feat: add LazyModuleFactory

npm/ng-packs/packages/core/src/lib/tests/factory-utils.spec.ts

@@ -0,0 +1,38 @@
+import { Injector, ModuleWithProviders, NgModule } from '@angular/core';
+import { TestBed } from '@angular/core/testing';
+import { LazyModuleFactory } from '../utils/factory-utils';
+
+@NgModule()
+class Module {
+  static forChild(): ModuleWithProviders<Module> {
+    return {
+      ngModule: Module,
+      providers: [{ provide: 'foo', useValue: 'bar' }],
+    };
+  }
+}
+
+describe('LazyModuleFactory', () => {
+  const factory = new LazyModuleFactory(Module.forChild());
+
+  describe('#moduleType', () => {
+    it('should return the ngModule property of given ModuleWithProviders', () => {
+      expect(factory.moduleType).toBe(Module);
+    });
+  });
+
+  describe('#create', () => {
+    it('should return an instance of NgModuleRef_', () => {
+      TestBed.configureTestingModule({});
+
+      const injector = TestBed.inject(Injector);
+      const moduleRef = factory.create(injector);
+
+      expect('componentFactoryResolver' in moduleRef).toBe(true);
+      expect('destroy' in moduleRef).toBe(true);
+      expect('injector' in moduleRef).toBe(true);
+      expect('instance' in moduleRef).toBe(true);
+      expect('onDestroy' in moduleRef).toBe(true);
+    });
+  });
+});

npm/ng-packs/packages/core/src/lib/utils/factory-utils.ts

@@ -0,0 +1,31 @@
+import {
+  Compiler,
+  Injector,
+  ModuleWithProviders,
+  NgModuleFactory,
+  NgModuleRef,
+  StaticProvider,
+  Type,
+} from '@angular/core';
+
+export class LazyModuleFactory<T> extends NgModuleFactory<T> {
+  get moduleType(): Type<T> {
+    return this.moduleWithProviders.ngModule;
+  }
+
+  constructor(private moduleWithProviders: ModuleWithProviders<T>) {
+    super();
+  }
+
+  create(parentInjector: Injector | null): NgModuleRef<T> {
+    const injector = Injector.create({
+      parent: parentInjector,
+      providers: this.moduleWithProviders.providers as StaticProvider[],
+    });
+
+    const compiler = injector.get(Compiler);
+    const factory = compiler.compileModuleSync(this.moduleType);
+
+    return factory.create(injector);
+  }
+}

npm/ng-packs/packages/core/src/lib/utils/index.ts

@@ -1,4 +1,5 @@
 export * from './common-utils';
+export * from './factory-utils';
 export * from './form-utils';
 export * from './generator-utils';
 export * from './initial-utils';