fix: unsubscribe all observables when the component is destroyed

Closes #27

src/resizable.directive.ts

@@ -9,7 +9,8 @@ import {
   Input,
   EventEmitter,
   ContentChildren,
-  QueryList
+  QueryList,
+  OnDestroy
 } from '@angular/core';
 import {Subject} from 'rxjs/Subject';
 import {Observable} from 'rxjs/Observable';
@@ -226,7 +227,7 @@ export class ResizeHandle {
 @Directive({
   selector: '[mwlResizable]'
 })
-export class Resizable implements OnInit, AfterViewInit {
+export class Resizable implements OnInit, OnDestroy, AfterViewInit {
 
   /**
    * A function that will be called before each resize event. Return `true` to allow the resize event to propagate or `false` to cancel it
@@ -474,6 +475,15 @@ export class Resizable implements OnInit, AfterViewInit {
     });
   }
 
+  /**
+   * @private
+   */
+  ngOnDestroy(): void {
+    this.mousedown.complete();
+    this.mouseup.complete();
+    this.mousemove.complete();
+  }
+
   /**
    * @private
    */

test/resizable.spec.ts

@@ -972,4 +972,37 @@ describe('resizable directive', () => {
 
   });
 
+  it('should end the mouseup observable when the component is destroyed', () => {
+
+    const fixture: ComponentFixture<TestCmp> = createComponent();
+    fixture.detectChanges();
+    const onComplete: sinon.SinonSpy = sinon.spy();
+    fixture.componentInstance.resizable.mouseup.subscribe(() => '', () => '', onComplete);
+    fixture.destroy();
+    expect(onComplete).to.have.been.calledOnce;
+
+  });
+
+  it('should end the mousedown observable when the component is destroyed', () => {
+
+    const fixture: ComponentFixture<TestCmp> = createComponent();
+    fixture.detectChanges();
+    const onComplete: sinon.SinonSpy = sinon.spy();
+    fixture.componentInstance.resizable.mousedown.subscribe(() => '', () => '', onComplete);
+    fixture.destroy();
+    expect(onComplete).to.have.been.calledOnce;
+
+  });
+
+  it('should end the mousemove observable when the component is destroyed', () => {
+
+    const fixture: ComponentFixture<TestCmp> = createComponent();
+    fixture.detectChanges();
+    const onComplete: sinon.SinonSpy = sinon.spy();
+    fixture.componentInstance.resizable.mousemove.subscribe(() => '', () => '', onComplete);
+    fixture.destroy();
+    expect(onComplete).to.have.been.calledOnce;
+
+  });
+
 });