From e3da70cf3f709c880a57ecf76934d770a76e994b Mon Sep 17 00:00:00 2001
From: Sherlock <lwx_1993@outlook.com>
Date: Tue, 16 Jan 2018 18:04:38 +0800
Subject: [PATCH] Add a subscription after executed only once

---
 src/pubsub.js              | 54 +++++++++++---------------------------
 test/test-subscribeOnce.js | 32 ++++++++++++++++++++++
 2 files changed, 47 insertions(+), 39 deletions(-)
 create mode 100644 test/test-subscribeOnce.js

diff --git a/src/pubsub.js b/src/pubsub.js
index 51a5e6e..367b6e3 100644
--- a/src/pubsub.js
+++ b/src/pubsub.js
@@ -156,44 +156,6 @@ https://github.com/mroderick/PubSubJS
 	 *	Subscribes the passed function to the passed message. Every returned token is unique and should be stored if
 	 *	you need to unsubscribe
 	**/
-<<<<<<< HEAD
-	PubSub.subscribe = function( message, func ){
-		if ( typeof func !== 'function'){
-			return false;
-		}
-
-		// message is not registered yet
-		if ( !messages.hasOwnProperty( message ) ){
-			messages[message] = {};
-		}
-
-		// forcing token as String, to allow for future expansions without breaking usage
-		// and allow for easy use as key names for the 'messages' object
-		var token = 'uid_' + String(++lastUid);
-		messages[message][token] = func;
-
-		// return token for unsubscribing
-		return token;
-	};
-
-	/**
-	 *	PubSub.subscribeOnce( message, func ) -> PubSub
-	 *	- message (String): The message to subscribe to
-	 *	- func (Function): The function to call when a new message is published
-	 *	Subscribes the passed function to the passed message once
-	**/
-	PubSub.subscribeOnce = function( message, func ){
-		let token = pubsub.on( event, function(){
-			// before func apply, unsubscribe message
-			pubsub.unsubscribe( token );
-			func.apply( this, arguments );
-		} );
-
-		return PubSub;
-	}
-
-	/* Public: Clears all subscriptions
-=======
     PubSub.subscribe = function( message, func ){
         if ( typeof func !== 'function'){
             return false;
@@ -213,8 +175,22 @@ https://github.com/mroderick/PubSubJS
         return token;
     };
 
+    /**
+	 *	PubSub.subscribeOnce( message, func ) -> PubSub
+	 *	- message (String): The message to subscribe to
+	 *	- func (Function): The function to call when a new message is published
+	 *	Subscribes the passed function to the passed message once
+	**/
+    PubSub.subscribeOnce = function( message, func ){
+        var token = PubSub.subscribe( message, function(){
+            // before func apply, unsubscribe message
+            PubSub.unsubscribe( token );
+            func.apply( this, arguments );
+        });
+        return PubSub;
+    };
+
     /* Public: Clears all subscriptions
->>>>>>> remote-code/master
 	 */
     PubSub.clearAllSubscriptions = function clearAllSubscriptions(){
         messages = {};
diff --git a/test/test-subscribeOnce.js b/test/test-subscribeOnce.js
new file mode 100644
index 0000000..ab5c9f0
--- /dev/null
+++ b/test/test-subscribeOnce.js
@@ -0,0 +1,32 @@
+'use strict';
+
+var PubSub = require('../src/pubsub'),
+    TestHelper = require('../test/helper'),
+    assert = require('referee').assert,
+    sinon = require('sinon');
+
+
+describe( 'subscribeOnce method', function() {
+
+    it( 'should return PubSub', function() {
+        var func = function(){ return undefined; },
+            message = TestHelper.getUniqueString(),
+            pubSub = PubSub.subscribeOnce( message , func );
+        assert.same( pubSub, PubSub );
+    } );
+
+    it( 'must be executed only once', function() {
+
+        var topic = TestHelper.getUniqueString(),
+            spy = sinon.spy();
+        
+        PubSub.subscribeOnce( topic, spy );
+        for ( var i = 0; i < 3; i++ ) {
+            PubSub.publishSync( topic, TestHelper.getUniqueString() );
+        }
+
+        assert( spy.calledOnce );
+
+    } );
+
+} );
\ No newline at end of file