fix: consistently coerce boolean and number properties to the correct type

src/cdk/accordion/accordion-item.ts

@@ -17,6 +17,7 @@ import {
 } from '@angular/core';
 import {UniqueSelectionDispatcher} from '@angular/cdk/collections';
 import {CdkAccordion} from './accordion';
+import {coerceBooleanProperty} from '@angular/cdk/coercion';
 
 /** Used to generate unique ID for each accordion item. */
 let nextId = 0;
@@ -41,8 +42,10 @@ export class CdkAccordionItem implements OnDestroy {
 
   /** Whether the AccordionItem is expanded. */
   @Input()
-  get expanded(): boolean { return this._expanded; }
-  set expanded(expanded: boolean) {
+  get expanded(): any { return this._expanded; }
+  set expanded(expanded: any) {
+    expanded = coerceBooleanProperty(expanded);
+
     // Only emit events and update the internal value if the value changes.
     if (this._expanded !== expanded) {
       this._expanded = expanded;

src/cdk/coercion/number-property.ts

@@ -7,6 +7,8 @@
  */
 
 /** Coerces a data-bound value (typically a string) to a number. */
+export function coerceNumberProperty(value: any): number;
+export function coerceNumberProperty<D>(value: any, fallback: D): number | D;
 export function coerceNumberProperty(value: any, fallbackValue = 0) {
   // parseFloat(value) handles most of the cases we're interested in (it treats null, empty string,
   // and other non-number values as NaN, where Number just uses 0) but it considers the string

src/lib/datepicker/datepicker.ts

@@ -143,15 +143,22 @@ export class MatDatepicker<D> implements OnDestroy {
    * Whether the calendar UI is in touch mode. In touch mode the calendar opens in a dialog rather
    * than a popup and elements have more padding to allow for bigger touch targets.
    */
-  @Input() touchUi = false;
+  @Input()
+  get touchUi(): boolean {
+    return this._touchUi;
+  }
+  set touchUi(value: boolean) {
+    this._touchUi = coerceBooleanProperty(value);
+  }
+  private _touchUi = false;
 
   /** Whether the datepicker pop-up should be disabled. */
   @Input()
-  get disabled() {
+  get disabled(): boolean {
     return this._disabled === undefined && this._datepickerInput ?
         this._datepickerInput.disabled : !!this._disabled;
   }
-  set disabled(value: any) {
+  set disabled(value: boolean) {
     const newValue = coerceBooleanProperty(value);
 
     if (newValue !== this._disabled) {

src/lib/expansion/expansion-panel.ts

@@ -26,6 +26,7 @@ import {UniqueSelectionDispatcher} from '@angular/cdk/collections';
 import {CanDisable, mixinDisabled} from '@angular/material/core';
 import {Subject} from 'rxjs/Subject';
 import {MatAccordion} from './accordion';
+import {coerceBooleanProperty} from '@angular/cdk/coercion';
 
 /** Workaround for https://github.com/angular/angular/issues/17849 */
 export const _CdkAccordionItem = CdkAccordionItem;
@@ -90,8 +91,16 @@ export const EXPANSION_PANEL_ANIMATION_TIMING = '225ms cubic-bezier(0.4,0.0,0.2,
 })
 export class MatExpansionPanel extends _MatExpansionPanelMixinBase
     implements CanDisable, OnChanges, OnDestroy {
+
   /** Whether the toggle indicator should be hidden. */
-  @Input() hideToggle: boolean = false;
+  @Input()
+  get hideToggle(): boolean {
+    return this._hideToggle;
+  }
+  set hideToggle(value: boolean) {
+    this._hideToggle = coerceBooleanProperty(value);
+  }
+  private _hideToggle = false;
 
   /** Stream that emits for changes in `@Input` properties. */
   _inputChanges = new Subject<SimpleChanges>();

src/lib/menu/menu-directive.ts

@@ -37,6 +37,7 @@ import {throwMatMenuInvalidPositionX, throwMatMenuInvalidPositionY} from './menu
 import {MatMenuItem} from './menu-item';
 import {MatMenuPanel} from './menu-panel';
 import {MenuPositionX, MenuPositionY} from './menu-positions';
+import {coerceBooleanProperty} from '@angular/cdk/coercion';
 
 
 /** Default `mat-menu` options that can be overridden. */
@@ -120,7 +121,14 @@ export class MatMenu implements AfterContentInit, MatMenuPanel, OnDestroy {
   @ContentChildren(MatMenuItem) items: QueryList<MatMenuItem>;
 
   /** Whether the menu should overlap its trigger. */
-  @Input() overlapTrigger = this._defaultOptions.overlapTrigger;
+  @Input()
+  set overlapTrigger(value: boolean) {
+    this._overlapTrigger = coerceBooleanProperty(value);
+  }
+  get overlapTrigger(): boolean {
+    return this._overlapTrigger;
+  }
+  private _overlapTrigger: boolean = this._defaultOptions.overlapTrigger;
 
   /**
    * This method takes classes set on the host mat-menu element and applies them on the

src/lib/slide-toggle/slide-toggle.ts

@@ -124,7 +124,7 @@ export class MatSlideToggle extends _MatSlideToggleMixinBase implements OnDestro
   @Input()
   get checked(): boolean { return this._checked; }
   set checked(value) {
-    this._checked = !!value;
+    this._checked = coerceBooleanProperty(value);
     this._changeDetectorRef.markForCheck();
   }
   /** An event will be dispatched each time the slide-toggle changes its value. */

src/lib/tabs/tab-group.ts

@@ -23,7 +23,7 @@ import {
   ViewChild,
   ViewEncapsulation,
 } from '@angular/core';
-import {coerceBooleanProperty} from '@angular/cdk/coercion';
+import {coerceBooleanProperty, coerceNumberProperty} from '@angular/cdk/coercion';
 import {Subscription} from 'rxjs/Subscription';
 import {MatTab} from './tab';
 import {MatTabHeader} from './tab-header';
@@ -109,7 +109,9 @@ export class MatTabGroup extends _MatTabGroupMixinBase implements AfterContentIn
 
   /** The index of the active tab. */
   @Input()
-  set selectedIndex(value: number | null) { this._indexToSelect = value; }
+  set selectedIndex(value: number | null) {
+    this._indexToSelect = coerceNumberProperty(value, null);
+  }
   get selectedIndex(): number | null { return this._selectedIndex; }
   private _selectedIndex: number | null = null;
 

src/lib/tabs/tab-header.ts

@@ -31,6 +31,7 @@ import {CanDisableRipple, mixinDisableRipple} from '@angular/material/core';
 import {merge} from 'rxjs/observable/merge';
 import {of as observableOf} from 'rxjs/observable/of';
 import {Subscription} from 'rxjs/Subscription';
+import {coerceNumberProperty} from '@angular/cdk/coercion';
 import {MatInkBar} from './ink-bar';
 import {MatTabLabelWrapper} from './tab-label-wrapper';
 import {ViewportRuler} from '@angular/cdk/scrolling';
@@ -120,6 +121,7 @@ export class MatTabHeader extends _MatTabHeaderMixinBase
   @Input()
   get selectedIndex(): number { return this._selectedIndex; }
   set selectedIndex(value: number) {
+    value = coerceNumberProperty(value);
     this._selectedIndexChanged = this._selectedIndex != value;
     this._selectedIndex = value;
     this._focusIndex = value;