Bug fix for Tmx grouplayer (pythonarcade#648)

* Allow getting tmx layer by path

* add tests and demo

* Bug fix.  Added test for edge case also

arcade/tilemap.py

@@ -82,7 +82,8 @@ def _get_tilemap_layer(path, layers):
         for layer in layers:
             if layer.name == layer_name:
                 if isinstance(layer, pytiled_parser.objects.LayerGroup):
-                    return _get_tilemap_layer(path, layer.layers)
+                    if len(path) != 0:
+                        return _get_tilemap_layer(path, layer.layers)
                 else:
                     return layer
         return None

tests/unit2/test_tilemap_objects.py

@@ -55,6 +55,13 @@ def test_one():
     #
     assert sprite_2.alpha == int(255*.5)
 
+    #
+    # Test edge case with only group name.  Should return empty sprite list
+    #
+    tile_list_3 = arcade.tilemap.process_layer(tmx_map, "Group", base_directory="test_data")
+    assert tile_list_3 is not None
+    assert len(tile_list_3) == 0
+
     #
     # Future tests?
     #