Added chamfer test file.

tests/chamfer.scad

@@ -0,0 +1,37 @@
+//
+// NopSCADlib Copyright Chris Palmer 2025
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../core.scad>
+use <../utils/chamfer.scad>
+
+module chamfer() {
+    difference() {
+        h = 1;
+        rounded_rectangle([20, 20, h], 2);
+
+        translate_z(h)
+            chamfer_hole(h + eps) {
+                circle(2);
+
+                translate([-1, 0])
+                    square([2, 5]);
+            }
+    }
+}
+
+chamfer();