testing the copy, deepcopy, serialize etc. of Repeat with thickness C…

…alculation intact

tests/refl1d/stack_test.py

@@ -34,3 +34,36 @@ def test_stack_serialization():
     assert thickness_plus.value == 160
     sample[0].thickness.value += 40
     assert thickness_plus.value == 200
+
+
+def test_repeat_serialization():
+    """test that stack can be serialized and deserialized with all the methods we use,
+    preserving the functioning of the Calculation object for the total thickness"""
+    unit_cell = Slab(SLD(rho=10), thickness=10) | Slab(SLD(rho=10), thickness=20) | Slab(SLD(rho=10), thickness=30)
+    # This creates a Repeat object from the Stack:
+    sample = unit_cell * 4
+    thickness_plus = sample.thickness + 100  # expression
+
+    ser_t, ser_s = deserialize(serialize([thickness_plus, sample]))
+    assert ser_t.value == 340  # (10+20+30 * 4) + 100
+    ser_s.stack[0].thickness.value += 40
+    assert ser_t.value == 500  # (50+20+30 * 4) + 100
+
+    dc_t, dc_s = deepcopy([thickness_plus, sample])
+    assert dc_t.value == 340
+    dc_s.stack[0].thickness.value += 40
+    assert dc_t.value == 500
+
+    pickle_t, pickle_s = pickle.loads(pickle.dumps([thickness_plus, sample]))
+    assert pickle_t.value == 340
+    pickle_s.stack[0].thickness.value += 40
+    assert pickle_t.value == 500
+
+    dill_t, dill_s = dill.loads(dill.dumps([thickness_plus, sample]))
+    assert dill_t.value == 340
+    dill_s.stack[0].thickness.value += 40
+    assert dill_t.value == 500
+
+    assert thickness_plus.value == 340
+    sample.stack[0].thickness.value += 40
+    assert thickness_plus.value == 500