test: adding inward shell (#1833)

Co-authored-by: pyansys-ci-bot <92810346+pyansys-ci-bot@users.noreply.github.com>
Co-authored-by: Roberto Pastor Muela <37798125+RobPasMue@users.noreply.github.com>

Author: 3 people

doc/changelog.d/1833.test.md

@@ -0,0 +1 @@
+adding inward shell

tests/integration/test_design.py

@@ -3111,6 +3111,12 @@ def test_shell_body(modeler: Modeler):
     assert base.volume.m == pytest.approx(Quantity(0.728, UNITS.m**3).m, rel=1e-6, abs=1e-8)
     assert len(base.faces) == 12
 
+    base = design.extrude_sketch("box", Sketch().box(Point2D([0, 0]), 1, 1), 1)
+    success = base.shell_body(-0.1)
+    assert success
+    assert base.volume.m == pytest.approx(Quantity(0.488, UNITS.m**3).m, rel=1e-6, abs=1e-8)
+    assert len(base.faces) == 12
+
 
 def test_shell_faces(modeler: Modeler):
     """Test shell commands for a single face."""