Typescript definitions (#25)

* Added type definitions

* Handler only has exactly one or no argument

* Moved type defs to root folder

README.md

@@ -71,6 +71,12 @@ emitter.on('foo', onFoo)   // listen
 emitter.off('foo', onFoo)  // unlisten
 ```
 
+### Typescript
+```ts
+import * as mitt from 'mitt';
+let emitter: mitt.Emitter = new mitt();
+```
+
 ## Examples & Demos
 
 <a href="http://codepen.io/developit/pen/rjMEwW?editors=0110">
@@ -79,6 +85,8 @@ emitter.off('foo', onFoo)  // unlisten
   <img src="https://i.imgur.com/CjBgOfJ.png" width="278" alt="preact + mitt preview">
 </a>
 
+* * *
+
 ## API
 
 ### mitt

mitt.d.ts

@@ -0,0 +1,46 @@
+declare var mitt: mitt.MittStatic;
+
+declare module "mitt" {
+    export = mitt;
+}
+
+declare namespace mitt {
+	type Handler = (event?: any) => void;
+
+	interface MittStatic {
+		new(all?: {[key: string]: Handler}): Emitter;
+	}
+
+	interface Emitter {
+		/**
+		 * Register an event handler for the given type.
+		 * 
+		 * @param {string} type Type of event to listen for, or `"*"` for all events.
+		 * @param {Handler} handler Function to call in response to the given event.
+		 * 
+		 * @memberOf Mitt
+		 */
+		on(type: string, handler: Handler): void;
+
+		/**
+		 * Function to call in response to the given event
+		 * 
+		 * @param {string} type Type of event to unregister `handler` from, or `"*"`
+		 * @param {Handler} handler Handler function to remove.
+		 * 
+		 * @memberOf Mitt
+		 */
+		off(type: string, handler: Handler): void;
+
+		/**
+		 * 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
+		 */
+		emit(type: string, event?: any): void;
+	}
+}

package.json

@@ -31,7 +31,8 @@
   "license": "MIT",
   "files": [
     "src",
-    "dist"
+    "dist",
+    "mitt.d.ts"
   ],
   "eslintConfig": {
     "parser": "babel-eslint",
@@ -48,6 +49,7 @@
       "semi": [2, "always"]
     }
   },
+  "typings": "./mitt.d.ts",
   "devDependencies": {
     "babel-core": "^6.9.1",
     "babel-eslint": "^7.1.1",

typings.json

@@ -0,0 +1,5 @@
+{
+  "name": "mitt",
+  "main": "mitt.d.ts",
+  "version": false
+}