Add 'expires' field and '_post_save_set_expiry_date' function

The 'expires' field will enable one to increment / decrement the expiry
date of an ODKToken easily. Included the '_post_save_set_expiry_date'
function to set the 'expires' field value post_save in order to have
access to the 'created' field value

- Update 'test_fails_authentication_past_odk_token_expiry' test

onadata/apps/api/migrations/0007_odktoken_expires.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.10 on 2020-07-17 11:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0006_auto_20191025_0730'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='odktoken',
+            name='expires',
+            field=models.DateTimeField(blank=True, null=True),
+        ),
+    ]

onadata/apps/api/models/odk_token.py

@@ -40,6 +40,7 @@ class ODKToken(models.Model):
         default=ACTIVE,
         max_length=1)
     created = models.DateTimeField(auto_now_add=True)
+    expires = models.DateTimeField(blank=True, null=True)
 
     class Meta:
         app_label = 'api'
@@ -59,6 +60,7 @@ def check_key(self, key):
     def save(self, *args, **kwargs):  # pylint: disable=arguments-differ
         if not self.key:
             self.key = self.generate_key()
+
         return super(ODKToken, self).save(*args, **kwargs)
 
     def generate_key(self):
@@ -69,13 +71,6 @@ def generate_key(self):
     def __str__(self):
         return self.key
 
-    @property
-    def expires(self):
-        """
-        This property holds the datetime of when the Token expires
-        """
-        return self.created + timedelta(days=ODK_TOKEN_LIFETIME)
-
     @property
     def raw_key(self):
         """
@@ -99,5 +94,16 @@ def _post_save_persist_partial_digests(sender, instance=None, **kwargs):
         _persist_partial_digests(instance.user)
 
 
+def _post_save_set_expiry_date(sender, instance=None, **kwargs):
+    if instance and not instance.expires:
+        instance.expires = instance.created + timedelta(
+            days=ODK_TOKEN_LIFETIME)
+        instance.expires = instance.expires.astimezone(
+            instance.created.tzinfo)
+        instance.save()
+
+
 post_save.connect(
     _post_save_persist_partial_digests, sender=ODKToken)
+
+post_save.connect(_post_save_set_expiry_date, sender=ODKToken)

onadata/apps/api/tests/models/test_odk_token.py

@@ -1,7 +1,9 @@
 """
 Test ODK Token module
 """
-from onadata.apps.api.models.odk_token import ODKToken
+from datetime import timedelta
+
+from onadata.apps.api.models.odk_token import ODKToken, ODK_TOKEN_LIFETIME
 from onadata.apps.api.tests.models.test_abstract_models import \
     TestAbstractModels
 
@@ -14,6 +16,9 @@ def test_create_odk_token(self):
         self._create_user_and_login()
         initial_count = ODKToken.objects.count()
 
-        ODKToken.objects.create(user=self.user)
+        token = ODKToken.objects.create(user=self.user)
 
         self.assertEqual(initial_count + 1, ODKToken.objects.count())
+        self.assertEqual(
+            token.expires,
+            token.created + timedelta(days=ODK_TOKEN_LIFETIME))

onadata/apps/logger/tests/test_digest_authentication.py

@@ -128,7 +128,8 @@ def test_fails_authentication_past_odk_token_expiry(self):
         self.user.save()
         odk_token = ODKToken.objects.create(user=self.user)
 
-        odk_token.created = timezone.now() - timedelta(days=400)
+        # Set expiry date of the token to the past
+        odk_token.expires = timezone.now() - timedelta(days=400)
         odk_token.save()
 
         # The value odk_token.key is hashed we need to have the raw_key