diff --git a/packages/cadmium/src/workbench.rs b/packages/cadmium/src/workbench.rs
index 58649e20..382a1f27 100644
--- a/packages/cadmium/src/workbench.rs
+++ b/packages/cadmium/src/workbench.rs
@@ -493,3 +493,57 @@ impl Workbench {
         realized
     }
 }
+
+#[cfg(test)]
+pub mod tests {
+    use crate::extrusion::Direction;
+
+    use super::*;
+
+    #[test]
+    fn make_empty_workbench() {
+        let wb = Workbench::new("Test Workbench");
+        assert_eq!(wb.history.len(), 4);
+        assert_eq!(wb.get_first_plane_id().unwrap(), "Plane-0".to_owned());
+        assert_eq!(wb.last_plane_id().unwrap(), "Plane-2".to_owned());
+        assert_eq!(wb.plane_name_to_id("Front").unwrap(), "Plane-0".to_owned());
+        assert_eq!(wb.plane_name_to_id("Right").unwrap(), "Plane-1".to_owned());
+        assert_eq!(wb.plane_name_to_id("Top").unwrap(), "Plane-2".to_owned());
+
+        let realization = wb.realize(1000);
+        assert_eq!(realization.points.len(), 1); //origin
+        assert_eq!(realization.planes.len(), 3); // origin, front, right, top
+        assert_eq!(realization.sketches.len(), 0);
+        assert_eq!(realization.solids.len(), 0);
+    }
+
+    #[test]
+    fn make_and_workbench_with_extrusion() {
+        let mut wb = Workbench::new("Test Workbench");
+        wb.add_sketch_to_plane("Sketch 1", "Plane-0");
+        let s = wb.get_sketch_mut("Sketch 1").unwrap();
+        let ll = s.add_point(0.0, 0.0);
+        let lr = s.add_point(40.0, 0.0);
+        let ul = s.add_point(0.0, 40.0);
+        let ur = s.add_point(40.0, 40.0);
+        s.add_segment(ll, lr);
+        s.add_segment(lr, ur);
+        s.add_segment(ur, ul);
+        s.add_segment(ul, ll);
+
+        let extrusion = Extrusion::new(
+            "Sketch-0".to_owned(),
+            vec![0],
+            25.0,
+            0.0,
+            Direction::Normal,
+            ExtrusionMode::New,
+        );
+        wb.add_extrusion("Ext1", extrusion);
+
+        let realization = wb.realize(1000);
+        assert_eq!(realization.planes.len(), 3);
+        assert_eq!(realization.sketches.len(), 1);
+        assert_eq!(realization.solids.len(), 1);
+    }
+}