Previously the `ProgramBasedEntryPointFinder` was parsing all the entry-points referenced by the program for dependencies even if all the entry-points had been processed already. Now this entry-point finder will re-use the `EntryPointManifest` to load the entry-point dependencies when possible which avoids having to parse them all again, on every invocation of ngcc. Previously the `EntryPointManifest` was only used in the `DirectoryWalkerEntryPointFinder`, which also contained the logic for computing the contents of the manifest. This logic has been factored out into an `EntryPointCollector` class. Both the `ProgramBasedEntryPointFinder` and `DirectoryWalkerEntryPointFinder` now use the `EntryPointManifest` and the `EntryPointCollector`. The result of this change is that there is a small cost on the first run of ngcc to compute and store the manifest - the processing takes 102% of the processing time before this PR. But on subsequent runs there is a significant benefit on subsequent runs - the processing takes around 50% of the processing time before this PR. PR Close #37665
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