jpegxl/imagedecoder.https.html

<!DOCTYPE html>
<title>JPEG XL integration: ImageDecoder API</title>
<link rel="help" href="https://github.com/web-platform-tests/interop-jpegxl">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
promise_test(async () => {
  assert_true('ImageDecoder' in self, 'ImageDecoder should exist');
  const supported = await ImageDecoder.isTypeSupported('image/jxl');
  assert_true(supported, 'image/jxl should be supported');

  const response = await fetch('resources/3x3_srgb_lossless.jxl');
  const decoder = new ImageDecoder({data: response.body, type: 'image/jxl'});
  await decoder.tracks.ready;
  const result = await decoder.decode();

  assert_equals(result.image.displayWidth, 3);
  assert_equals(result.image.displayHeight, 3);

  result.image.close();
  decoder.close();
}, 'ImageDecoder decodes JPEG XL image stream.');
</script>