In Ivy, Angular decorators are compiled into static fields that are
inserted into a class declaration in a TypeScript transform. When
targeting Closure compiler such fields need to be annotated with
`@nocollapse` to prevent them from being lifted from a static field into
a variable, as that would prevent the Ivy runtime from being able to
find the compiled definitions.
Previously, there was a bug in TypeScript where synthetic comments added
in a transform would not be emitted at all, so as a workaround a global
regex-replace was done in the emit's `writeFile` callback that would add
the `@nocollapse` annotation to all static Ivy definition fields. This
approach is no longer possible when ngtsc is running as TypeScript
plugin, as a plugin cannot control emit behavior.
The workaround is no longer necessary, as synthetic comments are now
properly emitted, likely as of
https://github.com/microsoft/TypeScript/pull/22141 which has been
released with TypeScript 2.8.
This change is required for running ngtsc as TypeScript plugin in
Bazel's `ts_library` rule, to move away from the custom `ngc_wrapped`
approach.
Resolves FW-1952
PR Close#35932
This commit bundles 3 important changes, with the goal of enabling tree-shaking
of services which are never injected. Ordinarily, this tree-shaking is prevented
by the existence of a hard dependency on the service by the module in which it
is declared.
Firstly, @Injectable() is modified to accept a 'scope' parameter, which points
to an @NgModule(). This reverses the dependency edge, permitting the module to
not depend on the service which it "provides".
Secondly, the runtime is modified to understand the new relationship created
above. When a module receives a request to inject a token, and cannot find that
token in its list of providers, it will then look at the token for a special
ngInjectableDef field which indicates which module the token is scoped to. If
that module happens to be in the injector, it will behave as if the token
itself was in the injector to begin with.
Thirdly, the compiler is modified to read the @Injectable() metadata and to
generate the special ngInjectableDef field as part of TS compilation, using the
PartialModules system.
Additionally, this commit adds several unit and integration tests of various
flavors to test this change.
PR Close#22005
The "enableIvy" compiler option is the initial implementation
of the Render3 (or Ivy) code generation. This commit enables
generation generating "Hello, World" (example in the test)
but not much else. It is currenly only useful for internal Ivy
testing as Ivy is in development.
PR Close#21427
