Auto create $inject property form the argument names. Any arg starting with $ or _ will be injected

test/InjectorSpec.js

@@ -53,9 +53,56 @@ describe('injector', function(){
 
   it('should autostart eager services', function(){
     var log = '';
-    providers('eager', function(){log += 'eager;'; return 'foo'}, {$eager: true});
+    providers('eager', function(){log += 'eager;'; return 'foo';}, {$eager: true});
     inject();
     expect(log).toEqual('eager;');
     expect(inject('eager')).toBe('foo');
   });
+
+  describe('annotation', function(){
+    it('should return $inject', function(){
+      function fn(){};
+      fn.$inject = ['a'];
+      expect(injectionArgs(fn)).toBe(fn.$inject);
+      expect(injectionArgs(function(){})).toEqual([]);
+    });
+
+    it('should create $inject', function(){
+      // keep the multi-line to make sure we can handle it
+      function $f_n0(
+          $a, // x, <-- looks like an arg but it is a comment
+          b_, /* z, <-- looks like an arg but it is a
+                 multi-line comment
+                 function (a, b){}
+                 */
+          /* {some type} */ c){ extraParans();};
+      expect(injectionArgs($f_n0)).toEqual(['$a', 'b']);
+      expect($f_n0.$inject).toEqual(['$a', 'b']);
+    });
+
+    it('should handle no arg functions', function(){
+      function $f_n0(){};
+      expect(injectionArgs($f_n0)).toEqual([]);
+      expect($f_n0.$inject).toEqual([]);
+    });
+
+    it('should handle args with both $ and _', function(){
+      function $f_n0($a_){};
+      expect(injectionArgs($f_n0)).toEqual(['$a']);
+      expect($f_n0.$inject).toEqual(['$a']);
+    });
+
+    it('should throw on non function arg', function(){
+      expect(function(){
+        injectionArgs({});
+      }).toThrow();
+    });
+
+    it('should throw on injectable after non-injectable arg', function(){
+      expect(function(){
+        injectionArgs(function($a, b_, nonInject, d_){});
+      }).toThrow();
+    });
+
+  });
 });