.embedEnabled === data.embed_enabled;
+      this.embedEnabled === guild.embed_enabled;
 
     if (base) {
       if (this.embedChannel) {
-        if (this.embedChannel.id !== data.embed_channel_id) {
+        if (this.embedChannel.id !== guild.embed_channel_id) {
           base = false;
         }
-      } else if (data.embed_channel_id) {
+      } else if (guild.embed_channel_id) {
         base = false;
       }
     }
@@ -228,8 +225,7 @@ class Guild {
 
   /**
    * Sets up the Guild
-   * @param {*} data
+   * @param {*} data the raw data of the guild
-   * @returns {void}
    * @private
    */
   setup(data) {
@@ -588,7 +584,8 @@ class Guild {
         throw new Error('already fetching guild members');
       }
       if (this.memberCount === this.members.size) {
-        return resolve(this);
+        resolve(this);
+        return;
       }
       this._fetchWaiter = resolve;
       this.client.ws.send({
@@ -627,7 +624,6 @@ class Guild {
 
   /**
    * Syncs this guild (already done automatically every 30 seconds)
-   * @returns {void}
    */
   sync() {
     this.client.syncGuilds([this]);

src/structures/GuildChannel.js

@@ -65,20 +65,18 @@ class GuildChannel extends Channel {
    * @param {GuildChannel} channel the channel to compare this channel to
    * @returns {boolean}
    */
-  equals(other) {
+  equals(channel) {
-    let base = (
+    let base = channel &&
-      other &&
+      this.type === channel.type &&
-      this.type === other.type &&
+      this.topic === channel.topic &&
-      this.topic === other.topic &&
+      this.position === channel.position &&
-      this.position === other.position &&
+      this.name === channel.name &&
-      this.name === other.name &&
+      this.id === channel.id;
-      this.id === other.id
-    );
 
     if (base) {
-      if (other.permission_overwrites) {
+      if (channel.permission_overwrites) {
         const thisIDSet = Array.from(this.permissionOverwrites.keys());
-        const otherIDSet = other.permission_overwrites.map(overwrite => overwrite.id);
+        const otherIDSet = channel.permission_overwrites.map(overwrite => overwrite.id);
         if (arraysEqual(thisIDSet, otherIDSet)) {
           base = true;
         } else {
@@ -168,7 +166,7 @@ class GuildChannel extends Channel {
   /**
    * Overwrites the permissions for a user or role in this channel.
    * @param {Role|UserResolvable} userOrRole the user or role to update
-   * @param {PermissionOverwriteOptions} config the configuration for the update
+   * @param {PermissionOverwriteOptions} options the configuration for the update
    * @returns {Promise<null, Error>}
    * @example
    * // overwrite permissions for a message author
@@ -205,11 +203,11 @@ class GuildChannel extends Channel {
 
     for (const perm in options) {
       if (options[perm] === true) {
-        payload.allow |= (Constants.PermissionFlags[perm] || 0);
+        payload.allow |= Constants.PermissionFlags[perm] || 0;
         payload.deny &= ~(Constants.PermissionFlags[perm] || 0);
       } else if (options[perm] === false) {
         payload.allow &= ~(Constants.PermissionFlags[perm] || 0);
-        payload.deny |= (Constants.PermissionFlags[perm] || 0);
+        payload.deny |= Constants.PermissionFlags[perm] || 0;
       }
     }
 

src/structures/Message.js

@@ -155,7 +155,7 @@ class Message {
     return new Date(this._editedTimestamp);
   }
 
-  patch(data) {
+  patch(data) { // eslint-disable-line complexity
     if (data.author) {
       this.author = this.client.users.get(data.author.id);
       if (this.guild) {

src/structures/Role.js

@@ -212,7 +212,7 @@ class Role {
       }
     }
 
-    return ((this.permissions & permission) > 0);
+    return (this.permissions & permission) > 0;
   }
 
   /**
@@ -229,7 +229,7 @@ class Role {
    * @readonly
    */
   get hexColor() {
-    let col = (this.color).toString(16);
+    let col = this.color.toString(16);
     while (col.length < 6) {
       col = `0${col}`;
     }

src/structures/User.js

@@ -80,7 +80,7 @@ class User {
 
   /**
    * Deletes a DM Channel (if one exists) between the Client and the User. Resolves with the Channel if successful.
-   * @return {Promise<DMChannel>}
+   * @returns {Promise<DMChannel>}
    */
   deleteDM() {
     return this.client.rest.methods.deleteChannel(this);
@@ -93,14 +93,12 @@ class User {
    * @returns {boolean}
    */
   equals(user) {
-    let base = (
+    let base = user &&
-      user &&
       this.username === user.username &&
       this.id === user.id &&
       this.discriminator === user.discriminator &&
       this.avatar === user.avatar &&
-      this.bot === Boolean(user.bot)
+      this.bot === Boolean(user.bot);
-    );
 
     if (base) {
       if (user.status) {

src/structures/VoiceChannel.js

@@ -59,7 +59,6 @@ class VoiceChannel extends GuildChannel {
 
   /**
    * Leaves this voice channel
-   * @returns {void}
    * @example
    * // leave a voice channel
    * voiceChannel.leave();

src/structures/interface/TextBasedChannel.js

@@ -55,7 +55,7 @@ class MessageCollector extends EventEmitter {
      * @type {boolean}
      */
     this.ended = false;
-    this.listener = (message => this.verify(message));
+    this.listener = message => this.verify(message);
     this.channel.client.on('message', this.listener);
     /**
      * A collection of collected messages, mapped by message ID.
@@ -70,7 +70,7 @@ class MessageCollector extends EventEmitter {
   /**
    * Verifies a message against the filter and options
    * @private
-   * @param {Message} message
+   * @param {Message} message the message
    * @returns {boolean}
    */
   verify(message) {
@@ -258,7 +258,6 @@ class TextBasedChannel {
   /**
    * Starts a typing indicator in the channel.
    * @param {number} [count] The number of times startTyping should be considered to have been called
-   * @returns {void}
    * @example
    * // start typing in a channel
    * channel.startTyping();
@@ -284,7 +283,6 @@ class TextBasedChannel {
    * The indicator will only stop if this is called as many times as startTyping().
    * <info>It can take a few seconds for the Client User to stop typing.</info>
    * @param {boolean} [force=false] whether or not to force the indicator to stop regardless of call count
-   * @returns {void}
    * @example
    * // stop typing in a channel
    * channel.stopTyping();

src/util/Collection.js

@@ -47,7 +47,7 @@ class Collection extends Map {
   /**
    * If the items in this collection have a delete method (e.g. messages), invoke
    * the delete method. Returns an array of promises
-   * @return {Array<Promise>}
+   * @returns {Array<Promise>}
    */
   deleteAll() {
     const returns = [];