fix: [fixes #175] Do not resume complete Tweenables in Scene (#176)

* fix: [#175] don't resume completed tweenables in scene
* test: validate that stopped tweenables are not resumed by scene.resume

src/scene.js

@@ -43,6 +43,16 @@ export class Scene {
     return [...this.#tweenables]
   }
 
+  /**
+   * A list of {@link Tweenable}s in the scene that have not yet ended (playing
+   * or not).
+   * @member Scene#playingTweenables
+   * @type {Array.<Tweenable>}
+   */
+  get playingTweenables() {
+    return this.#tweenables.filter(tweenable => !tweenable.hasEnded())
+  }
+
   /**
    * The {@link external:Promise}s for all {@link Tweenable}s in this
    * {@link Scene} that have been configured with {@link
@@ -146,7 +156,7 @@ export class Scene {
    * @return {Scene}
    */
   resume() {
-    this.#tweenables.forEach(tweenable => tweenable.resume())
+    this.playingTweenables.forEach(tweenable => tweenable.resume())
 
     return this
   }

src/scene.test.js

@@ -109,13 +109,32 @@ describe('resume', () => {
     scene = new Scene(new Tweenable(), new Tweenable())
   })
 
-  test('resumes all Tweenables', () => {
+  test('resumes Tweenables', () => {
     scene.play()
     scene.pause()
     scene.resume()
 
     expect(scene.isPlaying()).toBeTruthy()
   })
+
+  test('does not resume Tweenables that have ended', () => {
+    const tweenable1 = new Tweenable()
+    const tweenable2 = new Tweenable()
+
+    scene = new Scene(tweenable1, tweenable2)
+
+    jest.spyOn(tweenable1, 'hasEnded').mockReturnValue(false)
+    jest.spyOn(tweenable1, 'resume')
+    jest.spyOn(tweenable2, 'hasEnded').mockReturnValue(true)
+    jest.spyOn(tweenable2, 'resume')
+
+    scene.play()
+    scene.pause()
+    scene.resume()
+
+    expect(tweenable1.resume).toHaveBeenCalled()
+    expect(tweenable2.resume).not.toHaveBeenCalled()
+  })
 })
 
 describe('stop', () => {