import unittest
from shapely.geometry import LineString, Polygon
from shapely.ops import snap
class Snap(unittest.TestCase):
def test_snap(self):
# input geometries
square = Polygon([(1, 1), (2, 1), (2, 2), (1, 2), (1, 1)])
line = LineString([(0, 0), (0.8, 0.8), (1.8, 0.95), (2.6, 0.5)])
square_coords = square.exterior.coords[:]
line_coords = line.coords[:]
result = snap(line, square, 0.5)
# test result is correct
assert isinstance(result, LineString)
assert result.coords[:] == [(0.0, 0.0), (1.0, 1.0), (2.0, 1.0), (2.6, 0.5)]
# test inputs have not been modified
assert square.exterior.coords[:] == square_coords
assert line.coords[:] == line_coords