The Angular 9.1 release adds support for TypeScript 3.8 and reduces the time it takes to build an Angular application.
TypeScript 3.8 was a significant improvement to the language, adding several new ES2020 features like private class fields and top-level await, as well as type-only imports and exports. Many projects have recently released updates to support these advances in TypeScript.
With Angular 9.0, the long-awaited Ivy engine was switched to the default compilation and rendering pipeline for Angular applications. To add compatibility with various Angular libraries, Angular provides the ngcc tool. With Angular 9.1, ngcc can now compile packages concurrently rather than the previous limit of sequential compilation.
Angular 9.1 also adds support for defining new Angular components as having CSS block display rather than the default of inline.
Updates to Angular's approach to end-to-end tests now support passing grep and invertGrep options to Protractor, a common approach with other frameworks also supported by Angular.
Angular 9.1 also updates its dependency on TSLint to version 6.1. Developers upgrading their projects from earlier Angular releases should first upgrade to Angular 9.1and then run the following command:
ng update @angular/cli --migrate-only tslint-version-6
The update in TSLint was a common question in the community, who were expecting a switch from TSLint to the TypeScript version of ESLint as TSLint was deprecated in early 2019. The Angular team is already working on version 10, which will include switching from TSLint to ESLint.
Angular is open-source software available under the MIT license via the Angular GitHub repository. Feedback and contributions are encouraged via the Angular contribution guidelines and code of conduct.