Add ESLint

.eslintrc.json

@@ -0,0 +1,28 @@
+{
+  "extends": [
+    "eslint:recommended"
+  ],
+  "plugins": [
+  ],
+  "parserOptions": {
+    "ecmaVersion": 2018,
+    "sourceType": "module"
+  },
+  "env": {
+    "browser": true,
+    "node": true,
+    "es6": true
+  },
+  "rules": {
+    "no-unused-vars": [
+      "warn",
+      {
+        "argsIgnorePattern": "^_",
+        "varsIgnorePattern": "^_",
+        "caughtErrorsIgnorePattern": "^_"
+      }
+    ],
+    "no-cond-assign": "warn",
+    "no-constant-condition": "off"
+  }
+}

.github/workflows/test.yml

@@ -36,3 +36,6 @@ jobs:
 
       # Run the tests
       - run: make test
+
+      # Run linting
+      - run: npm run lint

callback_api.js

@@ -15,7 +15,7 @@ function connect(url, options, cb) {
     if (err === null) cb(null, new CallbackModel(c));
     else cb(err);
   });
-};
+}
 
 module.exports.connect = connect;
 module.exports.credentials = require('./lib/credentials');

channel_api.js

@@ -9,7 +9,7 @@ function connect(url, connOptions) {
   .then(function(conn) {
     return new ChannelModel(conn);
   });
-};
+}
 
 module.exports.connect = connect;
 module.exports.credentials = require('./lib/credentials');

lib/callback_model.js

@@ -4,11 +4,12 @@
 
 'use strict';
 
-var defs = require('./defs');
-var EventEmitter = require('events').EventEmitter;
-var BaseChannel = require('./channel').BaseChannel;
-var acceptMessage = require('./channel').acceptMessage;
-var Args = require('./api_args');
+const util = require('util')
+const defs = require('./defs');
+const EventEmitter = require('events').EventEmitter;
+const BaseChannel = require('./channel').BaseChannel;
+const acceptMessage = require('./channel').acceptMessage;
+const Args = require('./api_args');
 
 class CallbackModel extends EventEmitter {
   constructor (connection) {
@@ -26,7 +27,7 @@ class CallbackModel extends EventEmitter {
 
   createChannel (cb) {
     var ch = new Channel(this.connection);
-    ch.open(function (err, ok) {
+    ch.open(function (err, _ok) {
       if (err === null)
         cb && cb(null, ch);
       else
@@ -132,7 +133,7 @@ class Channel extends BaseChannel {
     this._rpc(defs.ExchangeDeclare,
       Args.assertExchange(ex, type, options),
       defs.ExchangeDeclareOk,
-      function (e, _) { cb(e, { exchange: ex }); });
+      function (e, _ok) { cb(e, { exchange: ex }); });
     return this;
   }
 
@@ -219,7 +220,7 @@ class Channel extends BaseChannel {
         }
         else {
           cb(new Error("Unexpected response to BasicGet: " +
-            inspect(f)));
+            util.inspect(f)));
         }
       }
     });

lib/channel.js

@@ -97,7 +97,7 @@ class Channel extends EventEmitter {
   // Internal, synchronously resolved RPC; the return value is resolved
   // with the whole frame.
   _rpc (method, fields, expect, cb) {
-    var self = this;
+    const self = this;
 
     function reply (err, f) {
       if (err === null) {
@@ -107,9 +107,9 @@ class Channel extends EventEmitter {
         else {
           // We have detected a problem, so it's up to us to close the
           // channel
-          var expectedName = methodName(expect);
+          const expectedName = methodName(expect);
 
-          var e = new Error(fmt("Expected %s; got %s",
+          const e = new Error(fmt("Expected %s; got %s",
             expectedName, inspect(f, false)));
           self.closeWithError(f.id, fmt('Expected %s; got %s',
             expectedName, methodName(f.id)),
@@ -129,12 +129,12 @@ class Channel extends EventEmitter {
       // and the channel is closed by the server
       else {
         // otherwise, it's a close frame
-        var closeReason = (err.fields.classId << 16) + err.fields.methodId;
-        var e = (method === closeReason)
+        const closeReason = (err.fields.classId << 16) + err.fields.methodId;
+        const e = (method === closeReason)
           ? fmt("Operation failed: %s; %s",
             methodName(method), closeMsg(err))
           : fmt("Channel closed by server: %s", closeMsg(err));
-        var closeFrameError = new Error(e);
+        const closeFrameError = new Error(e);
         closeFrameError.code = err.fields.replyCode;
         closeFrameError.classId = err.fields.classId;
         closeFrameError.methodId = err.fields.methodId;
@@ -290,63 +290,67 @@ class Channel extends EventEmitter {
 
     switch (f.id) {
 
-      // Message frames
-    case undefined: // content frame!
-    case defs.BasicDeliver:
-    case defs.BasicReturn:
-    case defs.BasicProperties:
-      return this.acceptMessageFrame(f);
-
-      // confirmations, need to do confirm.select first
-    case defs.BasicAck:
-      return this.emit('ack', f.fields);
-    case defs.BasicNack:
-      return this.emit('nack', f.fields);
-    case defs.BasicCancel:
-      // The broker can send this if e.g., the queue is deleted.
-      return this.emit('cancel', f.fields);
-
-    case defs.ChannelClose:
-      // Any remote closure is an error to us. Reject the pending reply
-      // with the close frame, so it can see whether it was that
-      // operation that caused it to close.
-      if (this.reply) {
-        var reply = this.reply; this.reply = null;
-        reply(f);
+        // Message frames
+      case undefined: // content frame!
+      case defs.BasicDeliver:
+      case defs.BasicReturn:
+      case defs.BasicProperties:
+        return this.acceptMessageFrame(f);
+
+        // confirmations, need to do confirm.select first
+      case defs.BasicAck:
+        return this.emit('ack', f.fields);
+      case defs.BasicNack:
+        return this.emit('nack', f.fields);
+      case defs.BasicCancel:
+        // The broker can send this if e.g., the queue is deleted.
+        return this.emit('cancel', f.fields);
+
+      case defs.ChannelClose: {
+        // Any remote closure is an error to us. Reject the pending reply
+        // with the close frame, so it can see whether it was that
+        // operation that caused it to close.
+        if (this.reply) {
+          const reply = this.reply;
+          this.reply = null;
+          reply(f);
+        }
+        const emsg = "Channel closed by server: " + closeMsg(f);
+        this.sendImmediately(defs.ChannelCloseOk, {});
+
+        const error = new Error(emsg);
+        error.code = f.fields.replyCode;
+        error.classId = f.fields.classId;
+        error.methodId = f.fields.methodId;
+        this.emit('error', error);
+
+        const s = stackCapture(emsg);
+        this.toClosed(s);
+        return;
       }
-      var emsg = "Channel closed by server: " + closeMsg(f);
-      this.sendImmediately(defs.ChannelCloseOk, {});
-
-      var error = new Error(emsg);
-      error.code = f.fields.replyCode;
-      error.classId = f.fields.classId;
-      error.methodId = f.fields.methodId;
-      this.emit('error', error);
-
-      var s = stackCapture(emsg);
-      this.toClosed(s);
-      return;
-
-    case defs.BasicFlow:
-      // RabbitMQ doesn't send this, it just blocks the TCP socket
-      return this.closeWithError(f.id, "Flow not implemented",
-                                 defs.constants.NOT_IMPLEMENTED,
-                                 new Error('Flow not implemented'));
-
-    default: // assume all other things are replies
-      // Resolving the reply may lead to another RPC; to make sure we
-      // don't hold that up, clear this.reply
-      var reply = this.reply; this.reply = null;
-      // however, maybe there's an RPC waiting to go? If so, that'll
-      // fill this.reply again, restoring the invariant. This does rely
-      // on any response being recv'ed after resolving the promise,
-      // below; hence, I use synchronous defer.
-      if (this.pending.length > 0) {
-        var send = this.pending.shift();
-        this.reply = send.reply;
-        this.sendImmediately(send.method, send.fields);
+
+      case defs.BasicFlow:
+        // RabbitMQ doesn't send this, it just blocks the TCP socket
+        return this.closeWithError(f.id, "Flow not implemented",
+            defs.constants.NOT_IMPLEMENTED,
+            new Error('Flow not implemented'));
+
+      default: { // assume all other things are replies
+        // Resolving the reply may lead to another RPC; to make sure we
+        // don't hold that up, clear this.reply
+        const reply = this.reply;
+        this.reply = null;
+        // however, maybe there's an RPC waiting to go? If so, that'll
+        // fill this.reply again, restoring the invariant. This does rely
+        // on any response being recv'ed after resolving the promise,
+        // below; hence, I use synchronous defer.
+        if (this.pending.length > 0) {
+          const send = this.pending.shift();
+          this.reply = send.reply;
+          this.sendImmediately(send.method, send.fields);
+        }
+        return reply(null, f);
       }
-      return reply(null, f);
     }
   }
 }

lib/channel_model.js

@@ -179,6 +179,7 @@ class Channel extends BaseChannel {
       this.unregisterConsumer(consumerTag);
       return ok.fields;
     });
+    return ok
   }
 
   get(queue, options) {

lib/codec.js

@@ -105,7 +105,7 @@ function encodeFieldValue(buffer, value, offset) {
     var start = offset;
     var type = typeof value, val = value;
     // A trapdoor for specifying a type, e.g., timestamp
-    if (value && type === 'object' && value.hasOwnProperty('!')) {
+    if (value && type === 'object' && Object.prototype.hasOwnProperty.call(value, '!')) {
         val = value.value;
         type = value['!'];
     }
@@ -216,7 +216,7 @@ function encodeFieldValue(buffer, value, offset) {
         break;
     case 'decimal':
         tag('D');
-        if (val.hasOwnProperty('places') && val.hasOwnProperty('digits')
+        if (Object.prototype.hasOwnProperty.call(val, 'places') && Object.prototype.hasOwnProperty.call(val, 'digits')
             && val.places >= 0 && val.places < 256) {
             buffer[offset] = val.places; offset++;
             buffer.writeUInt32BE(val.digits, offset); offset += 4;

lib/connect.js

@@ -49,7 +49,7 @@ function openFrames(vhost, query, credentials, extraClientProperties) {
   else
     vhost = QS.unescape(vhost);
 
-  var query = query || {};
+  query = query || {};
 
   function intOrDefault(val, def) {
     return (val === undefined) ? def : parseInt(val);
@@ -146,7 +146,7 @@ function connect(url, socketOptions, openCallback) {
     if (keepAlive) sock.setKeepAlive(keepAlive, keepAliveDelay);
 
     var c = new Connection(sock);
-    c.open(fields, function(err, ok) {
+    c.open(fields, function(err, _ok) {
       // disable timeout once the connection is open, we don't want
       // it fouling things
       if (timeout) sock.setTimeout(0);

lib/connection.js

@@ -474,34 +474,34 @@ class Connection extends EventEmitter {
   }
 
   sendMethod (channel, Method, fields) {
-    var frame = encodeMethod(Method, channel, fields);
+    const frame = encodeMethod(Method, channel, fields);
     this.sentSinceLastCheck = true;
-    var buffer = this.channels[channel].buffer;
+    const buffer = this.channels[channel].buffer;
     return buffer.write(frame);
   }
 
   sendMessage (channel, Method, fields, Properties, props, content) {
     if (!Buffer.isBuffer(content))
       throw new TypeError('content is not a buffer');
 
-    var mframe = encodeMethod(Method, channel, fields);
-    var pframe = encodeProperties(Properties, channel,
+    const mframe = encodeMethod(Method, channel, fields);
+    const pframe = encodeProperties(Properties, channel,
       content.length, props);
-    var buffer = this.channels[channel].buffer;
+    const buffer = this.channels[channel].buffer;
     this.sentSinceLastCheck = true;
 
-    var methodHeaderLen = mframe.length + pframe.length;
-    var bodyLen = (content.length > 0) ?
+    const methodHeaderLen = mframe.length + pframe.length;
+    const bodyLen = (content.length > 0) ?
       content.length + FRAME_OVERHEAD : 0;
-    var allLen = methodHeaderLen + bodyLen;
+    const allLen = methodHeaderLen + bodyLen;
 
     if (allLen < SINGLE_CHUNK_THRESHOLD) {
       // Use `allocUnsafe` to avoid excessive allocations and CPU usage
       // from zeroing. The returned Buffer is not zeroed and so must be
       // completely filled to be used safely.
       // See https://github.com/amqp-node/amqplib/pull/695
-      var all = Buffer.allocUnsafe(allLen);
-      var offset = mframe.copy(all, 0);
+      const all = Buffer.allocUnsafe(allLen);
+      let offset = mframe.copy(all, 0);
       offset += pframe.copy(all, offset);
 
       if (bodyLen > 0)
@@ -514,8 +514,8 @@ class Connection extends EventEmitter {
         // from zeroing. The returned Buffer is not zeroed and so must be
         // completely filled to be used safely.
         // See https://github.com/amqp-node/amqplib/pull/695
-        var both = Buffer.allocUnsafe(methodHeaderLen);
-        var offset = mframe.copy(both, 0);
+        const both = Buffer.allocUnsafe(methodHeaderLen);
+        const offset = mframe.copy(both, 0);
         pframe.copy(both, offset);
         buffer.write(both);
       }