test: fix testcases to test number of intersections

Author: f-frhs

src/Spatial.Tests/Euclidean/Circle2DTests.cs

@@ -1,4 +1,5 @@
-using System;
+using System;
+using System.Linq;
 using MathNet.Spatial.Euclidean;
 using NUnit.Framework;
 
@@ -59,19 +60,19 @@ public void CircleFromThreePointsArgumentException()
             Assert.Throws<ArgumentException>(() => { Circle2D.FromPoints(p1, p2, p3); });
         }
 
-        [TestCase("0,0", 1.41421356 /*=sqrt(2)*/, "-1,-1", "+1,+1", "+1,+1", "-1,-1")]
-        [TestCase("0,0", 1, "-1,0", "+1,0", "+1,0", "-1,0")]
-        [TestCase("0,0", 1, "0,-1", "0,+1", "0,+1", "0,-1")]
-        public void CircleIntersectWithLine2D(string sc, double radius, string sps, string spe, string esp0, string esp1)
+        [TestCase("0,0", 1, "-10,+10", "+10,+10", 0)]
+        [TestCase("0,0", 1, "-10,+1", "+10,+1", 1)]
+        [TestCase("0,0", 1, "-10,0", "+10,0", 2)]
+        [TestCase("0,0", 1, "-10,-1", "+10,-1", 1 )]
+        [TestCase("0,0", 1, "-10,-10", "+10,-10", 0)]
+        public void CircleIntersectWithLine2D_NumberOfIntersections(string sc, double radius, string sps, string spe, int expectedNumberOfIntersections)
         {
             var circle = new Circle2D(Point2D.Parse(sc), radius);
             var line = new Line2D(Point2D.Parse(sps), Point2D.Parse(spe));
+
             var actual = circle.IntersectWith(line);
-            Assert.That(actual.Length, Is.EqualTo(2));
 
-            var expected = new[] { Point2D.Parse(esp0), Point2D.Parse(esp1) };
-            AssertGeometry.AreEqual(actual[0], expected[0]);
-            AssertGeometry.AreEqual(actual[1], expected[1]);
+            Assert.That(actual.Count(), Is.EqualTo(expectedNumberOfIntersections));
         }
 
         [TestCase("0,0", 1.41421356 /*=sqrt(2)*/, "0,0", "+1,+1", "+1,+1")]