handling of errors on multi, now returns 'err' array type

Author: thanpolas

index.js

@@ -1011,7 +1011,7 @@ Multi.prototype.HMSET = Multi.prototype.hmset;
 
 Multi.prototype.exec = function (callback) {
     var self = this;
-
+    var errors = [];
     // drain queue, callback will catch "QUEUED" or error
     // TODO - get rid of all of these anonymous functions which are elegant but slow
     this.queue.forEach(function (args, index) {
@@ -1037,12 +1037,7 @@ Multi.prototype.exec = function (callback) {
                 if (typeof cur[cur.length - 1] === "function") {
                     cur[cur.length - 1](err);
                 } else {
-                  if (callback) {
-                      callback(new Error(err));
-                      return;
-                  } else {
-                      throw new Error(err);
-                  }
+                    errors.push(new Error(err));
                 }
                 self.queue.splice(index, 1);
             }
@@ -1053,7 +1048,8 @@ Multi.prototype.exec = function (callback) {
     return this._client.send_command("EXEC", [], function (err, replies) {
         if (err) {
             if (callback) {
-                callback(new Error(err));
+                errors.push(new Error(err));
+                callback(errors);
                 return;
             } else {
                 throw new Error(err);

test.js

@@ -320,6 +320,15 @@ tests.MULTI_7 = function () {
     next(name);
 };
 
+
+tests.MULTI_EXCEPTION_1 = function() {
+  client.multi().set("foo").exec(function (err, reply) {
+    /* ... */
+    console.log('CB:', arguments);
+  });
+  // [Error: Error: ERR wrong number of arguments for 'set' command]
+};
+
 tests.FWD_ERRORS_1 = function () {
     var name = "FWD_ERRORS_1";
 
@@ -615,7 +624,7 @@ tests.detect_buffers = function () {
             assert.strictEqual("<Buffer 76 61 6c 20 31>", reply[0].inspect(), name);
             assert.strictEqual("<Buffer 76 61 6c 20 32>", reply[1].inspect(), name);
         });
-        
+
         // array of strings with undefined values (repro #344)
         detect_client.hmget("hash key 2", "key 3", "key 4", function(err, reply) {
             assert.strictEqual(null, err, name);