fix(auto-thumbnail): [PKG-AUTO-THUMB-12] release stalled metadata loads

test/auto-thumbnail-metadata.test.js

@@ -0,0 +1,102 @@
+import assert from 'node:assert/strict'
+// eslint-disable-next-line test/no-import-node-test -- Verify metadata wait ownership and cancellation.
+import test from 'node:test'
+import { autoThumbnailCandidate, autoThumbnailEnvironment } from './helpers/auto-thumbnail.js'
+
+const implementation = await autoThumbnailCandidate()
+async function setup() {
+  const env = autoThumbnailEnvironment(implementation)
+  const result = await env.factory({ width: 80, number: 1 })(env.art)
+  assert.equal(result.name, 'artplayerPluginAutoThumbnail')
+  env.art.emit('video:loadedmetadata')
+  return env
+}
+
+function released(env, video = env.videos[0]) {
+  assert.equal(env.attached.has(video), false)
+  assert.equal(video.src, undefined)
+  assert.equal(video.onloadedmetadata, null)
+  assert.equal(video.onerror, null)
+}
+
+test('Auto-thumbnail metadata timeout releases a stalled decoder and ignores late metadata', async () => {
+  const env = await setup()
+  const metadata = env.videos[0].onloadedmetadata
+  const deadline = [...env.timers.values()][0]
+  assert(deadline, 'Metadata loading must have an owned deadline')
+  assert.equal(deadline.delay, 30000)
+  deadline.callback()
+  released(env)
+  assert.equal(env.timers.size, 0)
+  assert.equal(env.warnings.length, 1)
+  assert.match(env.warnings[0][1].message, /metadata timed out/)
+  metadata()
+  deadline.callback()
+  assert.equal(env.canvases.length, 0)
+  assert.equal(env.updates.length, 0)
+  assert.equal(env.warnings.length, 1)
+  env.art.emit('destroy')
+})
+
+for (const scenario of ['destroy', 'restart', 'error', 'metadata']) {
+  test(`Auto-thumbnail metadata deadline becomes inert after ${scenario}`, async () => {
+    const env = await setup()
+    const deadline = [...env.timers.values()][0]
+    assert(deadline, 'Metadata loading must have an owned deadline')
+    if (scenario === 'metadata') {
+      env.metadata()
+      const frameDeadline = [...env.timers.values()][0]
+      assert.notEqual(frameDeadline, deadline)
+      deadline.callback()
+      assert.equal(env.timers.size, 1, 'A queued metadata timeout cannot cancel the new frame wait')
+      env.seeked()
+      env.finish()
+      assert.equal(env.updates.length, 1)
+    }
+    else if (scenario === 'error') {
+      env.videos[0].error = new Error('Media failed')
+      env.videos[0].onerror()
+    }
+    else {
+      env.art.emit(scenario)
+    }
+    deadline.callback()
+    released(env)
+    assert.equal(env.timers.size, 0)
+    assert.equal(env.warnings.length, scenario === 'error' ? 1 : 0)
+    env.art.emit('destroy')
+  })
+}
+
+test('Auto-thumbnail stalled replacement retains the previous usable sheet', async () => {
+  const env = await setup()
+  env.metadata()
+  env.seeked()
+  env.finish()
+  const sheet = env.art.thumbnails
+  env.art.emit('restart')
+  env.art.emit('video:loadedmetadata')
+  const deadline = [...env.timers.values()][0]
+  assert(deadline, 'Replacement metadata loading must have a deadline')
+  deadline.callback()
+  released(env, env.videos[1])
+  assert.equal(env.art.thumbnails, sheet)
+  assert.equal(env.urls.has(sheet.url), true)
+  assert.equal(env.updates.length, 1)
+  env.art.emit('destroy')
+  assert.equal(env.urls.size, 0)
+})
+
+test('Auto-thumbnail metadata timer registration cannot start loading after destruction', async () => {
+  const env = autoThumbnailEnvironment(implementation)
+  await env.factory({ width: 80, number: 1 })(env.art)
+  const schedule = env.box.setTimeout
+  env.box.setTimeout = (...args) => {
+    env.art.emit('destroy')
+    return schedule(...args)
+  }
+  env.art.emit('video:loadedmetadata')
+  released(env)
+  assert.equal(env.timers.size, 0)
+  assert.equal(env.canvases.length, 0)
+})