Added a unittest as requested.

account_reversal/tests/__init__.py

@@ -0,0 +1,23 @@
+# -*- encoding: utf-8 -*-
+##############################################################################
+#
+#    Account partner required module for OpenERP
+#    Copyright (C) 2014 Acsone (http://acsone.eu).
+#    @author Stéphane Bidoul <stephane.bidoul@acsone.eu>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from . import test_account_reversal

account_reversal/tests/test_account_reversal.py

@@ -0,0 +1,101 @@
+# -*- encoding: utf-8 -*-
+# #############################################################################
+#
+# Account partner required module for OpenERP
+#    Copyright (C) 2014 Acsone (http://acsone.eu).
+#    @author Stéphane Bidoul <stephane.bidoul@acsone.eu>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from openerp.tests import common
+from openerp import fields
+from datetime import datetime
+
+
+class test_account_reversal(common.TransactionCase):
+
+    def setUp(self):
+        super(test_account_reversal, self).setUp()
+        self.move_obj = self.env['account.move']
+        self.move_line_obj = self.env['account.move.line']
+
+    def _create_move(self, with_partner, amount=100):
+        date = datetime.now()
+        company_id = self.env.ref('base.main_company').id
+        period_id = self.env['account.period'].with_context(
+            account_period_prefer_normal=True,
+            company_id=self.env.ref('base.main_company').id).find(date)[0]
+
+        journal = self.env['account.journal'].create({
+            'name': 'Test journal',
+            'code': 'COD',
+            'type': 'sale',
+            'sequence_id': self.env.ref('account.sequence_sale_journal').id,
+            'company_id': company_id})
+
+        move_vals = {
+            'journal_id': journal.id,
+            'period_id': period_id.id,
+            'date': date,
+            'company_id': company_id,
+        }
+
+        # Why this doesn't work I don't know:
+        # acct = self.ref('account.a_sale'
+        account1, account2 = self.env['account.account'].search(
+            [('company_id', '=', company_id), ('type', '=', 'other')])[:2]
+
+        move_id = self.move_obj.create(move_vals)
+        self.move_line_obj.create({
+            'move_id': move_id.id,
+            'name': '/',
+            'debit': 0,
+            'credit': amount,
+            'company_id': company_id,
+            'account_id': account1.id})
+        move_line_id = self.move_line_obj.create(
+            {
+                'move_id': move_id.id,
+                'name': '/',
+                'debit': amount,
+                'credit': 0,
+                'account_id': account2.id,
+                'company_id': company_id,
+                'partner_id': self.ref('base.res_partner_1')
+                if with_partner else False
+            }
+        )
+        return move_line_id
+
+    def test_reverse(self):
+        move_line = self._create_move(with_partner=False)
+        move = move_line.move_id
+        company_id = self.env.ref('base.main_company').id
+        account1 = self.env['account.account'].search(
+            [('company_id', '=', company_id), ('type', '=', 'other')])[0]
+        movestr = ''.join(['%.2f%.2f%s' % (x.debit, x.credit,
+                                           x.account_id == account1 and
+                                           'aaaa' or 'bbbb')
+                           for x in move.line_id])
+        self.assertEqual(movestr, '100.000.00bbbb0.00100.00aaaa')
+        yesterday_date = datetime(year=2015, month=3, day=3)
+        yesterday = fields.Date.to_string(yesterday_date)
+        reversed_move = move.create_reversals(yesterday)
+        movestr_reversed = ''.join(
+            ['%.2f%.2f%s' % (x.debit, x.credit,
+                             x.account_id == account1 and 'aaaa' or 'bbbb')
+             for x in reversed_move.line_id])
+        self.assertEqual(movestr_reversed, '0.00100.00bbbb100.000.00aaaa')