Improve test coverage of Plotter.add_floor (#4866)

* Improve test coverage of Plotter.add_floor

* Update renderer.py

* Apply suggestions from code review

* Update test_plotter.py

* Update test_plotter.py

pyvista/plotting/renderer.py

@@ -1948,7 +1948,7 @@ def add_floor(
             i_size = ranges[2]
             j_size = ranges[1]
         else:
-            raise NotImplementedError(f'Face ({face}) not implementd')
+            raise NotImplementedError(f'Face ({face}) not implemented')
         self._floor = pyvista.Plane(
             center=center,
             direction=normal,

tests/plotting/test_plotter.py

@@ -402,3 +402,26 @@ def test_plotter_meshes(sphere, cube):
     assert sphere in pl.meshes
     assert cube in pl.meshes
     assert len(pl.meshes) == 2
+
+
+@pytest.mark.parametrize(
+    'face, normal',
+    [
+        ('-Z', (0, 0, 1)),
+        ('-Y', (0, 1, 0)),
+        ('-X', (1, 0, 0)),
+        ('+Z', (0, 0, -1)),
+        ('+Y', (0, -1, 0)),
+        ('+X', (-1, 0, 0)),
+    ],
+)
+def test_plotter_add_floor(face, normal):
+    pl = pv.Plotter()
+    pl.add_floor(face=face)
+    assert np.allclose(pl.renderer._floor.face_normals[0], normal)
+
+
+def test_plotter_add_floor_raise_error():
+    pl = pv.Plotter()
+    with pytest.raises(NotImplementedError, match='not implemented'):
+        pl.add_floor(face='invalid')