[FIX] account_tax_balance: Account moves linked to bills/invoices should not be considered as refunds, unless all their lines come from refunds or their balance is negative.

account_tax_balance/models/account_move.py

@@ -2,7 +2,7 @@
 # © 2016 Antonio Espinosa <antonio.espinosa@tecnativa.com>
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from openerp import models, fields, api
+from odoo import models, fields, api
 
 
 class AccountMove(models.Model):
@@ -21,25 +21,38 @@ class AccountMove(models.Model):
     @api.multi
     @api.depends(
         'line_ids.account_id.internal_type', 'line_ids.balance',
-        'line_ids.account_id.user_type_id.type'
+        'line_ids.account_id.user_type_id.type', 'line_ids.invoice_id.type'
     )
     def _compute_move_type(self):
-        def _balance_get(line_ids, internal_type):
-            return sum(line_ids.filtered(
-                lambda x: x.account_id.internal_type == internal_type).mapped(
-                    'balance'))
+        refund_types = ('in_refund', 'out_refund')
+
+        def _is_refund(line_ids, internal_type):
+            """Check whether all the lines of type `internal_type`
+            come from a refund."""
+            line_ids = line_ids.filtered(
+                lambda x: x.account_id.internal_type == internal_type)
+            line_types = line_ids.mapped('invoice_id.type')
+            if len(line_types) == 1:
+                res = line_types[0] in refund_types
+            else:
+                # Lines are linked to invoices of different types,
+                # or to no invoice at all.
+                # If their summed balance is negative, this is a refund.
+                res = sum(line_ids.mapped('balance')) < 0
+            return res
 
         for move in self:
-            internal_types = move.line_ids.mapped('account_id.internal_type')
+            move_lines = move.line_ids
+            internal_types = move_lines.mapped('account_id.internal_type')
             if 'liquidity' in internal_types:
                 move.move_type = 'liquidity'
             elif 'payable' in internal_types:
-                balance = _balance_get(move.line_ids, 'payable')
+                is_refund = _is_refund(move_lines, 'payable')
                 move.move_type = (
-                    'payable' if balance < 0 else 'payable_refund')
+                    'payable' if not is_refund else 'payable_refund')
             elif 'receivable' in internal_types:
-                balance = _balance_get(move.line_ids, 'receivable')
+                is_refund = _is_refund(move_lines, 'receivable')
                 move.move_type = (
-                    'receivable' if balance > 0 else 'receivable_refund')
+                    'receivable' if not is_refund else 'receivable_refund')
             else:
                 move.move_type = 'other'

account_tax_balance/tests/test_account_tax_balance.py

@@ -179,3 +179,71 @@ class TestAccountTaxBalance(TransactionCase):
         tax.refresh()
         self.assertEquals(tax.base_balance, 175.)
         self.assertEquals(tax.balance, 17.5)
+
+    def test_receivable_move_type(self):
+        """
+        Receivable moves linked to invoices are not considered as refunds.
+        Also, receivable moves coming from refunds are considered as such.
+        """
+        receivable_account = self.env['account.account'].search(
+            [('user_type_id', '=', self.env.ref(
+                'account.data_account_type_receivable'
+            ).id)], limit=1)
+        invoice = self.env['account.invoice'].create({
+            'partner_id': self.env.ref('base.res_partner_2').id,
+            'account_id': receivable_account.id,
+            'type': 'out_invoice',
+            'invoice_line_ids': [(0, 0, {
+                'product_id': self.env.ref('product.product_product_4').id,
+                'account_id': receivable_account.id,
+                'quantity': 1.0,
+                'price_unit': 100.0,
+                'name': 'product that costs 100',
+            }), (0, 0, {
+                'product_id': self.env.ref('product.product_product_4').id,
+                'account_id': receivable_account.id,
+                'quantity': 1.0,
+                'price_unit': -100.0,
+                'name': 'product that costs -100',
+            })]
+        })
+        invoice.action_invoice_open()
+        self.assertEqual(invoice.move_id.move_type, 'receivable')
+
+        refund = invoice.refund()
+        refund.action_invoice_open()
+        self.assertEqual(refund.move_id.move_type, 'receivable_refund')
+
+    def test_payable_move_type(self):
+        """
+        Payable moves linked to bills are not considered as refunds.
+        Also, payable moves coming from refunds are considered as such.
+        """
+        payable_account = self.env['account.account'].search(
+            [('user_type_id', '=', self.env.ref(
+                'account.data_account_type_payable'
+            ).id)], limit=1)
+        bill = self.env['account.invoice'].create({
+            'partner_id': self.env.ref('base.res_partner_2').id,
+            'account_id': payable_account.id,
+            'type': 'in_invoice',
+            'invoice_line_ids': [(0, 0, {
+                'product_id': self.env.ref('product.product_product_4').id,
+                'account_id': payable_account.id,
+                'quantity': 1.0,
+                'price_unit': 100.0,
+                'name': 'product that costs 100',
+            }), (0, 0, {
+                'product_id': self.env.ref('product.product_product_4').id,
+                'account_id': payable_account.id,
+                'quantity': 1.0,
+                'price_unit': -100.0,
+                'name': 'product that costs -100',
+            })]
+        })
+        bill.action_invoice_open()
+        self.assertEqual(bill.move_id.move_type, 'payable')
+
+        refund = bill.refund()
+        refund.action_invoice_open()
+        self.assertEqual(refund.move_id.move_type, 'payable_refund')