ANGULARJS
CODING TEST.

An async callback mutates $scope but the view doesn't update. Fix it.

AngularJS only re-renders when a digest runs. Setting $scope from outside Angular (setTimeout, jQuery event, third-party SDK) leaves the digest unaware. Wrap the mutation in $scope.$apply() — or use $timeout / $http which schedule a digest for you.

setTimeout(function () {
  $scope.$apply(function () {
    $scope.user = data;
  });
}, 500);

What's the difference between $watch, $watchCollection, and $watchGroup?

$watch does reference equality (or deep with a third arg). $watchCollection is a shallow check on array / object keys — cheaper than a deep watch when you only care about add/remove. $watchGroup fires once per digest for any change across a list of expressions, with the new + old arrays.

Difference between compile, controller, pre-link, and post-link?

Order: compile (template manipulation, runs once per template) → controller (DI-injected, runs per instance) → pre-link (parent before children) → post-link (children before parent — the default 'link' you write). Mutate DOM in post-link; transform the template in compile.

Scope: true vs scope: {} vs scope: false — when do you pick which?

false = share parent scope (cheap, but reads/writes pollute). true = new child scope that prototypically inherits (good for widgets that read parent state). {} = isolate scope (best for reusable components — explicit bindings with @, =, &).

factory vs service vs provider?

factory: returns whatever you return — usually an object literal. service: NEW's your constructor (this. members become the API). provider: configurable at module.config() time via a $get() — use only when you need config-phase setup like an API base URL.

Why does minification break my AngularJS app?

AngularJS infers dependencies from parameter names. Minifiers rename them to a, b, c. Use the inline array annotation: app.controller('X', ['$scope', '$http', function ($scope, $http) { ... }]) or ng-annotate to add it automatically.

How do you cancel an in-flight $http request?

Pass a timeout that's a $q.defer().promise; resolve the deferred to abort. New code can also pass an AbortController-style canceller via the request config timeout property.

var canceller = $q.defer();
$http.get('/api/search', { timeout: canceller.promise });
// later
canceller.resolve();

What's the right way to attach a global auth header to every request?

Write an $http interceptor with a request function that adds the header, register it in $httpProvider.interceptors during config phase. Don't monkey-patch $http or set defaults from a controller — interceptors are the only place that runs for every call.

ngRoute vs ui-router — which would you pick?

ui-router for any non-trivial app — it supports nested + named views, state-based navigation, and proper resolve cascades. ngRoute is fine for a single-level URL → template app, nothing more.

What does resolve do in a route definition?

resolve returns a map of promises that must settle before the route's controller instantiates. Use it to preload required data so the view never flashes empty; the resolved values are injected into the controller by name.