Angular.js directives will break on minification unless you do it like this

This page http://docs.angularjs.org/guide/di is a good starting point.

Angular makes extensive use of dependency injection. The unit of DI in Angular is called a provider. A provider is a function that can be injected and takes it's dependencies as arguments. The function then performs a provider role specific action when invoked.

The specific problem here is when the developer relies on Angular to infer dependencies. Angular does this by converting a function reference to a string which returns the full source of the function. It then parses the function parameter names and resolves those as dependencies.

The canonical example of this is an Angular controller (which is one of the provider roles).

  someModule.controller('ControllerName', function($scope, $http) {
    $http.get('/something').
      success(function(response) {
        $scope.someProperty = response.data;
      };
  });

A minimizer changes the above to something more like this:

  someModule.controller('ControllerName', function(a, b) {
    b.get('/something').
      success(function(c) {
        a.someProperty = c.data;
      };
  });

When angular parses that it sees a symbol named 'a' and tries to resolve that as a dependency.

As I mentioned elsewhere, everywhere Angular takes a function as a provider it also takes an array. The array is expected to be a list of dependency named and a function. I've found that the DRYest way to declare a provider is like this:

  someModule.controller('ControllerName', ['$scope', '$http', function($scope, $http) {
    $http.get('/something').
      success(function(response) {
        $scope.someProperty = response.data;
      };
   }]);

Because minifiers don't dare touch strings, the dependency declaration is not modified. The minified code would look something like this:

  someModule.controller('ControllerName', ['$scope', '$http', function(a, b) {
    b.get('/something').
      success(function(c) {
        a.someProperty = c.data;
      };
   }]);

The order of the dependency declarations matters of course because they will be passed to the function and bound to those variables.

Probably a longer answer than you were expecting but I hope it helps. :)