3.4~ as they were preparing early 4.0 releases was when I was experimenting with godot.
I should add that I was specifically trying to use c# ecosystem for godot at the time and their plugins for testing. Since I ended up with Unreal I'm refreshed enough in c++ that I might check Godot 4.0 out this weekend again.
When I was moving away from Unity I looked at Godot and really liked it. It's nowhere near as performant or feature rich as other engines and it's future is undecided but it was fun to tinker with and get things moving. I hope to return to it in the future.
The lack of easy testing made me not use it. There were a couple testing plugins users had made which could kind of do unit and integration testing but they were super finicky.
I should add that I was specifically trying to use c# ecosystem for godot at the time and their plugins for testing. Since I ended up with Unreal I'm refreshed enough in c++ that I might check Godot 4.0 out this weekend again.