89 - ManyToManyField and Reverse Relations

tweets/migrations/0006_auto_20200108_2040.py

@@ -0,0 +1,20 @@
+# Generated by Django 2.2 on 2020-01-08 20:40
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('tweets', '0005_tweet_parent'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='tweet',
+            name='user',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='tweets', to=settings.AUTH_USER_MODEL),
+        ),
+    ]

tweets/models.py

@@ -13,7 +13,7 @@ class Tweet(models.Model):
     # Maps to SQL data
     # id = models.AutoField(primary_key=True)
     parent = models.ForeignKey("self", null=True, on_delete=models.SET_NULL)
-    user = models.ForeignKey(User, on_delete=models.CASCADE) # many users can many tweets
+    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="tweets") # many users can many tweets
     likes = models.ManyToManyField(User, related_name='tweet_user', blank=True, through=TweetLike)
     content = models.TextField(blank=True, null=True)
     image = models.FileField(upload_to='images/', blank=True, null=True)

tweets/tests.py

@@ -42,13 +42,22 @@ def test_tweet_list(self):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(len(response.json()), 3)
 
+    def test_tweets_related_name(self):
+        user = self.user
+        self.assertEqual(user.tweets.count(), 2)
+
     def test_action_like(self):
         client = self.get_client()
         response = client.post("/api/tweets/action/", 
             {"id": 1, "action": "like"})
-        self.assertEqual(response.status_code, 200)
         like_count = response.json().get("likes")
+        user = self.user
+        my_like_instances_count = user.tweetlike_set.count()
+        my_related_likes = user.tweet_user.count()
+        self.assertEqual(response.status_code, 200)
         self.assertEqual(like_count, 1)
+        self.assertEqual(my_like_instances_count, 1)
+        self.assertEqual(my_like_instances_count, my_related_likes)
 
     def test_action_unlike(self):
         client = self.get_client()