Use built-in error classes to make errors more specific

lib/createClient.js

@@ -12,7 +12,7 @@ module.exports = function createClient (port_arg, host_arg, options) {
             host = host_arg;
         } else {
             if (options && host_arg) {
-                throw new Error('Unknown type of connection in createClient()');
+                throw new TypeError('Unknown type of connection in createClient()');
             }
             options = options || host_arg;
         }
@@ -50,14 +50,14 @@ module.exports = function createClient (port_arg, host_arg, options) {
                         if (options[elem] === parsed.query[elem]) {
                             console.warn('node_redis: WARNING: You passed the ' + elem + ' option twice!');
                         } else {
-                            throw new Error('The ' + elem + ' option is added twice and does not match');
+                            throw new RangeError('The ' + elem + ' option is added twice and does not match');
                         }
                     }
                     options[elem] = parsed.query[elem];
                 }
             }
         } else if (parsed.hostname) {
-            throw new Error('The redis url must begin with slashes "//" or contain slashes after the redis protocol');
+            throw new RangeError('The redis url must begin with slashes "//" or contain slashes after the redis protocol');
         } else {
             options.path = port_arg;
         }
@@ -67,12 +67,12 @@ module.exports = function createClient (port_arg, host_arg, options) {
         options.host = options.host || host_arg;
 
         if (port_arg && arguments.length !== 1) {
-            throw new Error('To many arguments passed to createClient. Please only pass the options object');
+            throw new TypeError('To many arguments passed to createClient. Please only pass the options object');
         }
     }
 
     if (!options) {
-        throw new Error('Unknown type of connection in createClient()');
+        throw new TypeError('Unknown type of connection in createClient()');
     }
 
     return options;

lib/extendedApi.js

@@ -13,7 +13,7 @@ All documented and exposed API belongs in here
 RedisClient.prototype.send_command = RedisClient.prototype.sendCommand = function (command, args, callback) {
     // Throw to fail early instead of relying in order in this case
     if (typeof command !== 'string') {
-        throw new Error('Wrong input type "' + (command !== null && command !== undefined ? command.constructor.name : command) + '" for command name');
+        throw new TypeError('Wrong input type "' + (command !== null && command !== undefined ? command.constructor.name : command) + '" for command name');
     }
     if (!Array.isArray(args)) {
         if (args === undefined || args === null) {
@@ -22,11 +22,11 @@ RedisClient.prototype.send_command = RedisClient.prototype.sendCommand = functio
             callback = args;
             args = [];
         } else {
-            throw new Error('Wrong input type "' + args.constructor.name + '" for args');
+            throw new TypeError('Wrong input type "' + args.constructor.name + '" for args');
         }
     }
     if (typeof callback !== 'function' && callback !== undefined) {
-        throw new Error('Wrong input type "' + (callback !== null ? callback.constructor.name : 'null') + '" for callback function');
+        throw new TypeError('Wrong input type "' + (callback !== null ? callback.constructor.name : 'null') + '" for callback function');
     }
 
     // Using the raw multi command is only possible with this function

lib/multi.js

@@ -46,7 +46,6 @@ function multi_callback (self, err, replies) {
 
     if (err) {
         err.errors = self.errors;
-        err.command = 'EXEC';
         if (self.callback) {
             self.callback(err);
             // Exclude connection errors so that those errors won't be emitted twice
@@ -86,7 +85,7 @@ function multi_callback (self, err, replies) {
 
 Multi.prototype.exec_transaction = function exec_transaction (callback) {
     if (this.monitoring || this._client.monitoring) {
-        var err = new Error(
+        var err = new RangeError(
             'Using transaction with a client that is in monitor mode does not work due to faulty return values of Redis.'
         );
         err.command = 'EXEC';