[FIX] account_asset: first depreciation amount

When an asset is set as Prorata Temporis, with a one month period, the
first depreciation amount is computed on the basis of the remaining days
in the purchase year. This doesn't make sense for a monthly
depreciation.

This commit makes the distinction between a monthly and a yearly
depreciation. In the case of a monthly depreciation, the remaining days
in the purchase month are taken into account.

opw-690034

addons/account_asset/account_asset.py

@@ -1,12 +1,13 @@
 # -*- coding: utf-8 -*-
 
+import calendar
 from datetime import date, datetime
 from dateutil.relativedelta import relativedelta
 
 from openerp import api, fields, models, _
 from openerp.exceptions import UserError, ValidationError
 from openerp.tools import DEFAULT_SERVER_DATE_FORMAT as DF
-from openerp.tools import float_compare
+from openerp.tools import float_compare, float_is_zero
 
 
 class AccountAssetCategory(models.Model):
@@ -129,14 +130,26 @@ class AccountAssetAsset(models.Model):
                 if self.prorata:
                     amount = amount_to_depr / self.method_number
                     if sequence == 1:
-                        days = (self.company_id.compute_fiscalyear_dates(depreciation_date)['date_to'] - depreciation_date).days + 1
-                        amount = (amount_to_depr / self.method_number) / total_days * days
+                        if self.method_period % 12 != 0:
+                            date = datetime.strptime(self.date, '%Y-%m-%d')
+                            month_days = calendar.monthrange(date.year, date.month)[1]
+                            days = month_days - date.day + 1
+                            amount = (amount_to_depr / self.method_number) / month_days * days
+                        else:
+                            days = (self.company_id.compute_fiscalyear_dates(depreciation_date)['date_to'] - depreciation_date).days + 1
+                            amount = (amount_to_depr / self.method_number) / total_days * days
             elif self.method == 'degressive':
                 amount = residual_amount * self.method_progress_factor
                 if self.prorata:
                     if sequence == 1:
-                        days = (self.company_id.compute_fiscalyear_dates(depreciation_date)['date_to'] - depreciation_date).days + 1
-                        amount = (residual_amount * self.method_progress_factor) / total_days * days
+                        if self.method_period % 12 != 0:
+                            date = datetime.strptime(self.date, '%Y-%m-%d')
+                            month_days = calendar.monthrange(date.year, date.month)[1]
+                            days = month_days - date.day + 1
+                            amount = (residual_amount * self.method_progress_factor) / month_days * days
+                        else:
+                            days = (self.company_id.compute_fiscalyear_dates(depreciation_date)['date_to'] - depreciation_date).days + 1
+                            amount = (residual_amount * self.method_progress_factor) / total_days * days
         return amount
 
     def _compute_board_undone_dotation_nb(self, depreciation_date, total_days):
@@ -189,6 +202,8 @@ class AccountAssetAsset(models.Model):
                 sequence = x + 1
                 amount = self._compute_board_amount(sequence, residual_amount, amount_to_depr, undone_dotation_number, posted_depreciation_line_ids, total_days, depreciation_date)
                 amount = self.currency_id.round(amount)
+                if float_is_zero(amount, precision_rounding=self.currency_id.rounding):
+                    continue
                 residual_amount -= amount
                 vals = {
                     'amount': amount,

addons/account_asset/tests/test_account_asset.py

@@ -61,7 +61,7 @@ class TestAccountAsset(common.TransactionCase):
         asset_modify_number_0.with_context({'active_id': account_asset_asset_office0.id}).modify()
 
         # I check the proper depreciation lines created.
-        self.assertEqual(account_asset_asset_office0.method_number, len(account_asset_asset_office0.depreciation_line_ids) - 1)
+        self.assertEqual(account_asset_asset_office0.method_number, len(account_asset_asset_office0.depreciation_line_ids))
         # I compute a asset on period.
 
         context = {