Core: Handle invalid topics.

core/amplify.core.js

@@ -14,6 +14,10 @@ var slice = [].slice,
 
 var amplify = global.amplify = {
 	publish: function( topic ) {
+		if ( typeof topic !== "string" ) {
+			throw new Error( "You must provide a valid topic to publish." );
+		}
+
 		var args = slice.call( arguments, 1 ),
 			topicSubscriptions,
 			subscription,
@@ -37,6 +41,10 @@ var amplify = global.amplify = {
 	},
 
 	subscribe: function( topic, context, callback, priority ) {
+		if ( typeof topic !== "string" ) {
+			throw new Error( "You must provide a valid topic to create a subscription." );
+		}
+
 		if ( arguments.length === 3 && typeof callback === "number" ) {
 			priority = callback;
 			callback = context;
@@ -83,6 +91,10 @@ var amplify = global.amplify = {
 	},
 
 	unsubscribe: function( topic, callback ) {
+		if ( typeof topic !== "string" ) {
+			throw new Error( "You must provide a valid topic to remove a subscription." );
+		}
+
 		if ( !subscriptions[ topic ] ) {
 			return;
 		}

core/readme.md

@@ -1,6 +1,6 @@
 # amplify core
 
-The AmplifyJS core library provides two methods (`amplify.publish` and `amplify.subscribe`). AmplifyJS provides methods to facilitate the Publish and Subscribe messaging pattern in your front-end application. The idea is that someone is broadcasting one or more messages (publishing) and someone else is listening to one or more messages (subscribing). By separating your logic out like this it allows for loose coupling of your components, which results in less brittle and more reusable code.
+The AmplifyJS core library provides three methods (`amplify.publish`, `amplify.subscribe`, and `amplify.unsubscribe`). AmplifyJS provides methods to facilitate the Publish and Subscribe messaging pattern in your front-end application. The idea is that someone is broadcasting one or more messages (publishing) and someone else is listening to one or more messages (subscribing). By separating your logic out like this it allows for loose coupling of your components, which results in less brittle and more reusable code.
 
 It is possible to implement the publish and subscribe model by using jQuery custom events, however, the AmplifyJS pub/sub component provides a slightly cleaner interface, prevents collisions between custom events and method names, and allows a priority to your messages.
 

core/test/unit.js

@@ -1,5 +1,30 @@
 module( "amplify.core pubsub" );
 
+test( "topic", function() {
+	expect( 3 );
+
+	try {
+		amplify.publish( undefined, function() {} );
+	} catch( err ) {
+		strictEqual( err.message, "You must provide a valid topic to publish.",
+			"error with no topic to publish" );
+	}
+
+	try {
+		amplify.subscribe( undefined, function() {} );
+	} catch( err ) {
+		strictEqual( err.message, "You must provide a valid topic to create a subscription.",
+			"error with no topic to subscribe" );
+	}
+
+	try {
+		amplify.unsubscribe( undefined, function() {} );
+	} catch( err ) {
+		strictEqual( err.message, "You must provide a valid topic to remove a subscription.",
+			"error with no topic to unsubscribe" );
+	}
+});
+
 test( "continuation", function() {
 	expect( 7 );
 	amplify.subscribe( "continuation", function() {