Add, remove and rebuild AngularJS dependency injection annotations

Module License: MIT





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Olov Lassus
Olov Lassus

Module Description


ng-annotate adds and removes AngularJS dependency injection annotations. It is non-intrusive so your source code stays exactly the same otherwise. No lost comments or moved lines. Annotations are useful because with them you're able to minify your source code using your favorite JS minifier.

You write your code without annotations, like this:

angular.module("MyMod").controller("MyCtrl", function($scope, $timeout) {

You then run ng-annotate as a build-step to produce this intermediary, annotated, result (later sent to the minifier):

angular.module("MyMod").controller("MyCtrl", ["$scope", "$timeout", function($scope, $timeout) {

You can also use ng-annotate to rebuild or remove existing annotations. Rebuilding is useful if you like to check-in the annotated version of your source code. When refactoring, just change parameter names once and let ng-annotate rebuild the annotations. Removing is useful if you want to de-annotate an existing codebase that came with checked-in annotations

*ng-annotate works by using static analysis to identify common code patterns. There are patterns it does not and never will understand and for those you can use an explicit ngInject annotation instead, see section further down.

Installation and usage

npm install -g ng-annotate

Then run it as ng-annotate OPTIONS <file>. The errors (if any) will go to stderr, the transpiled output to stdout.

Use the --add (-a) option to add annotations where non-existing, use --remove (-r) to remove all existing annotations, use --add --remove (-ar) to rebuild all annotations.

Use the -o option to write output to file.

Provide - instead of an input <file> to read input from stdin.

Use the --sourcemap option to generate an inline sourcemap.

Use the --sourceroot option to set the sourceRoot property of the generated sourcemap.

Use the --single_quotes option to output '$scope' instead of "$scope".

Use the --regexp option to restrict matching further or to expand matching. See description further down.

experimental Use the --rename option to rename providers (services, factories, controllers, etc.) with a new name when declared and referenced through annotation. Use it like this: --rename oldname1 newname1 oldname2 newname2

experimental Use the --plugin option to load a user plugin with the provided path, 0.9.x may change API). See plugin-example.js for more info.

experimental Use the --stats option to print statistics on stderr.

Highly recommended: enable ng-strict-di in your minified builds

<div ng-app="myApp" ng-strict-di>

Do that in your ng-annotate processed builds and AngularJS will let you know if there are any missing dependency injection annotations. ng-strict-di is available in AngularJS 1.3 or later.

Tools support



Declaration forms

ng-annotate understands the two common declaration forms:

Long form:

angular.module("MyMod").controller("MyCtrl", function($scope, $timeout) {

Short form:

myMod.controller("MyCtrl", function($scope, $timeout) {

It's not limited to .controller of course. It understands .config, .factory, .directive, .filter, .run, .controller, .provider, .service, .animation and .invoke.

For short forms it does not need to see the declaration of myMod so you can run it on your individual source files without concatenating. If ng-annotate detects a short form false positive then you can use the --regexp option to limit the module identifier. Examples: --regexp "^myMod$" (match only myMod) or --regexp "^$" (ignore short forms). You can also use --regexp to opt-in for more advanced method callee matching, for example --regexp "^require(.*)$" to detect and transform require('app-module').controller(..). Not using the option is the same as passing --regexp "^[a-zA-Z0-9_\$\.\s]+$", which means that the callee can be a (non-unicode) identifier (foo), possibly with dot notation (

ng-annotate understands angular.module("MyMod", function(dep) ..) as an alternative to angular.module("MyMod").config(function(dep) ..).

ng-annotate understands this.$get = function($scope) .. and {.., $get: function($scope) ..} inside a provider. self and that can be used as aliases for this.

ng-annotate understands return {.., controller: function($scope) ..} inside a directive.

ng-annotate understands $provide.decorator("bar", function($scope) ..), $provide.service, $provide.factory and $provide.provider.

ng-annotate understands $routeProvider.when("path", { .. }).

ng-annotate understands $httpProvider.interceptors.push(function($scope) ..) and $httpProvider.responseInterceptors.push(function($scope) ..).

ng-annotate understands $injector.invoke(function ..).

ng-annotate understands ui-router ($stateProvider and $urlRouterProvider).

ng-annotate understands $ (angular-ui/bootstrap).

ng-annotate understands $, $ and $ (angular material design).

ng-annotate understands"MyCtrl", function ..) (flux-angular).

ng-annotate understands chaining.

ng-annotate understands IIFE's and attempts to match through them, so (function() { return function($scope) .. })() works anywhere function($scope) .. does (for any IIFE args and params).


ng-annotate follows references. This works iff the referenced declaration is a) a function declaration or b) a variable declaration with an initializer. Modifications to a reference outside of its declaration site are ignored by ng-annotate.

These examples will get annotated:

function MyCtrl($scope, $timeout) {
var MyCtrl2 = function($scope) {};

angular.module("MyMod").controller("MyCtrl", MyCtrl);
angular.module("MyMod").controller("MyCtrl", MyCtrl2);

Explicit annotations with ngInject

You can prepend a function with /*@ngInject*/ to explicitly state that the function should get annotated. ng-annotate will leave the comment intact and will thus still be able to also remove or rewrite such annotations.

You can also wrap an expression inside an ngInject(..) function call. If you use this syntax then add function ngInject(v) { return v } somewhere in your codebase, or process away the ngInject function call in your build step.

You can also add the "ngInject" directive prologue at the beginning of a function, similar to how "use strict" is used, to state that the surrounding function should get annotated.

Use ngInject to support your code style when it's not in a form ng-annotate understands natively. Remember that the intention of ng-annotate is to reduce stuttering for you, and ngInject does this just as well. You don't need to keep two lists in sync. Use it!

ngInject may be particularly useful if you use a compile-to-JS language that doesn't preserve comments.

Suppressing false positives with ngNoInject

The /*@ngInject*/, ngInject(..) and "ngInject" siblings have three cousins that are used for the opposite purpose, suppressing an annotation that ng-annotate added incorrectly (a "false positive"). They are called /*@ngNoInject*/, ngNoInject(..) and "ngNoInject" and do exactly what you think they do.

ngInject examples

Here follows some ngInject examples using the /*@ngInject*/ syntax. Most examples works fine using the ngInject(..) or "ngInject" syntax as well.

x = /*@ngInject*/ function($scope) {};
obj = {controller: /*@ngInject*/ function($scope) {}}; = /*@ngInject*/ function($scope) {};


x = /*@ngInject*/ ["$scope", function($scope) {}];
obj = {controller: /*@ngInject*/ ["$scope", function($scope) {}]}; = /*@ngInject*/ ["$scope", function($scope) {}];

Prepended to an object literal, /*@ngInject*/ will annotate all of its contained function expressions, recursively:

obj = /*@ngInject*/ {
    controller: function($scope) {},
    resolve: { data: function(Service) {} },


obj = /*@ngInject*/ {
    controller: ["$scope", function($scope) {}],
    resolve: { data: ["Service", function(Service) {}] },

Prepended to a function statement, to a single variable declaration initialized with a function expression or to an assignment where the rvalue is a function expression, /*@ngInject*/ will attach an $inject array to the function:

// @ngInject
function Foo($scope) {}

// @ngInject
var foo = function($scope) {}

// @ngInject
module.exports = function($scope) {}


// @ngInject
function Foo($scope) {}
Foo.$inject = ["$scope"];

// @ngInject
var foo = function($scope) {}
foo.$inject = ["$scope"];

// @ngInject
module.exports = function($scope) {}
module.exports.$inject = ["$scope"];

Build and test

ng-annotate is written in ES6 constlet style and uses defs.js to transpile to ES5. See for build and test instructions.


MIT, see LICENSE file.

ng-annotate is written by Olov Lassus with the kind help by contributors. Follow @olov on Twitter for updates about ng-annotate.

How does ng-annotate compare to ngmin?

ngmin has been deprecated in favor of ng-annotate. In short: ng-annotate is much faster, finds more declarations to annotate (including ui-router), treats your source code better, is actively maintained and has a bunch of extra features on top of that. A much more elaborated answer can be found in "The future of ngmin and ng-annotate".

Migrating from ngmin: ng-annotate -a - is similar to ngmin (use stdin and stdout). ng-annotate -a in.js -o out.js is similar to ngmin in.js out.js. Grunt users can migrate easily by installing grunt-ng-annotate and replacing ngmin with ngAnnotate in their Gruntfile. Scroll down for information about other tools.

Library (API)

ng-annotate can be used as a library. See ng-annotate.js for further info about options and return value.

var ngAnnotate = require("ng-annotate");
var somePlugin = require("./some/path/some-plugin");
var res = ngAnnotate(src, {
    add: true,
    plugin: [somePlugin],
    rename: [{from: "generalname", to: "uniquename"}, {from: "alpha", to: "beta"}],
    sourcemap: { inline: false, inFile: "source.js", sourceRoot: "/path/to/source/root" }
var errorstringArray = res.errors;
var transformedSource = res.src;
var transformedSourceMap =;

Module stats last updated: 2018-01-06 15:00:08

Disclaimer: Some data on this page may have been gathered from the authors GitHub respository. If you see any mistakes or outdated information please let us know. Thanks!