| PASS | add on DOMTokenList must enqueue an attributeChanged reaction when adding an attribute | |
| PASS | add on DOMTokenList must not enqueue an attributeChanged reaction when adding an unobserved attribute | |
| PASS | add on DOMTokenList must enqueue an attributeChanged reaction when adding a value to an existing attribute | |
| PASS | add on DOMTokenList must not enqueue an attributeChanged reaction when adding a value to an unobserved attribute | |
| PASS | add on DOMTokenList must enqueue exactly one attributeChanged reaction when adding multiple values to an attribute | |
| PASS | remove on DOMTokenList must enqueue an attributeChanged reaction when removing a value from an attribute | |
| PASS | remove on DOMTokenList must enqueue exactly one attributeChanged reaction when removing multiple values to an attribute | |
| PASS | remove on DOMTokenList must enqueue an attributeChanged reaction even when removing a non-existent value from an attribute | |
| PASS | remove on DOMTokenList must not enqueue an attributeChanged reaction when removing a value from an unobserved attribute | |
| PASS | toggle on DOMTokenList must enqueue an attributeChanged reaction when adding a value to an attribute | |
| PASS | toggle on DOMTokenList must enqueue an attributeChanged reaction when removing a value from an attribute | |
| PASS | replace on DOMTokenList must enqueue an attributeChanged reaction when replacing a value in an attribute | |
| PASS | replace on DOMTokenList must not enqueue an attributeChanged reaction when the token to replace does not exist in the attribute | |
| PASS | replace on DOMTokenList must not enqueue an attributeChanged reaction when replacing a value in an unobserved attribute | |
| PASS | the stringifier of DOMTokenList must enqueue an attributeChanged reaction when adding an observed attribute | |
| PASS | the stringifier of DOMTokenList must not enqueue an attributeChanged reaction when adding an unobserved attribute | |
| PASS | the stringifier of DOMTokenList must enqueue an attributeChanged reaction when mutating the value of an observed attribute | |
| PASS | the stringifier of DOMTokenList must not enqueue an attributeChanged reaction when mutating the value of an unobserved attribute | |
| PASS | the stringifier of DOMTokenList must enqueue an attributeChanged reaction when the setter is called with the original value of the attribute | |