fix(thumbnail): [PKG-TOOL-THUMB-07] preserve falsy cleanup exceptions

test/thumbnail-cleanup-errors.test.js

@@ -0,0 +1,85 @@
+import assert from 'node:assert/strict'
+// eslint-disable-next-line test/no-import-node-test -- Compare cleanup exception identity with frozen releases.
+import test from 'node:test'
+import { thumbnailCandidate, thumbnailEnvironment, thumbnailHistorical } from './helpers/thumbnail.js'
+
+const candidate = await thumbnailCandidate()
+const failures = [undefined, null, false, 0, -0, '', Number.NaN]
+function attempt(callback) {
+  try {
+    callback()
+    return { threw: false }
+  }
+  catch (error) {
+    return { threw: true, error }
+  }
+}
+function create(implementation) {
+  const env = thumbnailEnvironment(implementation)
+  const input = new env.Element('input')
+  const tool = new env.Factory({ fileInput: input })
+  return { ...env, input, tool }
+}
+
+test('Thumbnail historical destroy listeners synchronously propagate falsy thrown values', () => {
+  for (const implementation of thumbnailHistorical()) {
+    for (const failure of failures) {
+      const { tool } = create(implementation)
+      tool.on('destroy', () => {
+        throw failure
+      })
+      const result = attempt(() => tool.destroy())
+      assert.equal(result.threw, true, implementation.name)
+      assert(Object.is(result.error, failure), implementation.name)
+    }
+  }
+})
+
+test('Thumbnail destroy preserves falsy listener exceptions after releasing native resources', () => {
+  for (const failure of failures) {
+    const { tool, input } = create(candidate)
+    let first = 0
+    let second = 0
+    tool.on('destroy', () => {
+      first++
+      throw failure
+    }).on('destroy', () => second++)
+    const result = attempt(() => tool.destroy())
+    assert.equal(result.threw, true)
+    assert(Object.is(result.error, failure))
+    assert.equal(tool.video.parentNode, null)
+    assert.equal(input.handlers.get('change')?.size || 0, 0)
+    assert.equal(first, 1)
+    assert.equal(second, 0, 'Normal emitter exception propagation still stops this dispatch')
+    assert.doesNotThrow(() => tool.destroy())
+    assert.equal(first, 1, 'Failed destroy is still terminal')
+  }
+})
+
+test('Thumbnail cleanup retains the first falsy failure and still attempts later cleanup and destroy notification', () => {
+  for (const failure of failures) {
+    const { tool, input, operations } = create(candidate)
+    tool.loadVideo({ name: 'first.mp4', type: 'video/mp4' })
+    const calls = []
+    tool.video.pause = () => {
+      calls.push('pause')
+      throw failure
+    }
+    tool.video.removeAttribute = name => calls.push(`remove:${name}`)
+    tool.video.load = () => {
+      calls.push('load')
+      throw new Error('later decoder reset error')
+    }
+    tool.on('destroy', () => {
+      calls.push('destroy')
+      throw new Error('later listener error')
+    })
+    const result = attempt(() => tool.destroy())
+    assert.equal(result.threw, true)
+    assert(Object.is(result.error, failure), 'Later errors cannot replace the first thrown value')
+    assert.deepEqual(calls, ['pause', 'remove:src', 'load', 'destroy'])
+    assert.equal(tool.video.parentNode, null)
+    assert.equal(input.handlers.get('change')?.size || 0, 0)
+    assert.deepEqual(operations.filter(item => item.name === 'revokeURL').map(item => item.url), [tool.videoUrl])
+  }
+})