t_interpolation({
  property: 'box-shadow',
  from: 'unset',
  to: '20px 20px 20px 20px black',
}, [
  {at: -0.3, expect: 'rgba(0, 0, 0, 0) -6px -6px 0px -6px'},
  {at: 0, expect: 'rgba(0, 0, 0, 0) 0px 0px 0px 0px'},
  {at: 0.3, expect: 'rgba(0, 0, 0, 0.3) 6px 6px 6px 6px'},
  {at: 0.6, expect: 'rgba(0, 0, 0, 0.6) 12px 12px 12px 12px'},
  {at: 1, expect: 'rgb(0, 0, 0) 20px 20px 20px 20px'},
  {at: 1.5, expect: 'rgb(0, 0, 0) 30px 30px 30px 30px'},
]);

// Test basic functionality, and clipping blur at 0
test