refactor: fixes #2, #6, #12 and #13

README.md

@@ -87,16 +87,30 @@ Mitt: Tiny (~200b) functional event emitter / pubsub.
 
 Returns **Mitt**
 
-#### on
+#### emit
+
+Invoke all handlers for the given type.
+If present, `"*"` handlers are invoked prior to type-matched handlers.
+
+**Parameters**
+
+-   `type` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** The event type to invoke
+-   `evt` **\[Any]** Any value (object is recommended and powerful), passed to each handler
+
+Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** the `mitt` instance for chaining
+
+### on
 
 Register an event handler for the given type.
 
 **Parameters**
 
 -   `type` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Type of event to listen for, or `"*"` for all events
--   `handler` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)** Function to call in response to the given event
+-   `handler` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)** Function to call in response to given event
 
-#### off
+Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** the `mitt` instance for chaining
+
+### off
 
 Remove an event handler for the given type.
 
@@ -105,15 +119,7 @@ Remove an event handler for the given type.
 -   `type` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Type of event to unregister `handler` from, or `"*"`
 -   `handler` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)** Handler function to remove
 
-#### emit
-
-Invoke all handlers for the given type.
-If present, `"*"` handlers are invoked prior to type-matched handlers.
-
-**Parameters**
-
--   `type` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** The event type to invoke
--   `event` **\[Any]** An event object, passed to each handler
+Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** the `mitt` instance for chaining
 
 ## Contribute
 First off, thanks for taking the time to contribute!
@@ -139,3 +145,4 @@ Pull requests are the greatest contributions, so be sure they are focused in sco
 ## License
 
 [MIT License](LICENSE.md) © [Jason Miller](https://jasonformat.com/)
+

example.js

@@ -0,0 +1,20 @@
+'use strict'
+
+var mitt = require('./dist/mitt')
+var ee = mitt()
+
+ee
+	.on('*', (type, arg) => console.log('wildcard:', type, arg))
+	.on('foo', (one, c) => console.log('foo1:', one)) // => 1
+	.on('foo', (one) => console.log('foo2:', one)) // => 1
+	.on('bar', (arg) => console.log('bar:', arg)) // => 444
+	.emit('foo', 1, 2, 3) // we not support multiple arguments
+	.emit('bar', 444)
+
+console.log(ee.all)
+
+var emitter = mitt()
+
+console.log(emitter.all) // => {}
+
+emitter.emit('foo', 777)

src/index.js

@@ -1,47 +1,53 @@
 /** Mitt: Tiny (~200b) functional event emitter / pubsub.
- *	@name mitt
- *	@returns {Mitt}
+ *  @name mitt
+ *  @returns {Mitt}
  */
-export default function mitt(all) {
-	// Arrays of event handlers, keyed by type
-	all = all || {};
+export default function mitt () {
+	let all = Object.create(null)
+	let ret = {
+		all,
 
-	// Get or create a named handler list
-	function list(type) {
-		let t = type.toLowerCase();
-		return all[t] || (all[t] = []);
-	}
-
-	return {
-
-		/** Register an event handler for the given type.
-		 *	@param {String} type		Type of event to listen for, or `"*"` for all events
-		 *	@param {Function} handler	Function to call in response to the given event
-		 *	@memberof mitt
+		/**
+		 * Register an event handler for the given type.
+		 *
+		 * @param  {String} type    Type of event to listen for, or `"*"` for all events
+		 * @param  {Function} handler Function to call in response to given event
+		 * @return {Object} the `mitt` instance for chaining
+		 * @memberOf mitt
 		 */
 		on(type, handler) {
-			list(type).push(handler);
+			(all[type] || (all[type] = [])).push(handler);
+			return ret;
 		},
 
-		/** Remove an event handler for the given type.
-		 *	@param {String} type		Type of event to unregister `handler` from, or `"*"`
-		 *	@param {Function} handler	Handler function to remove
-		 *	@memberof mitt
+		/**
+		 * Remove an event handler for the given type.
+		 *
+		 * @param  {String} type    Type of event to unregister `handler` from, or `"*"`
+		 * @param  {Function} handler Handler function to remove
+		 * @return {Object} the `mitt` instance for chaining
+		 * @memberOf mitt
 		 */
 		off(type, handler) {
-			let e = list(type),
-				i = e.indexOf(handler);
-			if (~i) e.splice(i, 1);
+			let e = all[type] || (all[type] = []);
+			e.splice(e.indexOf(handler) >>> 0, 1);
+			return ret;
 		},
 
-		/** Invoke all handlers for the given type.
-		 *	If present, `"*"` handlers are invoked prior to type-matched handlers.
-		 *	@param {String} type	The event type to invoke
-		 *	@param {Any} [event]	An event object, passed to each handler
-		 *	@memberof mitt
+		/**
+		 * Invoke all handlers for the given type.
+		 * If present, `"*"` handlers are invoked prior to type-matched handlers.
+		 *
+		 * @param {String} type  The event type to invoke
+		 * @param {Any} [evt]  Any value (object is recommended and powerful), passed to each handler
+		 * @return {Object} the `mitt` instance for chaining
+		 * @memberof mitt
 		 */
-		emit(type, event) {
-			list('*').concat(list(type)).forEach( f => { f(event); });
+		emit(type, evt) {
+			(all[type] || []).map((handler) => { handler(evt); });
+			(all['*'] || []).map((handler) => { handler(type, evt); });
+			return ret;
 		}
 	};
+	return ret;
 }