diff --git a/src/test/java/com/williamfiset/algorithms/geometry/LineSegmentLineSegmentIntersectionTest.java b/src/test/java/com/williamfiset/algorithms/geometry/LineSegmentLineSegmentIntersectionTest.java
new file mode 100644
index 000000000..8cd4120b0
--- /dev/null
+++ b/src/test/java/com/williamfiset/algorithms/geometry/LineSegmentLineSegmentIntersectionTest.java
@@ -0,0 +1,266 @@
+package com.williamfiset.algorithms.geometry;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.williamfiset.algorithms.geometry.LineSegmentLineSegmentIntersection.lineSegmentLineSegmentIntersection;
+
+import org.junit.*;
+
+public class LineSegmentLineSegmentIntersectionTest {
+
+    @Test
+    public void testFromMain() {
+        // ¨test cases¨ from main
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        p1 = new LineSegmentLineSegmentIntersection.Pt(-2, 4);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(3, 3);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(2, 4);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        LineSegmentLineSegmentIntersection.Pt point = points[0];
+
+        // point: (1.636, 3.273)
+        assertThat(point.x ).isEqualTo(1.6363636363636362);
+        assertThat(point.y).isEqualTo(3.2727272727272725);
+
+        p1 = new LineSegmentLineSegmentIntersection.Pt(-10, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(+10, 0);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(-5, 0);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(+5, 0);
+        points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        LineSegmentLineSegmentIntersection.Pt point1 = points[0], point2 = points[1];
+
+        // point1: (-5.000, 0.000), point2: (5.000, 0.000)
+        assertThat(point1.x).isEqualTo(-5.0);
+        assertThat(point1.y).isEqualTo(0.0);
+        assertThat(point2.x).isEqualTo(5.0);
+        assertThat(point2.y).isEqualTo(0.0);
+    }
+
+    @Test
+    public void testNoSegmentsIntersect() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make the segments parallel -> no intersection
+        p1 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(0, 1);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(1, 1);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+
+        // no intersection exists
+        assertThat(points.length).isEqualTo(0);
+    }
+
+    @Test
+    public void testSegmentsEqualSamePoint() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make the segments the same point
+        p1 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // only one solution; (0.0)
+        assertThat(points.length).isEqualTo(1);
+
+        LineSegmentLineSegmentIntersection.Pt point = points[0];
+
+        // point: (0, 0)
+        assertThat(point.x).isEqualTo(0.0);
+        assertThat(point.y).isEqualTo(0.0);
+    }
+
+    @Test
+    public void testOneSegmentIsIntersectingPoint() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make segment #2 as a point and place at the endpoint of #1
+        p1 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // one solution; (1,4)
+        assertThat(points.length).isEqualTo(1);
+
+        LineSegmentLineSegmentIntersection.Pt point = points[0];
+
+        assertThat(point.x).isEqualTo(1.0);
+        assertThat(point.y).isEqualTo(4.0);
+
+        // make segment #1 as a point and place at the endpoint of #2
+        p1 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // one solution; (1,4)
+        assertThat(points.length).isEqualTo(1);
+
+        point = points[0];
+
+        assertThat(point.x).isEqualTo(1.0);
+        assertThat(point.y).isEqualTo(4.0);
+    }
+
+    @Test
+    public void testSegmentsAreEqual() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make the segments equal
+        p1 = new LineSegmentLineSegmentIntersection.Pt(1, 1);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(2, 2);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(1, 1);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(2, 2);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // two solutions; (1,1) and (2.2)
+        assertThat(points.length).isEqualTo(2);
+
+        LineSegmentLineSegmentIntersection.Pt point1 = points[0];
+        LineSegmentLineSegmentIntersection.Pt point2 = points[1];
+
+        assertThat(point1.x).isEqualTo(1.0);
+        assertThat(point1.y).isEqualTo(1.0);
+        assertThat(point2.x).isEqualTo(2.0);
+        assertThat(point2.y).isEqualTo(2.0);
+    }
+
+    @Test
+    public void testOneSegmentEnclosedInTheOther() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // put segment #2 in segment #1
+        p1 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(1, 2);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(1, 3);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // two solutions; p3 and p4
+        assertThat(points.length).isEqualTo(2);
+
+        LineSegmentLineSegmentIntersection.Pt point1 = points[0];
+        LineSegmentLineSegmentIntersection.Pt point2 = points[1];
+
+        assertThat(point1.x).isEqualTo(p3.x);
+        assertThat(point1.y).isEqualTo(p3.y);
+        assertThat(point2.x).isEqualTo(p4.x);
+        assertThat(point2.y).isEqualTo(p4.y);
+
+        // put segment #1 in segment #2
+        p1 = new LineSegmentLineSegmentIntersection.Pt(1, 2);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(1, 3);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // two solutions; p1 and p2
+        assertThat(points.length).isEqualTo(2);
+
+        point1 = points[0];
+        point2 = points[1];
+
+        assertThat(point1.x).isEqualTo(p1.x);
+        assertThat(point1.y).isEqualTo(p1.y);
+        assertThat(point2.x).isEqualTo(p2.x);
+        assertThat(point2.y).isEqualTo(p2.y);
+    }
+
+    @Test
+    public void testCollinearSegments() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make the segments collinear but one doesn't enclose the other
+        p1 = new LineSegmentLineSegmentIntersection.Pt(0, 1);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(4, 1);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(3, 1);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(7, 1);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // two solutions; p3 and p2
+        assertThat(points.length).isEqualTo(2);
+
+        LineSegmentLineSegmentIntersection.Pt point1 = points[0];
+        LineSegmentLineSegmentIntersection.Pt point2 = points[1];
+
+        assertThat(point1.x).isEqualTo(p3.x);
+        assertThat(point1.y).isEqualTo(p3.y);
+        assertThat(point2.x).isEqualTo(p2.x);
+        assertThat(point2.y).isEqualTo(p2.y);
+
+        // make the segments collinear but start #2 where #1 ends
+        p1 = new LineSegmentLineSegmentIntersection.Pt(0, 1);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(4, 1);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(4, 1);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(7, 1);
+        points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // one solution; p2 = p3
+        assertThat(points.length).isEqualTo(1);
+
+        point1 = points[0];
+
+        assertThat(point1.x).isEqualTo(p2.x);
+        assertThat(point1.y).isEqualTo(p2.y);
+    }
+
+    @Test
+    public void testOneSegmentIsVertical() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make segment #1 vertical and #2 horizontal
+        p1 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(0, 2);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(4, 2);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // one solution; (1,2)
+        assertThat(points.length).isEqualTo(1);
+
+        LineSegmentLineSegmentIntersection.Pt point = points[0];
+
+        assertThat(point.x).isEqualTo(1.0);
+        assertThat(point.y).isEqualTo(2.0);
+
+
+        // make segment #2 vertical and #2 horizontal
+        p1 = new LineSegmentLineSegmentIntersection.Pt(0, 2);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(4, 2);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(1, 0);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(1, 4);
+        points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // one solution; (1,2)
+        assertThat(points.length).isEqualTo(1);
+
+        point = points[0];
+
+        assertThat(point.x).isEqualTo(1.0);
+        assertThat(point.y).isEqualTo(2.0);
+    }
+
+    @Test
+    public void testUniqueIntersectionPoint() {
+        // Segment #1 is (p1, p2), segment #2 is (p3, p4)
+        LineSegmentLineSegmentIntersection.Pt p1, p2, p3, p4;
+
+        // make segment #1 and #2 cross like an X
+        p1 = new LineSegmentLineSegmentIntersection.Pt(0, 0);
+        p2 = new LineSegmentLineSegmentIntersection.Pt(4, 4);
+        p3 = new LineSegmentLineSegmentIntersection.Pt(0, 4);
+        p4 = new LineSegmentLineSegmentIntersection.Pt(4, 0);
+        LineSegmentLineSegmentIntersection.Pt[] points = lineSegmentLineSegmentIntersection(p1, p2, p3, p4);
+        // one solution; (2,2)
+        assertThat(points.length).isEqualTo(1);
+
+        LineSegmentLineSegmentIntersection.Pt point = points[0];
+
+        assertThat(point.x).isEqualTo(2.0);
+        assertThat(point.y).isEqualTo(2.0);
+    }
+}