#[gpu_test]
static MAP_WITHOUT_SUBMIT: GpuTestConfiguration = GpuTestConfiguration::new().run_async(|ctx| async move {
    let buffer = ctx.device.create_buffer(&wgpu::BufferDescriptor {
        label: None,
        size: 12,
        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
        mapped_at_creation: true,
    });

    {
        let mut mapped = buffer.slice(0..12).get_mapped_range_mut();
        assert!(mapped.len() == 12);
        for (i, elt) in mapped.iter_mut().enumerate() {
            *elt = (i %255) as u8;
        }    
    }

    buffer.unmap();

    // Uncommenting this makes the test pass
    //ctx.queue.submit([]);

    buffer.slice(0..12).map_async(wgpu::MapMode::Read, Result::unwrap);

    ctx.async_poll(wgpu::Maintain::wait())
        .await
        .panic_on_timeout();

    {
        let mapped = buffer.slice(0..12).get_mapped_range();
        assert!(mapped.len() == 12);
        for (i, elt) in mapped.iter().enumerate() {
            assert_eq!(*elt, (i %255) as u8); // Boom.
        }
    }

    buffer.unmap();
});