This commit introduces the setClassMetadata() private function, which
adds metadata to a type in a way that can be accessed via Angular's
ReflectionCapabilities. Currently, it writes to static fields as if
the metadata being added was downleveled from decorators by tsickle.
The plan is for ngtsc to emit code which calls this function, passing
metadata on to the runtime for testing purposes. Calls to this function
would then be tree-shaken away for production bundles.
Testing strategy: proper operation of this function will be an integral
part of TestBed metadata overriding. Angular core tests will fail if this
is broken.
PR Close#26860
Uglify and other tree-shakers attempt to determine if the invocation
of a function is side-effectful, and remove it if so (and the result
is unused). A /*@__PURE__*/ annotation on the call site can be used
to hint to the optimizer that the invocation has no side effects and
is safe to tree-shake away.
This commit adds a 'pure' flag to the output AST function call node,
which can be used to signal to downstream emitters that a pure
annotation should be added. It also modifies ngtsc's emitter to
emit an Uglify pure annotation when this flag is set.
Testing strategy: this will be tested via its consumers, by asserting
that pure functions are translated with the correct comment.
PR Close#26860
Template type-checking will make use of expression and statement
translation as well as the ImportManager, so this code needs to
live in a separate build target which can be depended on by both
the main ngtsc transform as well as the template type-checking
mechanism. This refactor introduces a separate build target
for that code.
PR Close#26203
