Add the `strictStandalone` flag to `angularCompilerOptions`. When set to
true, the compiler will require that all declarations of components,
directive, and pipes be standalone. When `standalone: false` is provided,
an error is raised.
Note that until the default value of the standalone flag is flipped, this
does not catch the case where a declaration does not specify a value for
`standalone`.
The default value of the `strictStandalone` flag is `false`.
PR Close#57935
This configures whether or not to preserve whitespace content when extracting messages from Angular templates in the legacy (View Engine) extraction pipeline.
This includes several bug fixes which unfortunately cannot be landed without changing message IDs in a breaking fashion and are necessary to properly trim whitespace. Instead these bug fixes are included only when the new flag is disabled.
PR Close#56507