Error: Unknown provider: aProvider <- a

I'm using AngularJS in a Ruby on Rails 3.2.8 project with assets.

When I load up my form which is using AngularJS on my development machine I don't have a problem. However when I load the same form up on my production server I get this error in the Javascript console:

Error: Unknown provider: aProvider <- a

I've tracked it back to my coffeescript file where I setup AngularJS for use within a form:

$ (event) ->
  $("#timesheet_description").autocomplete({source: '/autocomplete/work_descs'})

  # Create AngularJS module
  app = angular.module 'timesheetApp', []

  # Create a AngularJS controller
  app.controller "TimesheetCtrl", ($scope) ->
    $scope.costed_amount = 0
                                                                                                # Bind my module to the global variables so I can use it.
  angular.bootstrap document, ["timesheetApp"]

If I comment all this out the page will load without errors and without AngularJS abilities.

Is the problem due to Rails assets compiling and minify? Is there a way to fix this and still use coffeescript and Rails assets?

AngularJS, when using the style you're using right now (called pretotyping), uses the function argument names to do dependency injection. So yes, minification does break this completely.

The fix is simple, though. In every case where you need injection (are using '$xxx') variables, do this:

app.controller "TimesheetCtrl", ['$scope', ($scope) ->
  $scope.costed_amount = 0
]

Basically, replace all function definitions with an array. The last element should be the function definition itself, and the first ones are the $names of the objects you want injected.

There's some more (albeit not clear enough) info on the docs.

If you miss the array notation somewhere , to locate this we need to modify the angular code little bit, but its very quick solution.

change is console.log("Array Notation is Missing",fn); ( line no 11 from function start)

Find out annotate function in angular.js (non-minified)

function annotate(fn) {
      var $inject,
          fnText,
          argDecl,
          last;

      if (typeof fn == 'function') {
        if (!($inject = fn.$inject)) {
          $inject = [];
          if (fn.length) {
console.log("Array Notation is Missing",fn);
fnText = fn.toString().replace(STRIP_COMMENTS, '');
        argDecl = fnText.match(FN_ARGS);
        forEach(argDecl[1].split(FN_ARG_SPLIT), function(arg){
          arg.replace(FN_ARG, function(all, underscore, name){
            $inject.push(name);
          });
        });
      }
      fn.$inject = $inject;
    }
  } else if (isArray(fn)) {
    last = fn.length - 1;
    assertArgFn(fn[last], 'fn');
    $inject = fn.slice(0, last);
  } else {
    assertArgFn(fn, 'fn', true);
  }
  return $inject;
}

To minify angular all you need is to do is to change your declaration to the "array" declaration "mode" for example:

From:

var demoApp= angular.module('demoApp', []);
demoApp.controller(function demoCtrl($scope) {
} );

To

var demoApp= angular.module('demoApp', []);
demoApp.controller(["$scope",function demoCtrl($scope) {
}]);

How to declare factory services?

demoApp.factory('demoFactory', ['$q', '$http', function ($q, $http) {
    return {
          //some object
    };
}]);