add test case

test/test_in_polyline.scad

@@ -0,0 +1,31 @@
+include <in_polyline.scad>;
+
+module test_in_polyline() {
+
+
+    echo("==== test_in_polyline ====");
+    
+    pts = [
+        [0, 0],
+        [10, 0],
+        [10, 10]
+    ];
+
+    assert(!in_polyline(pts, [-2, -3]));  
+    assert(in_polyline(pts, [5, 0]));   
+    assert(in_polyline(pts, [10, 5]));   
+    assert(!in_polyline(pts, [10, 15]));  
+
+    pts2 = [
+        [10, 0, 10],
+        [20, 0, 10],
+        [20, 10, 10]
+    ]; 
+
+    assert(in_polyline(pts2, [10, 0, 10])); 
+    assert(in_polyline(pts2, [15, 0, 10])); 
+    assert(!in_polyline(pts2, [15, 1, 10]));  
+    assert(!in_polyline(pts2, [20, 11, 10]));           
+}
+
+test_in_polyline();