Test the computed style of the spring() function on the transition-timing-function property. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". Valid spring tests Basic : spring(1 100 10 0) PASS springStyle.cssText is 'spring(1 100 10 0)' Negative Velocity : spring(1 100 10 -10) PASS springStyle.cssText is 'spring(1 100 10 -10)' Positive Velocity : spring(1 100 10 10) PASS springStyle.cssText is 'spring(1 100 10 10)' Zero Damping : spring(1 100 0 10) PASS springStyle.cssText is 'spring(1 100 0 10)' Minimum Values : spring(1 1 0 -999999) PASS springStyle.cssText is 'spring(1 1 0 -999999)' Floating Point Values : spring(1.5 2.3 3.7 -1.8) PASS springStyle.cssText is 'spring(1.5 2.3 3.7 -1.8)' Invalid spring tests No parameters : spring() PASS springStyle.cssText is 'ease' Not enough parameters : spring(1 100 10) PASS springStyle.cssText is 'ease' Too many parameters : spring(1 100 10 0 0) PASS springStyle.cssText is 'ease' Non-numeric parameters : spring(a b c d) PASS springStyle.cssText is 'ease' Illegal Mass (< 0) : spring(-1 100 10 0) PASS springStyle.cssText is 'ease' Illegal Mass (== 0) : spring(0 100 10 0) PASS springStyle.cssText is 'ease' Illegal Stiffness (< 0) : spring(1 -1 10 0) PASS springStyle.cssText is 'ease' Illegal Stiffness (== 0) : spring(1 0 10 0) PASS springStyle.cssText is 'ease' Illegal Damping (< 0) : spring(1 100 -1 0) PASS springStyle.cssText is 'ease' PASS successfullyParsed is true TEST COMPLETE