Wingsuit base-jumping video well worth watching

The above video was sent to my attention recently. Although it's been on YouTube since June, it's still awesome to watch.

Makes me wish I knew more both about the wingsuit and the man wearing it. He certainly displays some daring moves as he navigates cliffs and mountaintops before opening his parachute.

One thing I keep wondering is: How does one test such a suit to make sure it works as intended before jumping?