UNT0022 changes behavior if transform is used in rotation update

[mrooney]

Hi there, it seems like UNT0022 is changing behavior and I'm wondering if this is true and if there is a way to avoid it.

To Reproduce

transform.position = Target.position + GetComputedOffset();
transform.rotation = Quaternion.LookRotation(Target.position - transform.position, Vector3.up);

Expected behavior

Nothing should be reported, because the rotation change uses the transform.position, and putting it inside SetPositionAndRotation will now cause it to use the old transform.position instead of the new one.

Actual behavior

transform.SetPositionAndRotation(Target.position + GetComputedOffset(), Quaternion.LookRotation(Target.position - transform.position, Vector3.up));

[sailro]

Hello @mrooney, this is indeed a bug.

For now and until we ship a fix, you can either disable the UNT0022 analyzer (using an .editorconfig file for example) or rewrite the code snippet with a variable:

var newPosition = Target.position + GetComputedOffset();
transform.position = newPosition;
transform.rotation = Quaternion.LookRotation(Target.position - newPosition, Vector3.up);

which is equivalent to:

var newPosition = Target.position + GetComputedOffset();
transform.SetPositionAndRotation(newPosition, Quaternion.LookRotation(Target.position - newPosition, Vector3.up));

I'm going to push a fix for that.

Thank you for reporting this !