title: Can't bind to 'matRowDefColumns' since it isn't a known property of 'mat-row'
body: <p>I am testing an Angular 7 component which uses <code>mat-table</code>, and I have defined a mock module, which declares and exports a mock <code>mat-row</code> component as such:</p>
  
  <pre><code>@Component({selector: 'mat-row', template: ''}) export class StubMatRowComponent {
    @Input() public matRowDefColumns: string[];
  }
  </code></pre>
  
  <p>The usage in the template is this:</p>
  
  <pre><code>&lt;mat-row *matRowDef="let foo; columns: displayedColumns;"&gt;&lt;/mat-row&gt;
  </code></pre>
  
  <p>With this syntax, the error I get is "Can't bind to 'matRowDefColumns' since it isn't a known property of 'mat-row'."</p>
  
  <p>If I didn't need <code>foo</code>, I could write this as follows, which would work:</p>
  
  <pre><code>&lt;mat-row matRowDef="displayedColumns"&gt;&lt;/mat-row&gt;
  </code></pre>
  
  <p>Does anyone know how I can get my mock to work using template syntax?</p>
  
  <p>As a side note, obviously an alternative is rather than importing my mock module, I could import the real thing, but just as obviously, for testing purposes I prefer mocks rather than full integrations.</p>