Optimize moving tabs inside the same window

[Lej77]

I noticed that moving all tabs inside a window to a new panel could be quite slow so I took a look at the code in order to optimize it. I suspect that it was the left over TODO: Do not call this fn if: all tabs go one after another and srcIndex === dstIndex that was the cause of my issue so I implemented a check for that condition and when I ran the code in the debugger the browser.tabs.move function was indeed not called when moving all tabs to a new panel.

[mbnuqw]

Thank you.

canSkipMove gets the true value when you drag and drop the tab to one position down/up, so native tabs are not updated. This happens because the local state of tabs has been updated at this (line 290) moment, and the tabs[0].index has its final (as after the move) value.

We need to gather all needed info before the change of the local state of tabs:

const oneAfterAnother = tabs.every((tab, ix) => ix === 0 || tab.index === tabs[ix - 1].index + 1)
const srcIndex = tabs[0].index
// ^ Somewhere before line ~166

And check if we canSkipMove using this info (instead of 290..294):

const samePosition = srcIndex === tabs[0].index
const canSkipMove = oneAfterAnother && samePosition

[Lej77]

My bad, should have thought about the internal state updating. Anyway, I made the suggested changes and I have checked that the updated code does actually move the tabs in the native tab bar. So I think it should work now!