1 files changed, 92 insertions, 0 deletions
diff --git a/dom/webgpu/tests/cts/checkout/src/webgpu/api/operation/device/lost.spec.ts b/dom/webgpu/tests/cts/checkout/src/webgpu/api/operation/device/lost.spec.ts
new file mode 100644
index 0000000000..88d08b77f5
--- /dev/null
+++ b/dom/webgpu/tests/cts/checkout/src/webgpu/api/operation/device/lost.spec.ts
@@ -0,0 +1,92 @@
+export const description = `
+Tests for GPUDevice.lost.
+`;
+
+import { Fixture } from '../../../../common/framework/fixture.js';
+import { makeTestGroup } from '../../../../common/framework/test_group.js';
+import { attemptGarbageCollection } from '../../../../common/util/collect_garbage.js';
+import { getGPU } from '../../../../common/util/navigator_gpu.js';
+import {
+  assert,
+  assertNotSettledWithinTime,
+  raceWithRejectOnTimeout,
+} from '../../../../common/util/util.js';
+
+class DeviceLostTests extends Fixture {
+  // Default timeout for waiting for device lost is 2 seconds.
+  readonly kDeviceLostTimeoutMS = 2000;
+
+  getDeviceLostWithTimeout(lost: Promise<GPUDeviceLostInfo>): Promise<GPUDeviceLostInfo> {
+    return raceWithRejectOnTimeout(lost, this.kDeviceLostTimeoutMS, 'device was not lost');
+  }
+
+  expectDeviceDestroyed(device: GPUDevice): void {
+    this.eventualAsyncExpectation(async niceStack => {
+      try {
+        const lost = await this.getDeviceLostWithTimeout(device.lost);
+        this.expect(lost.reason === 'destroyed', 'device was lost from destroy');
+      } catch (ex) {
+        niceStack.message = 'device was not lost';
+        this.rec.expectationFailed(niceStack);
+      }
+    });
+  }
+}
+
+export const g = makeTestGroup(DeviceLostTests);
+
+g.test('not_lost_on_gc')
+  .desc(
+    `'lost' is never resolved by GPUDevice being garbage collected (with attemptGarbageCollection).`
+  )
+  .fn(async t => {
+    // Wraps a lost promise object creation in a function scope so that the device has the best
+    // chance of being gone and ready for GC before trying to resolve the lost promise.
+    const { lost } = await (async () => {
+      const adapter = await getGPU().requestAdapter();
+      assert(adapter !== null);
+      const lost = (await adapter.requestDevice()).lost;
+      return { lost };
+    })();
+    await assertNotSettledWithinTime(lost, t.kDeviceLostTimeoutMS, 'device was unexpectedly lost');
+
+    await attemptGarbageCollection();
+  });
+
+g.test('lost_on_destroy')
+  .desc(`'lost' is resolved, with reason='destroyed', on GPUDevice.destroy().`)
+  .fn(async t => {
+    const adapter = await getGPU().requestAdapter();
+    assert(adapter !== null);
+    const device: GPUDevice = await adapter.requestDevice();
+    t.expectDeviceDestroyed(device);
+    device.destroy();
+  });
+
+g.test('same_object')
+  .desc(`'lost' provides the same Promise and GPUDeviceLostInfo objects each time it's accessed.`)
+  .fn(async t => {
+    const adapter = await getGPU().requestAdapter();
+    assert(adapter !== null);
+    const device: GPUDevice = await adapter.requestDevice();
+
+    // The promises should be the same promise object.
+    const lostPromise1 = device.lost;
+    const lostPromise2 = device.lost;
+    t.expect(lostPromise1 === lostPromise2);
+
+    // Promise object should still be the same after destroy.
+    device.destroy();
+    const lostPromise3 = device.lost;
+    t.expect(lostPromise1 === lostPromise3);
+
+    // The results should also be the same result object.
+    const lost1 = await t.getDeviceLostWithTimeout(lostPromise1);
+    const lost2 = await t.getDeviceLostWithTimeout(lostPromise2);
+    const lost3 = await t.getDeviceLostWithTimeout(lostPromise3);
+    // Promise object should still be the same after we've been notified about device loss.
+    const lostPromise4 = device.lost;
+    t.expect(lostPromise1 === lostPromise4);
+    const lost4 = await t.getDeviceLostWithTimeout(lostPromise4);
+    t.expect(lost1 === lost2 && lost2 === lost3 && lost3 === lost4);
+  });