JoostK 3858b26211 refactor(ivy): mark synthetic decorators explicitly (#33362)
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
2019-10-25 09:16:49 -07:00
..

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