Quick question - when Chrome introduced "tabGroups", were there some compatibility issues with existing extensions?

[Juraj M.]

For example when using `tabs.move` API?

[Tony Confrey]

I was an early adopter of using tab groups in my extension. It's a pretty thin API, so there's not much to have in conflict. My extension has the notion of sets of tabs being part of a 'topic', so it was nice to be able to show the grouping when the tabs were open.

Where I've had problems is the recent addition of saving tab groups and displaying them on the bookmarks bar. Those capabilities are not exposed via the api. An extension has no way of knowing about any tab groups when they are not open in tabs.

So for example the user can be seeing a tab group named 'Foo' on their bookmark bar but in my extension when they add a tab to the 'Foo' topic in their topic tree it creates a new tab group called 'Foo'. Now there are two tab groups with the same name. 

[Mythical 5th]

> An extension has no way of knowing about any tab groups when they are not open in tabs.

The sessions API has a similar problem - no way to know about tab groups when they have been closed! If you close a tab group then it appears as a named group in the Recent Tabs section of the History menu, and can be restored as a group. However, an extension using the sessions API to display a list of tabs the user can restore is unable to restore them as a group, or indicate that they are part of a group.

[Tony Confrey]

FWIW, I opened a ticket on this: https://github.com/w3c/webextensions/issues/715