docs/content/error/$injector/undef.ngdoc
@ngdoc error
@name $injector:undef
@fullName Undefined Value
@description
This error results from registering a factory which does not return a value (or whose return value is undefined).
The following is an example of a factory which will throw this error upon injection:
```js
angular.module("badModule", []).
factory("badFactory", function() {
doLotsOfThings();
butDontReturnAValue();
});
```
In order to prevent the error, return a value of some sort, such as an object which exposes an API for working
with the injected object.
```js
angular.module("goodModule", []).
factory("goodFactory", function() {
doLotsOfThings();
butDontReturnAValue();
return {
doTheThing: function methodThatDoesAThing() {
}
};
});
```