[IMP] tests: scan upgrade path for additionnal tests

A future upgrades improvement will be to add tests in upgrades
modules. This small imp will scan in upgrade for some tests,
specific tooling will be added to upgrade repository in odoo/upgrade#878

closes odoo/odoo#47030

X-original-commit: 59b5a03bdf7ae1ad8851a67d278edc31a26a96a8
Signed-off-by: Xavier Dollé (xdo) <xdo@odoo.com>

odoo/modules/module.py

@@ -357,7 +357,19 @@ def get_test_modules(module):
     """ Return a list of module for the addons potentially containing tests to
     feed unittest.TestLoader.loadTestsFromModule() """
     # Try to import the module
-    modpath = 'odoo.addons.' + module
+    results = _get_tests_modules('odoo.addons', module)
+
+    try:
+        importlib.import_module('odoo.upgrade.%s' % module)
+    except ImportError:
+        pass
+    else:
+        results += _get_tests_modules('odoo.upgrade', module)
+
+    return results
+
+def _get_tests_modules(path, module):
+    modpath = '%s.%s' % (path, module)
     try:
         mod = importlib.import_module('.tests', modpath)
     except ImportError as e:  # will also catch subclass ModuleNotFoundError of P3.6