In ngcc's migration system, synthetic decorators can be injected into a compilation to ensure that certain classes are compiled with Angular logic, where the original library code did not include the necessary decorators. Prior to this change, synthesized decorators would have a fake AST structure as associated node and a made-up identifier. In theory, this may introduce issues downstream: 1) a decorator's node is used for diagnostics, so it must have position information. Having fake AST nodes without a position is therefore a problem. Note that this is currently not a problem in practice, as injected synthesized decorators would not produce any diagnostics. 2) the decorator's identifier should refer to an imported symbol. Therefore, it is required that the symbol is actually imported. Moreover, bundle formats such as UMD and CommonJS use namespaces for imports, so a bare `ts.Identifier` would not be suitable to use as identifier. This was also not a problem in practice, as the identifier is only used in the `setClassMetadata` generated code, which is omitted for synthetically injected decorators. To remedy these potential issues, this commit makes a decorator's identifier optional and switches its node over from a fake AST structure to the class' name. PR Close #33362
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