Previously, while trying to build an `NgccReflectionHost`'s `privateDtsDeclarationMap`, `computePrivateDtsDeclarationMap()` would try to collect exported declarations from all source files of the program (i.e. without checking whether they were within the target package, as happens for declarations in `.d.ts` files). Most of the time, that would not be a problem, because external packages would be represented as `.d.ts` files in the program. But when an external package had no typings, the JS files would be used instead. As a result, the `ReflectionHost` would try to (unnecessarilly) parse the file in order to extract exported declarations, which in turn would be harmless in most cases. There are certain cases, though, where the `ReflectionHost` would throw an error, because it cannot parse the external package's JS file. This could happen, for example, in `UmdReflectionHost`, which expects the file to contain exactly one statement. See #34544 for more details on a real-world failure. This commit fixes the issue by ensuring that `computePrivateDtsDeclarationMap()` will only collect exported declarations from files within the target package. Jira issue: [FW-1794](https://angular-team.atlassian.net/browse/FW-1794) Fixes #34544 PR Close #34811
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