Fix test exceptions on IE.

crisbeto · crisbeto · commit fa3f5365d405 · 2017-01-27T22:23:52.000+01:00
diff --git a/src/lib/dialog/dialog-container.ts b/src/lib/dialog/dialog-container.ts
@@ -59,7 +59,7 @@ export class MdDialogContainer extends BasePortalHost implements OnDestroy {
   @ViewChild(FocusTrap) _focusTrap: FocusTrap;
 
   /** Element that was focused before the dialog was opened. Save this to restore upon close. */
-  private _elementFocusedBeforeDialogWasOpened: Element = null;
+  private _elementFocusedBeforeDialogWasOpened: HTMLElement = null;
 
   /** The dialog configuration. */
   dialogConfig: MdDialogConfig;
@@ -89,7 +89,7 @@ export class MdDialogContainer extends BasePortalHost implements OnDestroy {
     // ready in instances where change detection has to run first. To deal with this, we simply
     // wait for the microtask queue to be empty.
     this._ngZone.onMicrotaskEmpty.first().subscribe(() => {
-      this._elementFocusedBeforeDialogWasOpened = document.activeElement;
+      this._elementFocusedBeforeDialogWasOpened = document.activeElement as HTMLElement;
       this._focusTrap.focusFirstTabbableElement();
     });
 
@@ -106,7 +106,14 @@ export class MdDialogContainer extends BasePortalHost implements OnDestroy {
     // the dialog was opened. Wait for the DOM to finish settling before changing the focus so
     // that it doesn't end up back on the <body>.
     this._ngZone.onMicrotaskEmpty.first().subscribe(() => {
-      (this._elementFocusedBeforeDialogWasOpened as HTMLElement).focus();
+      let toFocus = this._elementFocusedBeforeDialogWasOpened;
+
+      // We need to check whether the focus method exists at all, because IE seems to throw an
+      // exception, even if the element is the document.body.
+      if (toFocus && 'focus' in toFocus) {
+        toFocus.focus();
+      }
+
       this._onAnimationStateChange.complete();
     });
   }
