[FIX] tests: test support for modules without `__init__.py`

Now that a test exists to enforce `__init__.py` in odoo module, we must
ensure that we keep the feature.

For that reason, a white-list system is added in `test_dunderinit` and a
test is added in order to be sure that a module without `__init__.py` can
be exists.

This this is made of a fake module `test_data_module` without
 `__init__.py` and a test module which ensure the fake module was
installed.

closes odoo/odoo#66778

X-original-commit: 506755ef
Related: odoo/enterprise#16653
Signed-off-by: Christophe Monniez (moc) <moc@odoo.com>

odoo/addons/test_data_module/__manifest__.py

+{
+    'name': 'test module to test data only modules',
+    'description': 'Fake module to test data module installation without __init__.py',
+    'version': '0.0.1',
+    'category': 'Hidden/Tests',
+    'sequence': 0,
+}

odoo/addons/test_data_module_install/__manifest__.py

+{
+    'name': 'test installation of data module',
+    'description': 'Test data module (see test_data_module) installation',
+    'version': '0.0.1',
+    'category': 'Hidden/Tests',
+    'sequence': 10,
+}

odoo/addons/test_data_module_install/tests/__init__.py

+from . import test_data_module_installed

odoo/addons/test_data_module_install/tests/test_data_module_installed.py

+# -*- coding: utf-8 -*-
+from odoo.tests import common
+
+
+class TestDataModuleInstalled(common.TransactionCase):
+    """ Test that the fake data module `test_data_module` is correctly installed.
+    The use case of this test is that odoo supports installation of data modules only without `__init__.py`.
+    """
+
+    def test_data_module_installed(self):
+
+        data_module = self.env['ir.module.module'].search([('name', '=', 'test_data_module')])
+        self.assertEqual(data_module.state, 'installed')

odoo/addons/test_lint/tests/test_dunderinit.py

@@ -9,13 +9,15 @@ from . import lint_case
 
 _logger = logging.getLogger(__name__)
 
+# whitelist that allow data modules only
+WHITELIST = ['test_data_module', ]
 
 class TestDunderinit(lint_case.LintCase):
 
     def test_dunderinit(self):
         """ Test that __init__.py exists in Odoo modules, otherwise they won't get packaged"""
 
-        modules_list = get_modules()
+        modules_list = [mod for mod in get_modules() if mod not in WHITELIST]
         for mod in modules_list:
             dunderinit_path = Path(get_module_path(mod)) / '__init__.py'
             self.assertTrue(dunderinit_path.is_file(), "Missing `__init__.py ` in module %s" % mod)