Merge pull request #382 from bounswe/backend-follow-endpoint

Add follow/unfollow functionality with tests and Swagger docs

app/backend/v1/apps/accounts/migrations/0002_follow.py

@@ -0,0 +1,27 @@
+# Generated by Django 5.1.4 on 2024-12-14 11:16
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('accounts', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Follow',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('follower', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='following', to=settings.AUTH_USER_MODEL)),
+                ('following', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='followers', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'unique_together': {('follower', 'following')},
+            },
+        ),
+    ]

app/backend/v1/apps/accounts/models.py

@@ -3,3 +3,15 @@
 
 class CustomUser(AbstractUser):
     pass
+
+class Follow(models.Model):
+    follower = models.ForeignKey(CustomUser, on_delete=models.CASCADE, related_name="following")
+    following = models.ForeignKey(CustomUser, on_delete=models.CASCADE, related_name="followers")
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        unique_together = ('follower', 'following')  # Each follower-following pair is unique
+
+    def __str__(self):
+        return f"{self.follower.username} follows {self.following.username}"
+

app/backend/v1/apps/accounts/tests.py

@@ -1,7 +1,9 @@
 from django.urls import reverse
-from rest_framework.test import APITestCase
+from rest_framework.test import APITestCase, APIClient
 from rest_framework import status
-from v1.apps.accounts.models import CustomUser
+from v1.apps.accounts.models import CustomUser, Follow
+from django.test import TestCase
+
 
 class AccountsTests(APITestCase):
     def setUp(self):
@@ -79,3 +81,30 @@ def test_login_nonexistent_user(self):
         response = self.client.post(self.login_url, login_data)
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
         self.assertIn("Invalid credentials", response.data['error'])
+
+class FollowUserTest(TestCase):
+    def setUp(self):
+        self.client = APIClient()
+        self.follower = CustomUser.objects.create_user(username="follower", password="password")
+        self.following = CustomUser.objects.create_user(username="following", password="password")
+        self.url = reverse('toggle-follow', args=[self.following.id])
+
+    def test_follow_user_authenticated(self):
+        self.client.force_authenticate(user=self.follower)
+        response = self.client.post(self.url)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        follow_exists = Follow.objects.filter(follower=self.follower, following=self.following).exists()
+        self.assertTrue(follow_exists)
+
+    def test_unfollow_user_authenticated(self):
+        self.client.force_authenticate(user=self.follower)
+        self.client.post(self.url)  # Follow first
+        response = self.client.post(self.url)  # Then unfollow
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        follow_exists = Follow.objects.filter(follower=self.follower, following=self.following).exists()
+        self.assertFalse(follow_exists)
+
+    def test_follow_user_unauthenticated(self):
+        response = self.client.post(self.url)
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
+

app/backend/v1/apps/accounts/urls.py

@@ -4,4 +4,5 @@
 urlpatterns = [
     path('signup/', views.sign_up, name='sign-up'),
     path('login/', views.login, name='login'),
+    path('<int:user_id>/follow/', views.toggle_follow, name='toggle-follow'),
 ]

app/backend/v1/apps/accounts/views.py

@@ -7,6 +7,9 @@
 from drf_yasg import openapi
 from rest_framework.permissions import AllowAny
 from rest_framework.decorators import permission_classes
+from v1.apps.accounts.models import CustomUser, Follow
+from rest_framework.permissions import IsAuthenticated
+
 User = get_user_model()
 
 # Sign-up view
@@ -90,4 +93,56 @@ def login(request):
             'refresh_token': str(refresh)
         }, status=status.HTTP_200_OK)
     else:
-        return Response({"error": "Invalid credentials"}, status=status.HTTP_400_BAD_REQUEST)
+        return Response({"error": "Invalid credentials"}, status=status.HTTP_400_BAD_REQUEST)
+
+
+@swagger_auto_schema(
+    method='post',
+    operation_description="Toggle follow/unfollow for a specific user. If the user is not followed, the current user will follow them. If the user is already followed, the follow will be removed.",
+    operation_summary="Toggle Follow on a User",
+    responses={
+        201: openapi.Response(
+            description="User followed successfully",
+            examples={
+                'application/json': {
+                    'message': 'User followed successfully'
+                }
+            }
+        ),
+        200: openapi.Response(
+            description="User unfollowed successfully",
+            examples={
+                'application/json': {
+                    'message': 'User unfollowed successfully'
+                }
+            }
+        ),
+        404: openapi.Response(
+            description="User not found",
+            examples={
+                'application/json': {
+                    'error': 'User not found'
+                }
+            }
+        )
+    }
+)
+@api_view(['POST'])
+@permission_classes([IsAuthenticated])
+def toggle_follow(request, user_id):
+    try:
+        following_user = CustomUser.objects.get(id=user_id)
+    except CustomUser.DoesNotExist:
+        return Response({"error": "User not found"}, status=status.HTTP_404_NOT_FOUND)
+
+    follower = request.user
+    if follower == following_user:
+        return Response({"error": "You cannot follow yourself"}, status=status.HTTP_400_BAD_REQUEST)
+
+    follow_instance, created = Follow.objects.get_or_create(follower=follower, following=following_user)
+
+    if not created:
+        follow_instance.delete()
+        return Response({"message": "User unfollowed successfully"}, status=status.HTTP_200_OK)
+
+    return Response({"message": "User followed successfully"}, status=status.HTTP_201_CREATED)