chromium/third_party/blink/web_tests/fast/canvas/canvas-toBlob-oversized.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<script>

async_test(t => {
  var png_max_dimension = 65535;
  var canvas = document.createElement("canvas");
  canvas.width = 10;
  canvas.height = png_max_dimension + 1;

  canvas.toBlob(function(blob) {
    t.done();
  }, "image/png", 1.0);
}, "Verify that toBlob does not crash when encoding oversized canvas to Png.");

async_test(t => {
  // Based on third_party/libjpeg/jmorecfg.h:JPEG_MAX_DIMENSION
  var jpeg_max_dimension = 65500;
  var canvas = document.createElement("canvas");
  canvas.width = 10;
  canvas.height = jpeg_max_dimension + 1;

  canvas.toBlob(function(blob) {
    t.done();
  }, "image/jpeg", 1.0);
}, "Verify that toBlob does not crash when encoding oversized canvas to Jpeg.");

async_test(t => {
  // Based on third_party/libwebp/src/webp/encode.h:WEBP_MAX_DIMENSION
  var webp_max_dimension = 16383;
  var canvas = document.createElement("canvas");
  canvas.width = 10;
  canvas.height = webp_max_dimension + 1;

  canvas.toBlob(function(blob) {
    t.done();
  }, "image/webp", 1.0);
}, "Verify that toBlob does not crash when encoding oversized canvas to Webp.");

</script>