1 files changed, 23 insertions, 0 deletions
diff --git a/dom/webgpu/tests/cts/checkout/src/webgpu/web_platform/reftests/create-pattern-data-url.ts b/dom/webgpu/tests/cts/checkout/src/webgpu/web_platform/reftests/create-pattern-data-url.ts
new file mode 100644
index 0000000000..aa96bbd85b
--- /dev/null
+++ b/dom/webgpu/tests/cts/checkout/src/webgpu/web_platform/reftests/create-pattern-data-url.ts
@@ -0,0 +1,23 @@
+// creates a 4x4 pattern
+export default function createPatternDataURL() {
+  const patternSize = 4;
+  const ctx = document.createElement('canvas').getContext('2d')!;
+  ctx.canvas.width = patternSize;
+  ctx.canvas.height = patternSize;
+
+  const b = [0, 0, 0, 255];
+  const t = [0, 0, 0, 0];
+  const r = [255, 0, 0, 255];
+  const g = [0, 255, 0, 255];
+
+  const imageData = new ImageData(patternSize, patternSize);
+  // prettier-ignore
+  imageData.data.set([
+    b, t, t, r,
+    t, b, g, t,
+    t, r, b, t,
+    g, t, t, b,
+  ].flat());
+  ctx.putImageData(imageData, 0, 0);
+  return { patternSize, imageData, dataURL: ctx.canvas.toDataURL() };
+}