1 files changed, 41 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/the-canvas-state/2d.state.saverestore.globalAlpha.html b/testing/web-platform/tests/html/canvas/offscreen/the-canvas-state/2d.state.saverestore.globalAlpha.html
new file mode 100644
index 0000000000..15b59725ab
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/the-canvas-state/2d.state.saverestore.globalAlpha.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.state.saverestore.globalAlpha</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.state.saverestore.globalAlpha</h1>
+<p class="desc">save()/restore() works for globalAlpha</p>
+
+
+<script>
+var t = async_test("save()/restore() works for globalAlpha");
+var t_pass = t.done.bind(t);
+var t_fail = t.step_func(function(reason) {
+    throw reason;
+});
+t.step(function() {
+
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  // Test that restore() undoes any modifications
+  var old = ctx.globalAlpha;
+  ctx.save();
+  ctx.globalAlpha = 0.5;
+  ctx.restore();
+  _assertSame(ctx.globalAlpha, old, "ctx.globalAlpha", "old");
+
+  // Also test that save() doesn't modify the values
+  ctx.globalAlpha = 0.5;
+  old = ctx.globalAlpha;
+      // we're not interested in failures caused by get(set(x)) != x (e.g.
+      // from rounding), so compare against 'old' instead of against 0.5
+  ctx.save();
+  _assertSame(ctx.globalAlpha, old, "ctx.globalAlpha", "old");
+  ctx.restore();
+  t.done();
+
+});
+</script>