fix(ambilight): [PKG-AMBILIGHT-PROXY-01] sample canvas output pixels after resizing

test/ambilight-proxy.test.js

@@ -0,0 +1,53 @@
+import assert from 'node:assert/strict'
+// eslint-disable-next-line test/no-import-node-test -- Node runtime contract runner.
+import test from 'node:test'
+import { ambilightCandidate, ambilightEnvironment } from './helpers/ambilight.js'
+
+const implementation = await ambilightCandidate()
+
+test('Ambilight canvas proxy sampling follows output pixels and subsequent output resize', async () => {
+  const env = await ambilightEnvironment(implementation)
+  env.video.nodeName = 'CANVAS'
+  env.video.width = 600
+  env.video.height = 300
+  env.art.playing = true
+  env.time(100)
+  const result = env.factory()(env.art)
+  result.start()
+  assert.equal(env.draws.length, 9)
+  assert.deepEqual(env.draws[0].slice(1), [0, 0, 200, 100, 0, 0, 1, 1])
+  assert.deepEqual(env.draws[8].slice(1), [400, 200, 200, 100, 0, 0, 1, 1])
+  env.video.width = 300
+  env.video.height = 600
+  env.frame(200)
+  assert.deepEqual(env.draws[17].slice(1), [200, 400, 100, 200, 0, 0, 1, 1])
+  env.art.destroy()
+})
+
+test('Ambilight native video uses intrinsic pixels regardless of its display width and height', async () => {
+  const env = await ambilightEnvironment(implementation)
+  env.video.nodeName = 'VIDEO'
+  env.video.width = 600
+  env.video.height = 300
+  env.art.playing = true
+  env.time(100)
+  env.factory()(env.art).start()
+  assert.deepEqual(env.draws[8].slice(1), [200, 100, 100, 50, 0, 0, 1, 1])
+  env.art.destroy()
+})
+
+test('Ambilight zero-sized canvas output skips sampling despite nonzero proxy media dimensions and recovers on resize', async () => {
+  const env = await ambilightEnvironment(implementation)
+  env.video.nodeName = 'CANVAS'
+  env.video.width = 0
+  env.video.height = 300
+  env.art.playing = true
+  env.time(100)
+  env.factory()(env.art).start()
+  assert.equal(env.draws.length, 0)
+  env.video.width = 600
+  env.frame(200)
+  assert.equal(env.draws.length, 9)
+  env.art.destroy()
+  assert.equal(env.frames.size, 0)
+})