Add redis error codes to the errors

index.js

@@ -500,12 +500,19 @@ RedisClient.prototype.connection_gone = function (why) {
     this.retry_timer = setTimeout(retry_connection, this.retry_delay, this);
 };
 
+var err_code = /^([A-Z]+)\s+(.+)$/;
 RedisClient.prototype.return_error = function (err) {
     var command_obj = this.command_queue.shift(), queue_len = this.command_queue.length;
     if (command_obj.command && command_obj.command.toUpperCase) {
         err.command_used = command_obj.command.toUpperCase();
     }
 
+    var match = err.message.match(err_code);
+    // LUA script could return user errors that don't behave like all other errors!
+    if (match) {
+        err.code = match[1];
+    }
+
     if (this.pub_sub_mode === false && queue_len === 0) {
         this.command_queue = new Queue();
         this.emit("idle");

test/commands/eval.spec.js

@@ -52,7 +52,11 @@ describe("The 'eval' method", function () {
 
             it('converts lua error to an error response', function (done) {
                 helper.serverVersionAtLeast.call(this, client, [2, 5, 0]);
-                client.eval("return {err='this is an error'}", 0, helper.isError(done));
+                client.eval("return {err='this is an error'}", 0, function(err) {
+                    assert(err.code === undefined);
+                    helper.isError()(err);
+                    done();
+                });
             });
 
             it('represents a lua table appropritely', function (done) {

test/commands/keys.spec.js

@@ -14,6 +14,9 @@ describe("The 'keys' method", function () {
             var client;
 
             beforeEach(function (done) {
+                args = args || {};
+                // This is going to test if the high water is also respected
+                args.command_queue_high_water = 100;
                 client = redis.createClient.apply(redis.createClient, args);
                 client.once("connect", function () {
                     client.flushdb(done);