1 files changed, 80 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.getcontext.html b/testing/web-platform/tests/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.getcontext.html
new file mode 100644
index 0000000000..51c167ddca
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.getcontext.html
@@ -0,0 +1,80 @@
+<!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-getcontext">
+<script>
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(1, 1);
+    assert_throws_js(TypeError, function() { offscreenCanvas.getContext('3d'); });
+}, "Test that getContext with un-supported string throws a TypeError.");
+
+test(function() {
+    var offscreenCanvas1 = new OffscreenCanvas(1, 1);
+    var ctx1 = offscreenCanvas1.getContext('2d');
+    assert_true(ctx1 instanceof OffscreenCanvasRenderingContext2D);
+
+    var offscreenCanvas2 = new OffscreenCanvas(1, 1);
+    var ctx2 = offscreenCanvas2.getContext('webgl');
+    assert_true(ctx2 instanceof WebGLRenderingContext);
+
+    var offscreenCanvas3 = new OffscreenCanvas(1, 1);
+    var ctx3 = offscreenCanvas3.getContext('webgl2');
+    assert_true(ctx3 instanceof WebGL2RenderingContext);
+}, "Test that getContext with supported string returns correct results");
+
+test(function() {
+    var offscreenCanvas1 = new OffscreenCanvas(1, 1);
+    var ctx1 = offscreenCanvas1.getContext('2d');
+    var ctx2 = offscreenCanvas1.getContext('webgl');
+    assert_equals(ctx2, null);
+
+    var offscreenCanvas2 = new OffscreenCanvas(1, 1);
+    var ctx3 = offscreenCanvas2.getContext('webgl');
+    var ctx4 = offscreenCanvas2.getContext('2d');
+    assert_equals(ctx4, null);
+}, "Test that getContext twice with different context type returns null the second time");
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(1, 2);
+    var ctx = offscreenCanvas.getContext('2d');
+    var dstCanvas = ctx.canvas;
+    assert_equals(dstCanvas.width, 1);
+    assert_equals(dstCanvas.height, 2);
+}, "Test that 2dcontext.canvas should return the original OffscreenCanvas");
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(1, 2);
+    var ctx = offscreenCanvas.getContext('webgl');
+    var dstCanvas = ctx.canvas;
+    assert_equals(dstCanvas.width, 1);
+    assert_equals(dstCanvas.height, 2);
+}, "Test that webglcontext.canvas should return the original OffscreenCanvas");
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(10, 10);
+    var ctx = offscreenCanvas.getContext('2d', {alpha: false});
+    ctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
+    ctx.fillRect(0, 0, 10, 10);
+    _assertPixelApprox(offscreenCanvas, 5,5, 0,127,0,255, 2);
+}, "Test that OffscreenCanvasRenderingContext2D with alpha disabled makes the OffscreenCanvas opaque");
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(10, 10);
+    var ctx = offscreenCanvas.getContext('2d', {alpha: true});
+    ctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
+    ctx.fillRect(0, 0, 10, 10);
+    _assertPixelApprox(offscreenCanvas, 5,5, 0,255,0,127, 2);
+}, "Test that OffscreenCanvasRenderingContext2D with alpha enabled preserves the alpha");
+
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(10, 10);
+    var ctx = offscreenCanvas.getContext('2d');
+    ctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
+    ctx.fillRect(0, 0, 10, 10);
+    _assertPixelApprox(offscreenCanvas, 5,5, 0,255,0,127, 2);
+}, "Test that 'alpha' context creation attribute is true by default");
+
+</script>
+