show boolean option value to yes/no in stead of true/false (#4005)

* show boolean option value to yes/no in stead of true/false

* remove brackets

* add unit test

Co-authored-by: Wai Law <jan@uwkm.nl>

src/oscar/apps/catalogue/abstract_models.py

         """
         return str(self.value)
 
+    @property
+    def _boolean_as_text(self):
+        if self.value:
+            return _("Yes")
+        return _("No")
+
     @property
     def value_as_html(self):
         """

tests/integration/catalogue/test_attributes.py

         with self.assertRaises(ValidationError):
             self.attr.validate_value(1)
 
+    def test_boolean_value_as_text_true(self):
+        product = factories.ProductFactory()
+        self.attr.save_value(product, True)
+        attr_val = product.attribute_values.get(attribute=self.attr)
+        assert attr_val.value_as_text == "Yes"
+
+    def test_boolean_value_as_text_false(self):
+        product = factories.ProductFactory()
+        self.attr.save_value(product, False)
+        attr_val = product.attribute_values.get(attribute=self.attr)
+        assert attr_val.value_as_text == "No"
+
+
 
 class TestMultiOptionAttributes(TestCase):