storage_image_product: ease test setup for other modules

Having a mixin class allows to run the setup of the base data explicitly where needed
especially when you have test classes with multiple inheritances.

After the Odoo tests apocalypse we cannot rely anymore on running Klass.setUpClass()
w/o tons of attributes warning. Now you can inherit the mixin and do the setup properly.

Author: simahawk

storage_image_product/tests/common.py

@@ -8,7 +8,7 @@
 from odoo.addons.component.tests.common import TransactionComponentCase
 
 
-class ProductImageCommonCase(TransactionComponentCase):
+class ProductImageCaseMixin:
     @staticmethod
     def _get_file_content(name, base_path=None, as_binary=False):
         path = base_path or os.path.dirname(os.path.abspath(__file__))
@@ -25,12 +25,18 @@ def _create_storage_image(cls, name):
         )
 
     @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
+    def _setup_base_image_data(cls):
         cls.template = cls.env.ref("product.product_product_4_product_template")
         cls.product_a = cls.env.ref("product.product_product_4")
         cls.product_b = cls.env.ref("product.product_product_4b")
         cls.product_c = cls.env.ref("product.product_product_4c")
         cls.logo_image = cls._create_storage_image("logo-image.jpg")
         cls.white_image = cls._create_storage_image("white-image.jpg")
         cls.black_image = cls._create_storage_image("black-image.jpg")
+
+
+class ProductImageCommonCase(TransactionComponentCase, ProductImageCaseMixin):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls._setup_base_image_data()