CodeQL documentation

Missing explicit dependency injection

ID: js/angular/missing-explicit-injection
Kind: problem
Severity: warning
Precision: high
Tags:
   - correctness
   - maintainability
   - frameworks/angularjs
Query suites:
   - javascript-security-and-quality.qls

Click to see the query in the CodeQL repository

When AngularJS injects dependencies into a function that does not have an explicit dependency specification, it matches up dependencies with function parameters by name. This is dangerous, since some source code transformations such as minification may change the names of parameters. Such a renaming will break the AngularJS application.

Recommendation

Do not use implicit annotations for dependency injected functions when the code is minified later.

Example

The following example shows an AngularJS controller with implicit dependency annotations.

angular.module('myModule', [])
    .controller('MyController', function($scope) { // BAD: implicit dependency name
        // ...
});

This is problematic, since the minified version of this controller could look like the following:

angular.module('myModule', [])
    .controller('MyController', function(a) { // BAD: dependency 'a' does not exist
        // ...
});

This would mean that the function is dependency-injected with the dependency named “a”, which does not exist, leading to a crash at runtime.

Instead, in order to support minification, specify the dependencies with explicit annotations:

angular.module('myModule', [])
    .controller('MyController', ['$scope', function($scope) { // GOOD: explicit dependency name
        // ...
}]);

References