
PASS registerProperty requires a Dictionary type 
PASS registerProperty requires a name matching <custom-property-name> 
FAIL registerProperty only allows omitting initialValue if syntax is '*' assert_throws: function "() => CSS.registerProperty({name: '--syntax-test-3', syntax: 'length', inherits: false})" did not throw
FAIL registerProperty fails for an already registered property assert_throws: function "() => CSS.registerProperty({name: '--re-register', syntax: '<percentage>', initialValue: '0%', inherits: false})" threw object "SyntaxError: The given initial value does not parse for the given syntax." ("SyntaxError") expected object "[object Object]" ("InvalidModificationError")
PASS registerProperty requires inherits 
FAIL Registering a property should not cause a transition The given initial value does not parse for the given syntax.