Show cost allocation before and after posting

issue11558
review413301003

account.py

@@ -14,11 +14,11 @@ class ShipmentCost(metaclass=PoolMeta):
         cls.allocation_method.selection.append(('weight', "By Weight"))
 
     def allocate_cost_by_weight(self):
-        self.factors = self._get_weight_factors()
+        self.factors = self._get_factors('weight')
         self._allocate_cost(self.factors)
 
     def unallocate_cost_by_weight(self):
-        factors = self.factors or self._get_weight_factors()
+        factors = self.factors or self._get_factors('weight')
         self._allocate_cost(factors, sign=-1)
 
     def _get_weight_factors(self):

tests/scenario_account_stock_shipment_cost_weight.rst

@@ -149,7 +149,12 @@ Add shipment cost to both shipments::
     >>> shipment_cost.save()
     >>> shipment_cost.state
     'draft'
-    >>> shipment_cost.click('post')
+    >>> post_shipment_cost = Wizard('account.shipment_cost.post', [shipment_cost])
+    >>> post_shipment_cost.form.cost
+    Decimal('20.0000')
+    >>> sorted([s.cost for s in post_shipment_cost.form.shipments])
+    [Decimal('5.0000'), Decimal('15.0000')]
+    >>> post_shipment_cost.execute('post')
     >>> shipment_cost.state
     'posted'
     >>> bool(shipment_cost.posted_date)