Fixed #29770 -- Added LinearRing.is_counterclockwise property.

1 files changed, 27 insertions, 1 deletions

diff --git a/tests/gis_tests/geos_tests/test_geos.py b/tests/gis_tests/geos_tests/test_geos.py
index a74eabb314..c2aca95178 100644
--- a/tests/gis_tests/geos_tests/test_geos.py
+++ b/tests/gis_tests/geos_tests/test_geos.py
@@ -5,7 +5,7 @@ import pickle
 import random
 from binascii import a2b_hex
 from io import BytesIO
-from unittest import mock
+from unittest import mock, skipIf
 
 from django.contrib.gis import gdal
 from django.contrib.gis.geos import (
@@ -360,6 +360,32 @@ class GEOSTest(SimpleTestCase, TestDataMixin):
         line.reverse()
         self.assertEqual(line.ewkt, 'SRID=4326;LINESTRING (151.2607 -33.887, 144.963 -37.8143)')
 
+    def _test_is_counterclockwise(self):
+        lr = LinearRing((0, 0), (1, 0), (0, 1), (0, 0))
+        self.assertIs(lr.is_counterclockwise, True)
+        lr.reverse()
+        self.assertIs(lr.is_counterclockwise, False)
+        msg = 'Orientation of an empty LinearRing cannot be determined.'
+        with self.assertRaisesMessage(ValueError, msg):
+            LinearRing().is_counterclockwise
+
+    @skipIf(geos_version_tuple() < (3, 7), 'GEOS >= 3.7.0 is required')
+    def test_is_counterclockwise(self):
+        self._test_is_counterclockwise()
+
+    @skipIf(geos_version_tuple() < (3, 7), 'GEOS >= 3.7.0 is required')
+    def test_is_counterclockwise_geos_error(self):
+        with mock.patch('django.contrib.gis.geos.prototypes.cs_is_ccw') as mocked:
+            mocked.return_value = 0
+            mocked.func_name = 'GEOSCoordSeq_isCCW'
+            msg = 'Error encountered in GEOS C function "GEOSCoordSeq_isCCW".'
+            with self.assertRaisesMessage(GEOSException, msg):
+                LinearRing((0, 0), (1, 0), (0, 1), (0, 0)).is_counterclockwise
+
+    @mock.patch('django.contrib.gis.geos.libgeos.geos_version', lambda: b'3.6.9')
+    def test_is_counterclockwise_fallback(self):
+        self._test_is_counterclockwise()
+
     def test_multilinestring(self):
         "Testing MultiLineString objects."
         prev = fromstr('POINT(0 0)')