Steps to reproduce :

- import the project attached
- open the ControllerTester scene
- press right to attempt to climb the ramp and notice that the normal is reported as -1,0

Explanation :
Both the line-cast and ray-cast for 2D return colliders that exist at the start of the line/ray. This differs from 3D which doesn't do that.

In the case of something found at fraction=0 i.e. the start of the line/ray, it indicates that the line/ray starts inside a collider. In this case there is no collision normal as the line/ray did not intersect any surface.

Under these circumstances, rather than return a zero collision normal, the collision normal is set to be the opposite of the line/ray vector.

It should be note that the example provided moves the character around by manipulating the transform and bypasses the 2D physics itself. This causes interpenetration. In the example project, if I ignore hits at fraction=0 then the character simply falls through the levels.