Angular 5.1.0 is here!

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This is a fairly small release, with some bugfixes but not a lot of features.

Let’s see what 5.1 has in stock for us!


The registerLocaleData method now has an optional parameter to set the locale id. This allows to use a custom locale id or locales that Angular does not support. You can now do something like:

registerLocaleData(localeFr, 'fr-ZZ');

and the french locale data will be available for the (fake) locale id fr-ZZ.

Service worker

The @angular/service-worker package evolves a little, with the possibility to register the ServiceWorkerModule without crashing the application even if the Service Worker API is not supported by the browser. The register method has now also a new option to enable the service worker or not. Previously you would have registered your service worker like this:

providers: [
  environment.production ? ServiceWorkerModule.register('/ngsw-worker.js') : [],
  // ...

which would have made the Service Worker services like SwUpdate only available to dependency injection in production. That was forcing us to use a trick like Optional to not crash the application in development:

constructor(@Optional() private swUpdate: SwUpdate) {
  // test if swUpdate is not null

With 5.1, we can do better:

providers: [
  ServiceWorkerModule.register('/ngsw-worker.js', { enabled: environment.production }),
  // ...

With this new enabled option, the services will always be available to dependency injection, making the Optional trick no longer necessary. The services like SwUpdate now also has an isEnabled field to know if they are enabled or not:

constructor(private swUpdate: SwUpdate) {
  if (swUpdate.isEnabled) {
    // ...


It’s worth noting that behind the scenes, some work has been done to enable AoT unit testing. Currently units test are run using the JiT compiler. But as you may know, the Angular team is working to make this JiT compiler obsolete. It’s been recommended for a long time to use the AoT mode in production, and, starting with Angular 5.0, it’s no longer necessary to use JiT even in development as AoT has become faster (even it’s still slower than JiT right now). The last place where JiT is required is for unit testing. That should no longer be the case soon, as some key pieces are falling into place in the framework.

Another interesting point for the compiler: the error messages should now be clearer (especially when you make a mistake in a decorator)!

Angular now also officially supports TypeScript 2.5.x.

That’s all for this small release!

All our materials (ebook, online training (Pro Pack) and training) are up-to-date with these changes if you want to learn more!