From 5d437ea861bbd39f967b018578d4e00357be4b81 Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@users.noreply.github.com>
Date: Tue, 15 Aug 2017 23:48:08 +0200
Subject: [PATCH] refactor: remove usages of `if in` checks (#6436)

This is something that came up in https://github.com/angular/material2/pull/2907#discussion_r130968388. We shouldn't be using the `if ('someString' in obj)` checks, because they can be broken by minifiers that rename class members.
---
 src/lib/core/option/option.ts             | 2 +-
 src/lib/datepicker/datepicker.ts          | 4 +++-
 src/lib/dialog/dialog-container.ts        | 2 +-
 src/lib/slide-toggle/slide-toggle.spec.ts | 2 +-
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/lib/core/option/option.ts b/src/lib/core/option/option.ts
index 09a88598f47..aeb02e12d77 100644
--- a/src/lib/core/option/option.ts
+++ b/src/lib/core/option/option.ts
@@ -145,7 +145,7 @@ export class MdOption {
   focus(): void {
     const element = this._getHostElement();
 
-    if ('focus' in element) {
+    if (typeof element.focus === 'function') {
       element.focus();
     }
   }
diff --git a/src/lib/datepicker/datepicker.ts b/src/lib/datepicker/datepicker.ts
index 55a8c4a0219..7e91ed6c755 100644
--- a/src/lib/datepicker/datepicker.ts
+++ b/src/lib/datepicker/datepicker.ts
@@ -278,7 +278,9 @@ export class MdDatepicker<D> implements OnDestroy {
     if (this._calendarPortal && this._calendarPortal.isAttached) {
       this._calendarPortal.detach();
     }
-    if (this._focusedElementBeforeOpen && 'focus' in this._focusedElementBeforeOpen) {
+    if (this._focusedElementBeforeOpen &&
+      typeof this._focusedElementBeforeOpen.focus === 'function') {
+
       this._focusedElementBeforeOpen.focus();
       this._focusedElementBeforeOpen = null;
     }
diff --git a/src/lib/dialog/dialog-container.ts b/src/lib/dialog/dialog-container.ts
index 816b4ce11ea..235f46cd717 100644
--- a/src/lib/dialog/dialog-container.ts
+++ b/src/lib/dialog/dialog-container.ts
@@ -150,7 +150,7 @@ export class MdDialogContainer extends BasePortalHost {
     const toFocus = this._elementFocusedBeforeDialogWasOpened;
 
     // We need the extra check, because IE can set the `activeElement` to null in some cases.
-    if (toFocus && 'focus' in toFocus) {
+    if (toFocus && typeof toFocus.focus === 'function') {
       toFocus.focus();
     }
 
diff --git a/src/lib/slide-toggle/slide-toggle.spec.ts b/src/lib/slide-toggle/slide-toggle.spec.ts
index 981aaa5c27a..eda08374dc1 100644
--- a/src/lib/slide-toggle/slide-toggle.spec.ts
+++ b/src/lib/slide-toggle/slide-toggle.spec.ts
@@ -699,7 +699,7 @@ describe('MdSlideToggle with forms', () => {
     }));
 
     it('should prevent the form from submit when being required', () => {
-      if ('reportValidity' in inputElement === false) {
+      if (typeof (inputElement as any).reportValidity === 'undefined') {
         // If the browser does not report the validity then the tests will break.
         // e.g Safari 8 on Mobile.
         return;