def test_get_polygon(get_border_lonlats, Polygon):
"""Test polygon creation."""
from pyresample.gradient import get_polygon
# Valid polygon
get_border_lonlats.return_value = (1, 2)
geo_def = mock.MagicMock()
prj = mock.MagicMock()
x_borders = [0, 0, 1, 1]
y_borders = [0, 1, 1, 0]
boundary = [(0, 0), (0, 1), (1, 1), (1, 0)]
prj.return_value = (x_borders, y_borders)
poly = mock.MagicMock(area=2.0)
Polygon.return_value = poly
res = get_polygon(prj, geo_def)
get_border_lonlats.assert_called_with(geo_def)
prj.assert_called_with(1, 2)
Polygon.assert_called_with(boundary)
assert res is poly
# Some border points are invalid, those should have been removed
x_borders = [np.inf, 0, 0, 0, 1, np.nan, 2]
y_borders = [-1, 0, np.nan, 1, 1, np.nan, -1]
boundary = [(0, 0), (0, 1), (1, 1), (2, -1)]
prj.return_value = (x_borders, y_borders)
res = get_polygon(prj, geo_def)
Polygon.assert_called_with(boundary)
assert res is poly
# Polygon area is NaN
poly.area = np.nan
res = get_polygon(prj, geo_def)
assert res is None
# Polygon area is 0.0
poly.area = 0.0
res = get_polygon(prj, geo_def)
assert res is None
