updade from Atlas repo

25-class-metaprog/metabunch/from3.6/bunch_test.py

@@ -0,0 +1,59 @@
+import pytest
+
+from bunch import Bunch
+
+class Point(Bunch):
+    """ A point has x and y coordinates, defaulting to 0.0,
+        and a color, defaulting to 'gray'—and nothing more,
+        except what Python and the metaclass conspire to add,
+        such as __init__ and __repr__
+    """
+    x = 0.0
+    y = 0.0
+    color = 'gray'
+
+
+def test_init_defaults():
+    p = Point()
+    assert repr(p) == 'Point()'
+
+
+def test_init():
+    p = Point(x=1.2, y=3.4, color='red')
+    assert repr(p) == "Point(x=1.2, y=3.4, color='red')"
+
+
+def test_init_wrong_argument():
+    with pytest.raises(AttributeError) as exc:
+        p = Point(x=1.2, y=3.4, flavor='coffee')
+    assert "no attribute 'flavor'" in str(exc.value)
+
+
+def test_slots():
+    p = Point()
+    with pytest.raises(AttributeError) as exc:
+        p.z = 5.6
+    assert "no attribute 'z'" in str(exc.value)
+
+
+def test_dunder_permitted():
+    class Cat(Bunch):
+        name = ''
+        weight = 0
+
+        def __str__(self):
+            return f'{self.name} ({self.weight} kg)'
+
+    cheshire = Cat(name='Cheshire')
+    assert str(cheshire) == 'Cheshire (0 kg)'
+
+
+def test_dunder_forbidden():
+    with pytest.raises(AttributeError) as exc:
+        class Cat(Bunch):
+            name = ''
+            weight = 0
+
+            def __init__(self):
+                pass
+    assert "Can't set '__init__' in 'Cat'" in str(exc.value)