tldr; This style-guide is aimed at developers new to Angular

Guidelines

define named functions for each component

Declare named functions for controllers and other components.

angular
  .module('app', [])
  .controller('MainController', function MainController () {

  });

Better:

angular
  .module('app', [])
  .controller('MainController', MainController);


function MainController () {

}

Use dot chaining to build the app rather than repetition of an app variable

In general multi-line dot-chaining is more prone to error, but since we're also avoiding in-line call-backs, the issue should be greatly reduced and overall readability should remain high. This also follows what other style-guides suggest.

var app = angular.module('app', []);
app.controller('MainController', function() {
});

Better:

angular
  .module('app', [])
  .controller('MainController', MainController);

Naming

Suffix should identify the type of module.

Use mapController rather than map. Use phoneService rather than phone

Use UpperCamelCase for controllers, directives, etc.

Some style guides use UpperCamelCase such as DoAwesomeController. This is primarily in preparation for ES6 and classes. While not absolutely necessary, being consistent about this keeps it clear.

function libraryController() { }
function authorDirective() { }

Better:

function LibraryController() { }
function AuthorDirective() { }

use long-form names for controllers and other components

Use mapController not mapCtrl.

Filenames identify component separated by .

The syntax should be {feature}.{component}.js or logger.service.js, library.controller.js.

When working with custom directives

Use these guidelines when introducing and working with directives.

Directives not controllers should manipulate the DOM.

In general DOM manipulations should be done in directives not controllers or services. This excludes built-ins such as ngShow, ngHide, angular animations and templates. CSS and animations can also be used independently.

code from

Don't in-line functions in directives

Don't ng-* prefix directives.

This could conflict with newer versions.

Custom directive elements should not be prefixed with data-, data- only applies to attributes

When working with factories and services

Use these guidelines when introducing factories and services.

Factories vs. Services

Use Services. Services and Factories are exceedingly similar and the differences are very tricky. We don't need to teach both. Services are closer to the way we teach controllers and should therefore be easier for developers. They also look similar to the way we teach constructors. 🌻

This does not conform with John Papa's styleguide. which recommends Factories over Services, but Services are more similar to our controller style. Just pick one and stay consistent!

// factory
function someFactory(){
  var dataObj = {};
  dataObj.doSomething = function(){
	//...
  }
  return dataObj;
}

Better:

// service
function someService() {
  this.doSomething = function(){
	//…
  }
}

Do not call Factories services or Services factories

Calling a Factory a Service or naming it someService is confusing. The difference between the two is already quite confusing without mixing up the terminology.

When introducing minification

Use these rules when working with MEAN or Rails+Angular stacks or anywhere else where you might encounter minification. They can be introduced after developers have gained some familiarity with Angular.

Use $inject vs. inline annotation for dependency injection

Use $inject vs. inline annotation.

This has better readability and lower likelihood of syntax errors. Try to keep the $inject call directly above the function it refers to. You can also align the functions parameters with the injected strings to make this more obvious.

angular
  .module('app')
  .controller('PhoneController', ['$location', '$routeParams', PhoneController]);

function PhoneController($location, $routeParams) {...}

Better:

angular
  .module('app')
  .controller('PhoneController', PhoneController);

PhoneController.$inject = ['$location', '$routeParams'];
function PhoneController($location, $routeParams) {...}

Or (if you're OCD):

// aligned
PhoneController.$inject = ['$location', '$routeParams'];
function PhoneController(   $location,   $routeParams ) {...}

For a comparison see the official angular tutorial

Consider using ng-strict-di with $inject

If you're following the above use of $inject ng-annotate is unnecessary. However, you should consider using ng-strict-di to alert you to missing annotations. Reference

Better:

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