1 files changed, 51 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.constructor.html b/testing/web-platform/tests/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.constructor.html
new file mode 100644
index 0000000000..a2ad1dcc7e
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.constructor.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="help" href="https://html.spec.whatwg.org/#dom-offscreencanvas">
+<script>
+
+test(function() {
+  assert_throws_js(
+    TypeError,
+    () => OffscreenCanvas(100, 50),
+    "Calling OffscreenCanvas constructor without 'new' must throw"
+  );
+}, "OffscreenCanvas constructor called as normal function");
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(100, 50);
+    assert_equals(offscreenCanvas.width, 100);
+    assert_equals(offscreenCanvas.height, 50);
+
+    offscreenCanvas.width = 50;
+    offscreenCanvas.height = 100;
+    assert_equals(offscreenCanvas.width, 50);
+    assert_equals(offscreenCanvas.height, 100);
+}, "Test that calling OffscreenCanvas's constructor generates correct width and height.");
+
+test(function() {
+    var offscreenCanvas1 = new OffscreenCanvas(1, 1);
+
+    offscreenCanvas1.width = null;
+    offscreenCanvas1.height = null;
+    assert_equals(offscreenCanvas1.width, 0);
+    assert_equals(offscreenCanvas1.height, 0);
+
+    assert_throws_js(TypeError, function() { new OffscreenCanvas(-1, -1); });
+
+    var offscreenCanvas2 = new OffscreenCanvas(null, null);
+    assert_equals(offscreenCanvas2.width, 0);
+    assert_equals(offscreenCanvas2.height, 0);
+
+    assert_throws_js(TypeError, function() { offscreenCanvas2.width = -1; });
+    assert_throws_js(TypeError, function() { offscreenCanvas2.height = -1; });
+
+    var obj = {Name: "John Doe", Age: 30};
+    assert_throws_js(TypeError, function() { offscreenCanvas2.width = obj; });
+    assert_throws_js(TypeError, function() { offscreenCanvas2.height = obj; });
+    assert_throws_js(TypeError, function() { new OffscreenCanvas(obj, obj); });
+}, "Test that OffscreenCanvas constructor handles invalid arguments correctly");
+
+</script>
+