diff --git a/Makefile b/Makefile
index 3c3f1ef..e5dd299 100644
--- a/Makefile
+++ b/Makefile
@@ -12,5 +12,5 @@ help:
 	@echo "  coverage to run coverage check of the source files."
 
 coverage:
-	coverage run --source='gwift' gwift/manage.py test; coverage report; coverage html;
+	coverage run --source='.' src/manage.py test; coverage report; coverage html;
 	@echo "Testing of coverage in the sources finished."
\ No newline at end of file
diff --git a/src/wish/models.py b/src/wish/models.py
index e31c309..f7b54be 100644
--- a/src/wish/models.py
+++ b/src/wish/models.py
@@ -14,7 +14,7 @@ class AbstractModel(models.Model):
 class UnknownUser(models.Model):
 
     name = models.CharField(max_length=255)
-    email = models.CharField(max_length=255)
+    email = models.CharField(max_length=255, unique=True)
 
 class Wishlist(AbstractModel):
 
@@ -22,14 +22,6 @@ class Wishlist(AbstractModel):
     description = models.TextField()
     external_id = models.UUIDField(unique=True, default=uuid.uuid4, editable=False)
 
-    @staticmethod
-    def create(name, description):
-        w = Wishlist()
-        w.name = name
-        w.description = description
-        w.save()
-        return w
-
 
 class Wish(AbstractModel):
 
@@ -42,31 +34,20 @@ class Wish(AbstractModel):
     estimated_price = models.DecimalField(max_digits=19, decimal_places=2,
                                           null=True)
 
-    @staticmethod
-    def create(name, description, wishlist):
-        i = Wish()
-        i.name = name
-        i.description = description
-        i.wishlist = wishlist
-        i.save()
-        return i
-
     @property
-    def percentage(self):
+    def percentage_of_completion(self):
         """
         Calcule le pourcentage de complétion pour un élément.
         """
-        number_of_linked_parts = Part.objects.filter(wish=self).count()
+        number_of_linked_parts = WishPart.objects.filter(wish=self).count()
         total = self.number_of_parts * self.numbers_available
         percentage = (number_of_linked_parts / total)
         return percentage * 100
 
 class WishPart(models.Model):
-    wish = models.ForeignKey(Wish)
-    user = models.ForeignKey(User)
-    unknown_user = models.ForeignKey('UnknownUser')
-    comment = models.TextField()
-    done_at = models.DateTimeField()
 
-    def save(self, force_insert=False, force_update=False, commit=True):
-        pass
+    wish = models.ForeignKey(Wish)
+    user = models.ForeignKey(User, null=True)
+    unknown_user = models.ForeignKey('UnknownUser', null=True)
+    comment = models.TextField(null=True, blank=True)
+    done_at = models.DateTimeField(auto_now_add=True)
diff --git a/src/wish/tests.py b/src/wish/tests.py
index 7ce503c..a0e9a7f 100644
--- a/src/wish/tests.py
+++ b/src/wish/tests.py
@@ -1,3 +1,35 @@
 from django.test import TestCase
 
-# Create your tests here.
+from .models import Wishlist, Wish, WishPart
+
+class TestWishModel(TestCase):
+    def test_percentage_of_completion(self):
+        """
+        Vérifie que le pourcentage de complétion d'un souhait 
+        est correctement calculé.
+        """
+        wishlist = Wishlist(name='Fake WishList', 
+                            description='This is a faked wishlist')
+        wishlist.save()
+               
+        wish = Wish(wishlist=wishlist, 
+                    name='Fake Wish', 
+                    description='This is a faked wish',
+                    number_of_parts=4)
+        wish.save()
+        
+        part1 = WishPart(wish=wish, comment='part1')
+        part1.save()
+        self.assertEqual(25, wish.percentage_of_completion)
+        
+        part2 = WishPart(wish=wish, comment='part2')
+        part2.save()
+        self.assertEqual(50, wish.percentage_of_completion)
+        
+        part3 = WishPart(wish=wish, comment='part3')
+        part3.save()
+        self.assertEqual(75, wish.percentage_of_completion)
+        
+        part4 = WishPart(wish=wish, comment='part4')
+        part4.save()
+        self.assertEqual(100, wish.percentage_of_completion)
\ No newline at end of file