Safari Tech Preview is failing due to its non-standard region implementation. It can pass if accounting for it.
Firefox is failing due to throwing an error when cue.region is set to a value other than a VTTRegion or null. An error is not supposed to be thrown.
Browsers implemented this field as an int but it is specced as a long.
This refers to HTML character entities, a standard set of HTML character entities is available in all browsers and an older version of the spec only included a couple of allowed characters. Currently, all HTML character entities are allowed. There is an oustanding bug against Safari for implementing this and there is a POC for vtt.js.
This is failing in Firefox because it ends up stopping parsing the regions at the first edge case so only the first region is available. Safari fails due to its non-standard region implementation. It can pass if accounting for it.
This is failing in Safari due to its non-standard region implementation. It can pass if accounting for it.
Both Safari and Firefox are failing here due to implementation dependent versions of "interpret value as integer". Safari is clamping the value to the max integer value while Firefox returns a 0. Also, Firefox's very strict parser and Safari's non-standard region implementation is making this test fail.
Chrome and Safari fail because it is parsing .5 and 5., which are explicitly disallowed, as 0.5 and 5.0. Chrome and Safari do not support line align.
Safari defaults to the value -1 rather than auto. Safari also sets a really small value to zero rather than Number.MIN_VALUE.
Chrome and Safari don't support position align, excluding that piece from the test makes it pass.
This is failing because text-wrap: balance; isn't available in any browser.
There's a bug for vertical handling where lr and rl cues are swapped. There's a fix in progress on Safari's side.
These are all implementation issues. The text-combine-upright CSS property hasn't been whitelisted by them.