[routing] Tests for GetDistanceM method.

1 files changed, 24 insertions, 2 deletions

diff --git a/routing/routing_tests/followed_polyline_test.cpp b/routing/routing_tests/followed_polyline_test.cpp
index ab98b05661..abb7da1858 100644
--- a/routing/routing_tests/followed_polyline_test.cpp
+++ b/routing/routing_tests/followed_polyline_test.cpp
@@ -57,8 +57,30 @@ UNIT_TEST(FollowedPolylineFollowingTestByPrediction)
     MercatorBounds::RectByCenterXYAndSizeInMeters({0.002, 0.003}, 20000), dist);
   TEST_EQUAL(polyline.GetCurrentIter().m_ind, 1, ());
   TEST_LESS_OR_EQUAL(MercatorBounds::DistanceOnEarth(polyline.GetCurrentIter().m_pt,
-                                                     m2::PointD(0.003, 0.003)),
-                     0.1, ());
+                                                     m2::PointD(0.003, 0.003)), 0.1, ());
+}
+
+UNIT_TEST(FollowedPolylineDistanceCalculationTest)
+{
+  // Test full length case.
+  FollowedPolyline polyline(kTestDirectedPolyline.Begin(), kTestDirectedPolyline.End());
+  double distance = polyline.GetDistanceM(polyline.Begin(), polyline.End());
+  double masterDistance = MercatorBounds::DistanceOnEarth(kTestDirectedPolyline.Front(),
+                                                          kTestDirectedPolyline.Back());
+  ASSERT_LESS(pow(distance - masterDistance, 2), 0.001, (distance, masterDistance));
+
+  // Test partial length case.
+  polyline.UpdateProjection(MercatorBounds::RectByCenterXYAndSizeInMeters({3, 0}, 2));
+  distance = polyline.GetDistanceM(polyline.GetCurrentIter(), polyline.End());
+  masterDistance = MercatorBounds::DistanceOnEarth(kTestDirectedPolyline.GetPoint(1),
+                                                   kTestDirectedPolyline.Back());
+  ASSERT_LESS(pow(distance - masterDistance, 2), 0.001, (distance, masterDistance));
 
+  // Test point in the middle case.
+  polyline.UpdateProjection(MercatorBounds::RectByCenterXYAndSizeInMeters({4, 0}, 2));
+  distance = polyline.GetDistanceM(polyline.GetCurrentIter(), polyline.End());
+  masterDistance = MercatorBounds::DistanceOnEarth(m2::PointD(4, 0),
+                                                   kTestDirectedPolyline.Back());
+  ASSERT_LESS(pow(distance - masterDistance, 2), 0.001, (distance, masterDistance));
 }
 }  // namespace routing_test