Sample .into(target) implementation for #3

src/index.js

@@ -35,11 +35,29 @@
   }
 
   /**
-   * @return {Energy}
+   * @return {Energy} emitter instance
    */
   function energy(o) {
     return o instanceof Energy ? o[init]() : new Energy(o);
-  }
+  }
+
+  /**
+   * @this {Function} wrapper that constructs the source instance
+   * @param {Object|Function} target to convert into emitter
+   * @return {Object|Function} target converted into emitter
+   */  
+  energy['into'] = function(target) {
+    return defaults(target, this.call());
+  };
+
+  /**
+   * @this {Energy|Object|Function} source emitter
+   * @param {Object|Function} target to convert into emitter
+   * @return {Object|Function} target converted into emitter
+   */  
+  emitter['into'] = function(target) {
+    return defaults(target, this);
+  };
 
   /**
    * @param {{length:number}} fns

test/index.js

@@ -11,7 +11,19 @@
   function yes() { return true; }
 
   aok('instance', emitter instanceof energy);
-  aok('listeners', typeof emitter.listeners(key).length == 'number');
+  aok('listeners', typeof emitter.listeners(key).length == 'number');
+
+  aok('into', function() {
+    function wannabe() {
+      wannabe.emit('called');
+    }
+
+    var bool = wannabe === energy.into(wannabe) && typeof wannabe.emit == 'function';
+    bool && wannabe.once('called', function() {
+      bool = this === wannabe;
+    }) && wannabe();
+    return bool;
+  });
 
   (function(id) {
     var bool = true, gone = indexOf ? function(what) {