[MERGE] various: Make the test suite demo data independant

Purpose
=======

This is the first huge step to improve the test suite in several ways:

- Make them demo data independent, allowing to modify the demo data without having to adapt the tests depending on it. It also allows to have a beautiful + convenient demo dataset to make a demonstration, and to configure complex data in the tests to manage the corner cases.
- Improve the test performances by converting them into SavepointCase. Each test will be rollbacked to it's initial state, after the setUpClass call. That way the different data are not re-created at each test for nothing.
- Introduce several test classes in base/tests/common.py to launch a TransactionCase, HttpCase or SavepointCase test with an available demo user, portal user or a large set of partners.
- This is the first step to tend to a rolling release process, allowing to execute the tests (or a subset of the tests) on a migrated base, for example.

closes odoo/odoo#39868

Taskid: 2075739
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/addons/account_tax_python/tests/test_tax.py b/addons/account_tax_python/tests/test_tax.py
index 2ad4529cd4b..7b09d940dd2 100644
--- a/addons/account_tax_python/tests/test_tax.py
+++ b/addons/account_tax_python/tests/test_tax.py
@@ -6,10 +6,10 @@ from odoo.tests import tagged
 @tagged('post_install', '-at_install')
 class TestTaxPython(TestTax):
 
-    def setUp(self):
-        super(TestTaxPython, self).setUp()
-
-        self.python_tax = self.tax_model.create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestTaxPython, cls).setUpClass()
+        cls.python_tax = cls.tax_model.create({
             'name': 'Python TAx',
             'amount_type': 'code',
             'amount': 0.0,