1 files changed, 30 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/compositing/2d.composite.globalAlpha.image.html b/testing/web-platform/tests/html/canvas/offscreen/compositing/2d.composite.globalAlpha.image.html
new file mode 100644
index 0000000000..4590a2ea1f
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/compositing/2d.composite.globalAlpha.image.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.composite.globalAlpha.image</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.composite.globalAlpha.image</h1>
+<p class="desc"></p>
+
+
+<script>
+promise_test(async t => {
+
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  ctx.fillStyle = '#0f0';
+  ctx.fillRect(0, 0, 100, 50);
+  // Avoiding any potential alpha = 0 optimisations.
+  ctx.globalAlpha = 0.01;
+  const response = await fetch('/images/red.png');
+  const blob = await response.blob();
+  const bitmap = await createImageBitmap(blob);
+
+  ctx.drawImage(bitmap, 0, 0);
+  _assertPixelApprox(canvas, 50,25, 2,253,0,255, 2);
+
+}, "");
+</script>