The compiler needs to track the dependencies of a component, including any
NgModules which happen to be present in a component's scope. If an upstream
NgModule changes, any downstream components need to have their templates
re-compiled and re-typechecked.
Previously, the compiler handled this well for the A -> B -> C case where
module A imports module B which re-exports module C. However, it fell apart
in the A -> B -> C -> D case, because previously tracking focused on changes
to components/directives in the scope, and not NgModules specifically.
This commit introduces logic to track which NgModules contributed to a given
scope, and treat them as dependencies of any components within.
This logic also contains a bug, which is intentional for now. It
purposefully does not track transitive dependencies of the NgModules which
contribute to a scope. If it did, using the current dependency system, this
would treat all components and directives (even those not exported into the
scope) as dependencies, causing a major performance bottleneck. Only those
dependencies which contributed to the module's export scope should be
considered, but the current system is incapable of making this distinction.
This will be fixed at a later date.
PR Close#36211
bab90a7709