title: Failed: Template parse errors: 'app-header' is not a known element
body: <pre><code>homepage.module.ts
  
  import { NgModule, CUSTOM_ELEMENTS_SCHEMA } from "@angular/core";
  import { CommonModule } from "@angular/common";
  import { HomepageComponent } from "./homepage.component";
  import { SharedModule } from "../shared/shared.module";
  
  
  @NgModule({
    declarations: [HomepageComponent],
    imports: [
      CommonModule,
      SharedModule
    ],
    exports: [HomepageComponent],
    providers: [],
    schemas: [CUSTOM_ELEMENTS_SCHEMA]
  })
  export class HomepageModule {}
  
  
  shared-module.ts
  
  import { NgModule, CUSTOM_ELEMENTS_SCHEMA } from "@angular/core";
  import { CommonModule } from "@angular/common";
  import { HeaderComponent } from "./header/header.component";
  @NgModule({
    declarations: [
      HeaderComponent,
    ],
    imports: [
      CommonModule,
    ],
    exports: [
      HeaderComponent,
    ],
    schemas: [CUSTOM_ELEMENTS_SCHEMA]
  })
  export class SharedModule {}
  
  
  homepage.component.html
  
  &lt;app-header (toggleSideBarForMe)="sideBarToggler($event)"&gt;&lt;/app-header&gt;
  
  
  app.module.ts
  
  import { HomepageModule } from "./homepage/homepage.module";
  @NgModule({
    declarations: [AppComponent],
    imports: [
      HomepageModule,
      ],
    providers: [],
    bootstrap: [AppComponent]
  })
  export class AppModule {}
  </code></pre>
  
  <p>while running karma , i am getting the errors . : 
  Failed: Template parse errors:
  'app-header' is not a known element:
  1. If 'app-header' is an Angular component, then verify that it is part of this module.
  2. If 'app-header' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message. ("[ERROR ->]</p>
  
  <p>Do i need to add anything in the homepage.component.spec file ? </p>