Partial mode: NgModule-declared components get no dependencies, so their directives never match #655

Summary

In partial compilation, a component declared in an NgModule (standalone: false) gets no dependencies in ɵɵngDeclareComponent. After linking, App.ɵcmp.directiveDefs is null, so no directive from the NgModule scope matches in its template. Full mode works, because there dependencies is ɵɵgetComponentDepsFactory(App), which is resolved at runtime.

Found while re-checking #623.

Reproduction

// dep.ts
@Directive({selector: '[d]', standalone: false}) export class D {}
@NgModule({declarations: [D], exports: [D]}) export class DepModule {}

// main.ts
import {DepModule} from './dep';
@Component({selector: 'app', template: '<div d></div>', standalone: false}) export class App {}
@NgModule({declarations: [App], imports: [DepModule]}) export class AModule {}

Compiled with compilationMode: 'partial', linked with linkAngularPackageSync, and run with @angular/core 22.2:

Notes

ngtsc builds this list from the NgModule scope, which comes from the whole program. One way to do it one file at a time is to emit something in partial mode that resolves at runtime, as full mode does with ɵɵgetComponentDepsFactory. Angular's linker would also have to accept that output, so this needs a design decision.