feat(ivy): exclude declarations from injector imports (#29598)

Prior to this change, a module's imports and exports would be used verbatim
as an injectors' imports. This is detrimental for tree-shaking, as a
module's exports could reference declarations that would then prevent such
declarations from being eligible for tree-shaking.

Since an injector actually only needs NgModule references as its imports,
we may safely filter out any declarations from the list of module exports.
This makes them eligible for tree-shaking once again.

PR Close #29598

packages/compiler-cli/src/ngtsc/annotations/src/ng_module.ts

@@ -14,7 +14,7 @@ import {DefaultImportRecorder, Reference, ReferenceEmitter} from '../../imports'
 import {PartialEvaluator, ResolvedValue} from '../../partial_evaluator';
 import {ClassDeclaration, Decorator, ReflectionHost, reflectObjectLiteral, typeNodeToValueExpr} from '../../reflection';
 import {NgModuleRouteAnalyzer} from '../../routing';
-import {LocalModuleScopeRegistry} from '../../scope';
+import {LocalModuleScopeRegistry, ScopeData} from '../../scope';
 import {AnalysisOutput, CompileResult, DecoratorHandler, DetectResult, HandlerPrecedence, ResolveResult} from '../../transform';
 import {getSourceFile} from '../../util/src/typescript';
 
@@ -27,6 +27,7 @@ export interface NgModuleAnalysis {
   ngInjectorDef: R3InjectorMetadata;
   metadataStmt: Statement|null;
   declarations: Reference<ClassDeclaration>[];
+  exports: Reference<ClassDeclaration>[];
 }
 
 /**
@@ -162,13 +163,13 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
         new LiteralArrayExpr([]);
     const rawProviders = ngModule.has('providers') ? ngModule.get('providers') ! : null;
 
+    // At this point, only add the module's imports as the injectors' imports. Any exported modules
+    // are added during `resolve`, as we need scope information to be able to filter out directives
+    // and pipes from the module exports.
     const injectorImports: WrappedNodeExpr<ts.Expression>[] = [];
     if (ngModule.has('imports')) {
       injectorImports.push(new WrappedNodeExpr(ngModule.get('imports') !));
     }
-    if (ngModule.has('exports')) {
-      injectorImports.push(new WrappedNodeExpr(ngModule.get('exports') !));
-    }
 
     if (this.routeAnalyzer !== null) {
       this.routeAnalyzer.add(node.getSourceFile(), name, rawImports, rawExports, rawProviders);
@@ -180,7 +181,7 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
       deps: getValidConstructorDependencies(
           node, this.reflector, this.defaultImportRecorder, this.isCore),
       providers,
-      imports: new LiteralArrayExpr(injectorImports),
+      imports: injectorImports,
     };
 
     return {
@@ -188,6 +189,7 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
         ngModuleDef,
         ngInjectorDef,
         declarations: declarationRefs,
+        exports: exportRefs,
         metadataStmt: generateSetClassMetadataCall(
             node, this.reflector, this.defaultImportRecorder, this.isCore),
       },
@@ -198,6 +200,18 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
   resolve(node: ClassDeclaration, analysis: NgModuleAnalysis): ResolveResult {
     const scope = this.scopeRegistry.getScopeOfModule(node);
     const diagnostics = this.scopeRegistry.getDiagnosticsOfModule(node) || undefined;
+
+    // Using the scope information, extend the injector's imports using the modules that are
+    // specified as module exports.
+    if (scope !== null) {
+      const context = getSourceFile(node);
+      for (const exportRef of analysis.exports) {
+        if (isNgModule(exportRef.node, scope.compilation)) {
+          analysis.ngInjectorDef.imports.push(this.refEmitter.emit(exportRef, context));
+        }
+      }
+    }
+
     if (scope === null || scope.reexports === null) {
       return {diagnostics};
     } else {
@@ -394,6 +408,11 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
   }
 }
 
+function isNgModule(node: ClassDeclaration, compilation: ScopeData): boolean {
+  return !compilation.directives.some(directive => directive.ref.node === node) &&
+      !compilation.pipes.some(pipe => pipe.ref.node === node);
+}
+
 function isDeclarationReference(ref: any): ref is Reference<ts.Declaration> {
   return ref instanceof Reference &&
       (ts.isClassDeclaration(ref.node) || ts.isFunctionDeclaration(ref.node) ||

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts

@@ -472,6 +472,66 @@ describe('ngtsc behavioral tests', () => {
     expect(jsContents).not.toContain('ɵsetNgModuleScope(TestModule,');
   });
 
+  it('should filter out directives and pipes from module exports in the injector def', () => {
+    env.tsconfig();
+    env.write('test.ts', `
+      import {NgModule} from '@angular/core';
+      import {RouterComp, RouterModule} from '@angular/router';
+      import {Dir, OtherDir, MyPipe, Comp} from './decls';
+
+      @NgModule({
+        declarations: [OtherDir],
+        exports: [OtherDir],
+      })
+      export class OtherModule {}
+      
+      const EXPORTS = [Dir, MyPipe, Comp, OtherModule, OtherDir, RouterModule, RouterComp];
+
+      @NgModule({
+        declarations: [Dir, MyPipe, Comp],
+        imports: [OtherModule, RouterModule.forRoot()],
+        exports: [EXPORTS],
+      })
+      export class TestModule {}
+    `);
+    env.write(`decls.ts`, `
+      import {Component, Directive, Pipe} from '@angular/core';
+
+      @Directive({selector: '[dir]'})
+      export class Dir {}
+
+      @Directive({selector: '[other]'})
+      export class OtherDir {}
+
+      @Pipe({name:'pipe'})
+      export class MyPipe {}
+
+      @Component({selector: 'test', template: ''})
+      export class Comp {}
+    `);
+    env.write('node_modules/@angular/router/index.d.ts', `
+      import {ɵComponentDefWithMeta, ModuleWithProviders, ɵNgModuleDefWithMeta} from '@angular/core';
+
+      export declare class RouterComp {
+        static ngComponentDef: ɵComponentDefWithMeta<RouterComp, "lib-cmp", never, {}, {}, never>
+      }
+
+      declare class RouterModule {
+        static forRoot(): ModuleWithProviders<RouterModule>;
+        static ngModuleDef: ɵNgModuleDefWithMeta<RouterModule, [typeof RouterComp], never, [typeof RouterComp]>;
+      }
+    `);
+
+    env.driveMain();
+
+    const jsContents = env.getContents('test.js');
+    expect(jsContents)
+        .toContain(
+            'i0.defineInjector({ factory: function TestModule_Factory(t) ' +
+            '{ return new (t || TestModule)(); }, providers: [], ' +
+            'imports: [[OtherModule, RouterModule.forRoot()],\n            OtherModule,\n            RouterModule] });');
+  });
+
   it('should compile NgModules with services without errors', () => {
     env.tsconfig();
     env.write('test.ts', `