From a49cb2848015b55f1cdfae55c0ec0cce077665b5 Mon Sep 17 00:00:00 2001
From: Dylan Carney <dcarney@gmail.com>
Date: Thu, 5 Feb 2015 13:25:01 -0800
Subject: [PATCH] producer: Adds a Ping method in order to validate an nsqd
 connection

Signed-off-by: dcarney <dcarney@gmail.com>
---
 producer.go      | 17 +++++++++++++++++
 producer_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/producer.go b/producer.go
index 964c16d9..1018d26a 100644
--- a/producer.go
+++ b/producer.go
@@ -91,6 +91,23 @@ func NewProducer(addr string, config *Config) (*Producer, error) {
 	return p, nil
 }
 
+// Ping causes the Producer to connect to it's configured nsqd (if not already
+// connected) and send a `Nop` command, returning any error that might occur.
+//
+// This method can be used to verify that a newly-created Producer instance is
+// configured correctly, rather than relying on the lazy "connect on Publish"
+// behavior of a Producer.
+func (w *Producer) Ping() error {
+	if atomic.LoadInt32(&w.state) != StateConnected {
+		err := w.connect()
+		if err != nil {
+			return err
+		}
+	}
+
+	return w.conn.WriteCommand(Nop())
+}
+
 // SetLogger assigns the logger to use as well as a level
 //
 // The logger parameter is an interface that requires the following
diff --git a/producer_test.go b/producer_test.go
index 1371aa2e..04f3db05 100644
--- a/producer_test.go
+++ b/producer_test.go
@@ -3,6 +3,9 @@ package nsq
 import (
 	"bytes"
 	"errors"
+	"io/ioutil"
+	"log"
+	"os"
 	"runtime"
 	"strconv"
 	"sync"
@@ -53,6 +56,28 @@ func TestProducerConnection(t *testing.T) {
 	}
 }
 
+func TestProducerPing(t *testing.T) {
+	log.SetOutput(ioutil.Discard)
+	defer log.SetOutput(os.Stdout)
+
+	config := NewConfig()
+	w, _ := NewProducer("127.0.0.1:4150", config)
+	w.SetLogger(nullLogger, LogLevelInfo)
+
+	err := w.Ping()
+
+	if err != nil {
+		t.Fatalf("should connect on ping")
+	}
+
+	w.Stop()
+
+	err = w.Ping()
+	if err != ErrStopped {
+		t.Fatalf("should not be able to ping after Stop()")
+	}
+}
+
 func TestProducerPublish(t *testing.T) {
 	topicName := "publish" + strconv.Itoa(int(time.Now().Unix()))
 	msgCount := 10