refactor(select): simplify option sync and more robust unit tests

src/cdk/overlay/position/connected-position-strategy.spec.ts

@@ -328,6 +328,8 @@ describe('ConnectedPositionStrategy', () => {
 
       it('should allow for the fallback positions to specify their own offsets', () => {
         originElement.style.bottom = '0';
+        originElement.style.left = '50%';
+        originElement.style.position = 'fixed';
         originRect = originElement.getBoundingClientRect();
         strategy = positionBuilder
           .connectedTo(

src/lib/core/option/option.spec.ts

@@ -29,7 +29,7 @@ describe('MatOption component', () => {
     });
 
     it('should show ripples by default', () => {
-      expect(optionInstance.disableRipple).toBe(false, 'Expected ripples to be enabled by default');
+      expect(optionInstance.disableRipple).toBeFalsy('Expected ripples to be enabled by default');
       expect(optionNativeElement.querySelectorAll('.mat-ripple-element').length)
         .toBe(0, 'Expected no ripples to show up initially');
 
@@ -54,20 +54,6 @@ describe('MatOption component', () => {
         .toBe(0, 'Expected no ripples to show up after click on a disabled option.');
     });
 
-    it('should not show ripples if the ripples are disabled using disableRipple', () => {
-      expect(optionNativeElement.querySelectorAll('.mat-ripple-element').length)
-        .toBe(0, 'Expected no ripples to show up initially');
-
-      optionInstance.disableRipple = true;
-      fixture.detectChanges();
-
-      dispatchFakeEvent(optionNativeElement, 'mousedown');
-      dispatchFakeEvent(optionNativeElement, 'mouseup');
-
-      expect(optionNativeElement.querySelectorAll('.mat-ripple-element').length)
-        .toBe(0, 'Expected no ripples to show up after click when ripples are disabled.');
-    });
-
   });
 
 });

src/lib/core/option/option.ts

@@ -19,6 +19,8 @@ import {
   Output,
   QueryList,
   ViewEncapsulation,
+  InjectionToken,
+  Inject,
 } from '@angular/core';
 import {MatOptgroup} from './optgroup';
 
@@ -33,6 +35,22 @@ export class MatOptionSelectionChange {
   constructor(public source: MatOption, public isUserInput = false) { }
 }
 
+/**
+ * Describes a parent component that manages a list of options.
+ * Contains properties that the options can inherit.
+ * @docs-private
+ */
+export interface MatOptionParentComponent {
+  disableRipple?: boolean;
+  multiple?: boolean;
+}
+
+/**
+ * Injection token used to provide the parent component to options.
+ */
+export const MAT_OPTION_PARENT_COMPONENT =
+    new InjectionToken<MatOptionParentComponent>('MAT_OPTION_PARENT_COMPONENT');
+
 /**
  * Single option inside of a `<mat-select>` element.
  */
@@ -60,24 +78,13 @@ export class MatOptionSelectionChange {
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class MatOption {
-  private _selected: boolean = false;
-  private _active: boolean = false;
-  private _multiple: boolean = false;
-  private _disableRipple: boolean = false;
-
-  /** Whether the option is disabled.  */
-  private _disabled: boolean = false;
-
-  private _id: string = `mat-option-${_uniqueIdCounter++}`;
+  private _selected = false;
+  private _active = false;
+  private _disabled = false;
+  private _id = `mat-option-${_uniqueIdCounter++}`;
 
   /** Whether the wrapping component is in multiple selection mode. */
-  get multiple() { return this._multiple; }
-  set multiple(value: boolean) {
-    if (value !== this._multiple) {
-      this._multiple = value;
-      this._changeDetectorRef.markForCheck();
-    }
-  }
+  get multiple() { return this._parent && this._parent.multiple; }
 
   /** The unique ID of the option. */
   get id(): string { return this._id; }
@@ -94,18 +101,15 @@ export class MatOption {
   set disabled(value: any) { this._disabled = coerceBooleanProperty(value); }
 
   /** Whether ripples for the option are disabled. */
-  get disableRipple() { return this._disableRipple; }
-  set disableRipple(value: boolean) {
-    this._disableRipple = value;
-    this._changeDetectorRef.markForCheck();
-  }
+  get disableRipple() { return this._parent && this._parent.disableRipple; }
 
   /** Event emitted when the option is selected or deselected. */
   @Output() onSelectionChange = new EventEmitter<MatOptionSelectionChange>();
 
   constructor(
     private _element: ElementRef,
     private _changeDetectorRef: ChangeDetectorRef,
+    @Optional() @Inject(MAT_OPTION_PARENT_COMPONENT) private _parent: MatOptionParentComponent,
     @Optional() public readonly group: MatOptgroup) {}
 
   /**