Test for invalid input of webkitLineDash and webkitLineDashOffset On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS trySettingLineDash([1, 2, 3]) is [1, 2, 3] FAIL trySettingLineDash([1, -1]) should be 1.5,2.5. Was 1,-1. FAIL trySettingLineDash([1, Infinity]) should be 1.5,2.5. Was 1,Infinity. FAIL trySettingLineDash([1, -Infinity]) should be 1.5,2.5. Was 1,-Infinity. FAIL trySettingLineDash([1, NaN]) should be 1.5,2.5. Was 1,NaN. FAIL trySettingLineDash([1, 'string']) should be 1.5,2.5. Was 1,string. PASS trySettingLineDashOffset(0.5) is 0.5 PASS trySettingLineDashOffset(-0.5) is -0.5 FAIL trySettingLineDashOffset(Infinity) should be 1.5. Was Infinity. FAIL trySettingLineDashOffset(-Infinity) should be 1.5. Was -Infinity. FAIL trySettingLineDashOffset(NaN) should be 1.5. Was NaN. FAIL trySettingLineDashOffset('string') should be 1.5 (of type number). Was string (of type string). PASS successfullyParsed is true TEST COMPLETE