This release switches you to the new Ivy compiler and run time by default. This is one of the biggest updates to Angular in the past 3 years. It’s recommended to update your application to the final release of Angular 8.
First, update your existing angular project to the latest version of Angular 8, ng update @angular/cli@8 @angular/core@8
You can update now to Angular 9, ng update @angular/cli @angular/core
The key changes with this update,
- Angular 9 now compiles with Ivy by default
- Typescript 3.4 and 3.5 are not supported. Upgrade to Typescript 3.7.
Read more changes here - Angular-updating-to-version-9
The advantages of using the Ivy compiler and runtime,
- Smaller bundle size
- Improved type checking
- Improve build errors
- Improved build times
- Improve debugging and more…
Ivy offers a faster and stronger type safety. Compare to Version 8, this will give you detailed error messages.
Ex: In version 8 with view engine, the compiler error would looks like the following,
In version 9 with Ivy, the same compiler error look like this,
I can feel the pain, how we suffered to locate the error up to Version 8. The new version eases the work and locates the error for us.
The angular team have worked a lot to improve the compiler performance and the improvements are near 40%.
There are a lot more improvements that have been done. You can read the full documentation in Angular.IO.