Add .command_used to errors thrown by the parser

Author: Ruben Bridgewater

index.js

@@ -509,6 +509,7 @@ RedisClient.prototype.on_data = function (data) {
 
 RedisClient.prototype.return_error = function (err) {
     var command_obj = this.command_queue.shift(), queue_len = this.command_queue.length;
+    err.command_used = command_obj.command.toUpperCase();
 
     if (this.pub_sub_mode === false && queue_len === 0) {
         this.command_queue = new Queue();

test/auth.spec.js

@@ -39,8 +39,9 @@ describe("client authentication", function () {
 
                 client = redis.createClient.apply(redis.createClient, args);
 
-                client.once('error', function (error) {
-                    assert.ok(/ERR invalid password/.test(error));
+                client.once('error', function (err) {
+                    assert.strictEqual(err.command_used, 'AUTH');
+                    assert.ok(/ERR invalid password/.test(err.message));
                     return done();
                 });
 

test/commands/select.spec.js

@@ -94,6 +94,7 @@ describe("The 'select' method", function () {
                             assert.strictEqual(client.selected_db, null, "default db should be null");
 
                             client.on('error', function (err) {
+                                assert.strictEqual(err.command_used, 'SELECT');
                                 assert.equal(err.message, 'ERR invalid DB index');
                                 done();
                             });