In Ivy, template type-checking has 3 modes: basic, full, and strict. The
primary difference between basic and full modes is that basic mode only
checks the top-level template, whereas full mode descends into nested
templates (embedded views like ngIfs and ngFors). Ivy applies this approach
to all of its template type-checking, including the DOM schema checks which
validate whether an element is a valid component/directive or not.
View Engine has both the basic and the full mode, with the same distinction.
However in View Engine, DOM schema checks happen for the full template even
in the basic mode.
Ivy's behavior here is technically a "fix" as it does not make sense for
some checks to apply to the full template and others only to the top-level
view. However, since g3 relies exclusively on the basic mode of checking and
developers there are used to DOM checks applying throughout their template,
this commit re-enables the nested schema checks even in basic mode only in
g3. This is done by enabling the checks only when Closure Compiler
annotations are requested.
Outside of g3, it's recommended that applications use at least the full mode
of checking (controlled by the `fullTemplateTypeCheck` flag), and ideally
the strict mode (`strictTemplates`).
PR Close#38943
40975e06c6