Introduce Abort Initialisation After TearDown (#400)

* add abort utils

* add abort signal to bsp and playback strategy

* add bsp abort tests

* use the existing getError

* add playercomponent abort signal tests

* remove abortStage

* move abortstage constants into models and update error messaging

Author: terminal-overflow

src/bigscreenplayer.js

@@ -22,6 +22,8 @@ import ReadyHelper from "./readyhelper"
 import Subtitles from "./subtitles/subtitles"
 import { ManifestType } from "./models/manifesttypes"
 import { Timeline } from "./models/timeline"
+import { AbortSignal } from "./utils/abortutils"
+import { AbortStages } from "./models/abortstages"
 
 /**
  * @import {
@@ -53,6 +55,8 @@ function BigscreenPlayer() {
 
   const END_OF_STREAM_TOLERANCE = 10
 
+  const abortSignal = new AbortSignal()
+
   function mediaStateUpdateCallback(evt) {
     if (evt.timeUpdate) {
       callCallbacks(_callbacks.timeUpdate, {
@@ -106,6 +110,8 @@ function BigscreenPlayer() {
   }
 
   function bigscreenPlayerDataLoaded({ media, enableSubtitles, enableAudioDescribed }) {
+    abortSignal.throwIfAborted(AbortStages.DATA_LOADED)
+
     const initialPresentationTime =
       initialPlaybackTime == null ? undefined : convertPlaybackTimeToPresentationTimeInSeconds(initialPlaybackTime)
 
@@ -120,7 +126,8 @@ function BigscreenPlayer() {
       mediaSources,
       mediaStateUpdateCallback,
       _callbacks.playerError,
-      callAudioDescribedCallbacks
+      callAudioDescribedCallbacks,
+      abortSignal
     )
 
     readyHelper = ReadyHelper(
@@ -311,6 +318,8 @@ function BigscreenPlayer() {
      * @name tearDown
      */
     tearDown() {
+      abortSignal.abort()
+
       if (subtitles) {
         subtitles.tearDown()
         subtitles = undefined

src/bigscreenplayer.test.js

@@ -12,6 +12,7 @@ import MediaState from "./models/mediastate"
 import PauseTriggers from "./models/pausetriggers"
 import { Timeline } from "./models/timeline"
 import getError, { NoErrorThrownError } from "./testutils/geterror"
+import { AbortStages } from "./models/abortstages"
 
 let bigscreenPlayer
 let bigscreenPlayerData
@@ -194,7 +195,8 @@ describe("Bigscreen Player", () => {
         expect.any(Object),
         expect.any(Function),
         expect.any(Function),
-        expect.any(Function)
+        expect.any(Function),
+        expect.objectContaining({ aborted: false })
       )
     })
 
@@ -234,7 +236,8 @@ describe("Bigscreen Player", () => {
           expect.any(Object),
           expect.any(Function),
           expect.any(Function),
-          expect.any(Function)
+          expect.any(Function),
+          expect.objectContaining({ aborted: false })
         )
       })
 
@@ -253,7 +256,8 @@ describe("Bigscreen Player", () => {
           expect.any(Object),
           expect.any(Function),
           expect.any(Function),
-          expect.any(Function)
+          expect.any(Function),
+          expect.objectContaining({ aborted: false })
         )
       })
 
@@ -273,7 +277,8 @@ describe("Bigscreen Player", () => {
           expect.any(Object),
           expect.any(Function),
           expect.any(Function),
-          expect.any(Function)
+          expect.any(Function),
+          expect.objectContaining({ aborted: false })
         )
       })
 
@@ -297,7 +302,8 @@ describe("Bigscreen Player", () => {
           expect.any(Object),
           expect.any(Function),
           expect.any(Function),
-          expect.any(Function)
+          expect.any(Function),
+          expect.objectContaining({ aborted: false })
         )
       })
 
@@ -321,7 +327,8 @@ describe("Bigscreen Player", () => {
           expect.any(Object),
           expect.any(Function),
           expect.any(Function),
-          expect.any(Function)
+          expect.any(Function),
+          expect.objectContaining({ aborted: false })
         )
       })
 
@@ -346,10 +353,27 @@ describe("Bigscreen Player", () => {
           expect.any(Object),
           expect.any(Function),
           expect.any(Function),
-          expect.any(Function)
+          expect.any(Function),
+          expect.objectContaining({ aborted: false })
         )
       })
     })
+
+    describe("aborting during initialization", () => {
+      it("aborts if bigscreen player has been torn down", async () => {
+        bigscreenPlayer.tearDown()
+        const error = await getError(() => asyncInitialiseBigscreenPlayer(createPlaybackElement(), bigscreenPlayerData))
+
+        expect(error).toHaveProperty("name", "AbortError")
+        expect(error).toHaveProperty("message", `bigscreen-player aborted at ${AbortStages.DATA_LOADED}`)
+      })
+
+      it("does not abort if bigscreen player has not been torn down", async () => {
+        const error = await getError(() => asyncInitialiseBigscreenPlayer(createPlaybackElement(), bigscreenPlayerData))
+
+        expect(error).toBeInstanceOf(NoErrorThrownError)
+      })
+    })
   })
 
   describe("tearDown", () => {

src/models/abortstages.ts

@@ -0,0 +1,7 @@
+export const AbortStages = {
+  DATA_LOADED: "bigscreen-player-data-loaded",
+  PLAYER_COMPONENT: "bigscreen-player-player-component",
+  STRATEGY: "bigscreen-player-strategy",
+} as const
+
+export type AbortStages = (typeof AbortStages)[keyof typeof AbortStages]

src/models/mediakinds.ts

@@ -1,5 +1,5 @@
-const AUDIO = "audio" as const
-const VIDEO = "video" as const
+const AUDIO = "audio"
+const VIDEO = "video"
 
 export const MediaKinds = { AUDIO, VIDEO } as const
 

src/playercomponent.js

@@ -9,6 +9,7 @@ import PluginData from "./plugindata"
 import PluginEnums from "./pluginenums"
 import Plugins from "./plugins"
 import DebugTool from "./debugger/debugtool"
+import { AbortStages } from "./models/abortstages"
 
 /**
  * @import { InitData } from './types.d.ts'
@@ -41,7 +42,8 @@ function PlayerComponent(
   mediaSources,
   stateUpdateCallback,
   errorCallback,
-  audioDescribedCallback
+  audioDescribedCallback,
+  abortSignal
 ) {
   let setSubtitlesState
   let _stateUpdateCallback = stateUpdateCallback
@@ -57,10 +59,13 @@ function PlayerComponent(
 
   StrategyPicker()
     .then((strategy) => {
+      abortSignal.throwIfAborted(AbortStages.PLAYER_COMPONENT)
+
       playbackStrategy = strategy(
         mediaSources,
         mediaKind,
         playbackElement,
+        abortSignal,
         bigscreenPlayerData.media.isUHD,
         bigscreenPlayerData.media.playerSettings,
         {