from matrixmania.compute import rot_2D
import math

def test_rot_2D_identity():
    """Rotation by 0 radians should return identity matrix"""
    result = rot_2D(0)
    expected = [[1, 0], [0, 1]]
    assert all(abs(result[i][j] - expected[i][j]) < 1e-9 for i in range(2) for j in range(2))

def test_rot_2D_90_degrees():
    """Rotation by 90° (pi/2 radians)"""
    result = rot_2D(math.pi / 2)
    expected = [[0, -1], [1, 0]]
    assert all(abs(result[i][j] - expected[i][j]) < 1e-9 for i in range(2) for j in range(2))

def test_rot_2D_180_degrees():
    """Rotation by 180° (pi radians)"""
    result = rot_2D(math.pi)
    expected = [[-1, 0], [0, -1]]
    assert all(abs(result[i][j] - expected[i][j]) < 1e-9 for i in range(2) for j in range(2))