Switches the repository to TypeScript 4.3 and the latest version of tslib. This involves updating the peer dependency ranges on `typescript` for the compiler CLI and for the Bazel package. Tests for new TypeScript features have been added to ensure compatibility with Angular's ngtsc compiler. PR Close #42022
Angular Compatibility Compiler (ngcc)
This compiler will convert node_modules compiled with ngc, into node_modules which
appear to have been compiled with ngtsc.
This conversion will allow such "legacy" packages to be used by the Ivy rendering engine.
Building
The project is built using Bazel:
yarn bazel build //packages/compiler-cli/ngcc
Unit Testing
The unit tests are built and run using Bazel:
yarn bazel test //packages/compiler-cli/ngcc/test
Integration Testing
There are tests that check the behavior of the overall executable:
yarn bazel test //packages/compiler-cli/ngcc/test:integration