refactor: clean out variables that are being assigned to but not being read

Clears out private properties and local variables that are declared and assigned values, but aren't actually being read at any point. This will start being caught by tslint once we update to TS 2.6.

Author: crisbeto

src/cdk/a11y/focus-trap/focus-trap.spec.ts

@@ -76,12 +76,10 @@ describe('FocusTrap', () => {
 
   describe('with bindings', () => {
     let fixture: ComponentFixture<FocusTrapWithBindings>;
-    let focusTrapInstance: FocusTrap;
 
     beforeEach(() => {
       fixture = TestBed.createComponent(FocusTrapWithBindings);
       fixture.detectChanges();
-      focusTrapInstance = fixture.componentInstance.focusTrapDirective.focusTrap;
     });
 
     it('should clean up its anchor sibling elements on destroy', () => {

src/cdk/layout/media-matcher.spec.ts

@@ -5,13 +5,12 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-import {LayoutModule, BreakpointObserver} from './index';
+import {LayoutModule} from './index';
 import {MediaMatcher} from './media-matcher';
 import {async, TestBed, inject} from '@angular/core/testing';
 import {Platform} from '@angular/cdk/platform';
 
 describe('MediaMatcher', () => {
-  let breakpointManager: BreakpointObserver;
   let mediaMatcher: MediaMatcher;
 
   beforeEach(async(() => {
@@ -20,12 +19,9 @@ describe('MediaMatcher', () => {
     });
   }));
 
-  beforeEach(inject(
-    [BreakpointObserver, MediaMatcher],
-    (bm: BreakpointObserver, mm: MediaMatcher) => {
-      breakpointManager = bm;
-      mediaMatcher = mm;
-    }));
+  beforeEach(inject([MediaMatcher], (mm: MediaMatcher) => {
+    mediaMatcher = mm;
+  }));
 
   it('correctly returns a MediaQueryList to check for matches', () => {
     expect(mediaMatcher.matchMedia('(min-width: 1px)').matches).toBeTruthy();

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

@@ -35,9 +35,6 @@ import {OverlayRef} from '../overlay-ref';
  * of the overlay.
  */
 export class ConnectedPositionStrategy implements PositionStrategy {
-  /** The overlay to which this strategy is attached. */
-  private _overlayRef: OverlayRef;
-
   /** Layout direction of the position strategy. */
   private _dir = 'ltr';
 
@@ -100,7 +97,6 @@ export class ConnectedPositionStrategy implements PositionStrategy {
 
   /** Attach this position strategy to an overlay. */
   attach(overlayRef: OverlayRef): void {
-    this._overlayRef = overlayRef;
     this._pane = overlayRef.overlayElement;
     this._resizeSubscription.unsubscribe();
     this._resizeSubscription = this._viewportRuler.change().subscribe(() => this.apply());

src/cdk/tree/tree.ts

@@ -139,9 +139,6 @@ export class CdkTree<T> implements CollectionViewer, OnInit, OnDestroy {
   /** Subject that emits when the component has been destroyed. */
   private _onDestroy = new Subject<void>();
 
-  /** Latest data provided by the data source through the connect interface. */
-  private _data = new Array<T>();
-
   /** Differ used to find the changes in the data provided by the data source. */
   private _dataDiffer: IterableDiffer<T>;
 
@@ -231,8 +228,6 @@ export class CdkTree<T> implements CollectionViewer, OnInit, OnDestroy {
    * clearing the node outlet. Otherwise start listening for new data.
    */
   private _switchDataSource(dataSource: DataSource<T> | Observable<T[]> | T[]) {
-    this._data = new Array<T>();
-
     if (this._dataSource && typeof (this._dataSource as DataSource<T>).disconnect === 'function') {
       (this.dataSource as DataSource<T>).disconnect(this);
     }
@@ -269,10 +264,7 @@ export class CdkTree<T> implements CollectionViewer, OnInit, OnDestroy {
 
     if (dataStream) {
       this._dataSubscription = dataStream.pipe(takeUntil(this._onDestroy))
-        .subscribe(data => {
-          this._data = data;
-          this._renderNodeChanges(data);
-        });
+        .subscribe(data => this._renderNodeChanges(data));
     } else {
       throw getTreeNoValidDataSourceError();
     }

src/lib/autocomplete/autocomplete.spec.ts

@@ -1468,6 +1468,7 @@ describe('MatAutocomplete', () => {
       zone.simulateZoneExit();
 
       expect(spy).toHaveBeenCalledWith(jasmine.any(MatOptionSelectionChange));
+      subscription!.unsubscribe();
     }));
 
   });

src/lib/button-toggle/button-toggle.spec.ts

@@ -81,9 +81,7 @@ describe('MatButtonToggle with forms', () => {
   describe('button toggle group with ngModel and change event', () => {
     let fixture: ComponentFixture<ButtonToggleGroupWithNgModel>;
     let groupDebugElement: DebugElement;
-    let groupNativeElement: HTMLElement;
     let buttonToggleDebugElements: DebugElement[];
-    let buttonToggleNativeElements: HTMLElement[];
     let groupInstance: MatButtonToggleGroup;
     let buttonToggleInstances: MatButtonToggle[];
     let testComponent: ButtonToggleGroupWithNgModel;
@@ -96,13 +94,10 @@ describe('MatButtonToggle with forms', () => {
       testComponent = fixture.debugElement.componentInstance;
 
       groupDebugElement = fixture.debugElement.query(By.directive(MatButtonToggleGroup));
-      groupNativeElement = groupDebugElement.nativeElement;
       groupInstance = groupDebugElement.injector.get<MatButtonToggleGroup>(MatButtonToggleGroup);
       groupNgModel = groupDebugElement.injector.get<NgModel>(NgModel);
 
       buttonToggleDebugElements = fixture.debugElement.queryAll(By.directive(MatButtonToggle));
-      buttonToggleNativeElements =
-        buttonToggleDebugElements.map(debugEl => debugEl.nativeElement);
       buttonToggleInstances = buttonToggleDebugElements.map(debugEl => debugEl.componentInstance);
       buttonToggleLabels = buttonToggleDebugElements.map(
         debugEl => debugEl.query(By.css('label')).nativeElement);
@@ -545,14 +540,11 @@ describe('MatButtonToggle without forms', () => {
     let buttonToggleNativeElement: HTMLElement;
     let buttonToggleLabelElement: HTMLLabelElement;
     let buttonToggleInstance: MatButtonToggle;
-    let testComponent: StandaloneButtonToggle;
 
     beforeEach(async(() => {
       fixture = TestBed.createComponent(StandaloneButtonToggle);
       fixture.detectChanges();
 
-      testComponent = fixture.debugElement.componentInstance;
-
       buttonToggleDebugElement = fixture.debugElement.query(By.directive(MatButtonToggle));
       buttonToggleNativeElement = buttonToggleDebugElement.nativeElement;
       buttonToggleLabelElement = fixture.debugElement.query(By.css('label')).nativeElement;

src/lib/checkbox/checkbox.spec.ts

@@ -748,7 +748,6 @@ describe('MatCheckbox', () => {
     let checkboxNativeElement: HTMLElement;
     let testComponent: CheckboxWithTabIndex;
     let inputElement: HTMLInputElement;
-    let labelElement: HTMLLabelElement;
 
     beforeEach(() => {
       fixture = TestBed.createComponent(CheckboxWithTabIndex);
@@ -758,7 +757,6 @@ describe('MatCheckbox', () => {
       checkboxDebugElement = fixture.debugElement.query(By.directive(MatCheckbox));
       checkboxNativeElement = checkboxDebugElement.nativeElement;
       inputElement = <HTMLInputElement>checkboxNativeElement.querySelector('input');
-      labelElement = <HTMLLabelElement>checkboxNativeElement.querySelector('label');
     });
 
     it('should preserve any given tabIndex', () => {
@@ -940,7 +938,6 @@ describe('MatCheckbox', () => {
 
   describe('without label', () => {
     let testComponent: CheckboxWithoutLabel;
-    let checkboxElement: HTMLElement;
     let checkboxInnerContainer: HTMLElement;
 
     beforeEach(() => {
@@ -949,7 +946,6 @@ describe('MatCheckbox', () => {
       const checkboxDebugEl = fixture.debugElement.query(By.directive(MatCheckbox));
 
       testComponent = fixture.componentInstance;
-      checkboxElement = checkboxDebugEl.nativeElement;
       checkboxInnerContainer = checkboxDebugEl
         .query(By.css('.mat-checkbox-inner-container')).nativeElement;
     });

src/lib/chips/chip-list.spec.ts

@@ -455,15 +455,13 @@ describe('MatChipList', () => {
   });
 
   describe('forms integration', () => {
-    let formField: HTMLElement;
     let nativeChips: HTMLElement[];
 
     describe('single selection', () => {
       beforeEach(() => {
         fixture = TestBed.createComponent(BasicChipList);
         fixture.detectChanges();
 
-        formField = fixture.debugElement.query(By.css('.mat-form-field')).nativeElement;
         nativeChips = fixture.debugElement.queryAll(By.css('mat-chip'))
           .map((chip) => chip.nativeElement);
         chips = fixture.componentInstance.chips;
@@ -627,7 +625,6 @@ describe('MatChipList', () => {
         fixture = TestBed.createComponent(MultiSelectionChipList);
         fixture.detectChanges();
 
-        formField = fixture.debugElement.query(By.css('.mat-form-field')).nativeElement;
         nativeChips = fixture.debugElement.queryAll(By.css('mat-chip'))
           .map((chip) => chip.nativeElement);
         chips = fixture.componentInstance.chips;
@@ -705,14 +702,12 @@ describe('MatChipList', () => {
   });
 
   describe('chip list with chip input', () => {
-    let formField: HTMLElement;
     let nativeChips: HTMLElement[];
 
     beforeEach(() => {
       fixture = TestBed.createComponent(InputChipList);
       fixture.detectChanges();
 
-      formField = fixture.debugElement.query(By.css('.mat-form-field')).nativeElement;
       nativeChips = fixture.debugElement.queryAll(By.css('mat-chip'))
         .map((chip) => chip.nativeElement);
     });

src/lib/chips/chip-list.ts

@@ -389,6 +389,11 @@ export class MatChipList extends _MatChipListMixinBase implements MatFormFieldCo
     if (this._changeSubscription) {
       this._changeSubscription.unsubscribe();
     }
+
+    if (this._chipRemoveSubscription) {
+      this._chipRemoveSubscription.unsubscribe();
+    }
+
     this._dropSubscriptions();
     this.stateChanges.complete();
   }

src/lib/chips/chip.spec.ts

@@ -4,13 +4,12 @@ import {createKeyboardEvent} from '@angular/cdk/testing';
 import {Component, DebugElement} from '@angular/core';
 import {async, ComponentFixture, TestBed} from '@angular/core/testing';
 import {By} from '@angular/platform-browser';
-import {MatChip, MatChipEvent, MatChipList, MatChipSelectionChange, MatChipsModule} from './index';
+import {MatChip, MatChipEvent, MatChipSelectionChange, MatChipsModule} from './index';
 
 
 describe('Chips', () => {
   let fixture: ComponentFixture<any>;
   let chipDebugElement: DebugElement;
-  let chipListNativeElement: HTMLElement;
   let chipNativeElement: HTMLElement;
   let chipInstance: MatChip;
 
@@ -59,7 +58,6 @@ describe('Chips', () => {
       fixture.detectChanges();
 
       chipDebugElement = fixture.debugElement.query(By.directive(MatChip));
-      chipListNativeElement = fixture.debugElement.query(By.directive(MatChipList)).nativeElement;
       chipNativeElement = chipDebugElement.nativeElement;
       chipInstance = chipDebugElement.injector.get(MatChip);
       testComponent = fixture.debugElement.componentInstance;

src/lib/core/ripple/ripple.spec.ts

@@ -543,14 +543,12 @@ describe('MatRipple', () => {
 
   describe('configuring behavior', () => {
     let controller: RippleContainerWithInputBindings;
-    let rippleComponent: MatRipple;
 
     beforeEach(() => {
       fixture = TestBed.createComponent(RippleContainerWithInputBindings);
       fixture.detectChanges();
 
       controller = fixture.debugElement.componentInstance;
-      rippleComponent = controller.ripple;
       rippleTarget = fixture.debugElement.nativeElement.querySelector('[mat-ripple]');
     });
 

src/lib/datepicker/month-view.spec.ts

@@ -262,7 +262,6 @@ describe('MatMonthView', () => {
 
   describe('month view with date filter', () => {
     let fixture: ComponentFixture<MonthViewWithDateFilter>;
-    let testComponent: MonthViewWithDateFilter;
     let monthViewNativeElement: Element;
 
     beforeEach(() => {
@@ -271,7 +270,6 @@ describe('MatMonthView', () => {
 
       let monthViewDebugElement = fixture.debugElement.query(By.directive(MatMonthView));
       monthViewNativeElement = monthViewDebugElement.nativeElement;
-      testComponent = fixture.componentInstance;
     });
 
     it('should disable filtered dates', () => {

src/lib/datepicker/multi-year-view.spec.ts

@@ -225,7 +225,6 @@ describe('MatMultiYearView', () => {
 
   describe('multi year view with date filter', () => {
     let fixture: ComponentFixture<MultiYearViewWithDateFilter>;
-    let testComponent: MultiYearViewWithDateFilter;
     let multiYearViewNativeElement: Element;
 
     beforeEach(() => {
@@ -234,7 +233,6 @@ describe('MatMultiYearView', () => {
 
       const multiYearViewDebugElement = fixture.debugElement.query(By.directive(MatMultiYearView));
       multiYearViewNativeElement = multiYearViewDebugElement.nativeElement;
-      testComponent = fixture.componentInstance;
     });
 
     it('should disablex years with no enabled days', () => {

src/lib/datepicker/year-view.spec.ts

@@ -293,7 +293,6 @@ describe('MatYearView', () => {
 
   describe('year view with date filter', () => {
     let fixture: ComponentFixture<YearViewWithDateFilter>;
-    let testComponent: YearViewWithDateFilter;
     let yearViewNativeElement: Element;
 
     beforeEach(() => {
@@ -302,7 +301,6 @@ describe('MatYearView', () => {
 
       const yearViewDebugElement = fixture.debugElement.query(By.directive(MatYearView));
       yearViewNativeElement = yearViewDebugElement.nativeElement;
-      testComponent = fixture.componentInstance;
     });
 
     it('should disable months with no enabled days', () => {

src/lib/list/list.ts

@@ -109,7 +109,6 @@ export class MatListSubheaderCssMatStyler {}
 })
 export class MatListItem extends _MatListItemMixinBase implements AfterContentInit,
     CanDisableRipple {
-  private _lineSetter: MatLineSetter;
   private _isNavList: boolean = false;
 
   @ContentChildren(MatLine) _lines: QueryList<MatLine>;
@@ -130,7 +129,9 @@ export class MatListItem extends _MatListItemMixinBase implements AfterContentIn
   }
 
   ngAfterContentInit() {
-    this._lineSetter = new MatLineSetter(this._lines, this._element);
+    // TODO: consider turning the setter into a function, it doesn't do anything as a class.
+    // tslint:disable-next-line:no-unused-expression
+    new MatLineSetter(this._lines, this._element);
   }
 
   /** Whether this list item should show a ripple effect when clicked. */