test: Add tests for /api/user/feed endpoint

1.  Integration of comprehensive functional tests (`TestUserPromoFeed`) that verify core endpoint behaviors:
    - Accurate user-specific promo targeting based on age and country.
    - Correct dynamic calculation of promo 'active' status (considering dates, usage counts, and unique code availability).
    - Effective filtering via `active` (boolean) and `category` (case-insensitive) query parameters.
    - Proper pagination functionality using `limit` and `offset`, including `X-Total-Count` header validation.
    - Verification of response data structure, ensuring exclusion of sensitive promo code values.
    - Correct reflection of promo data updates (e.g., a promo becoming inactive after an edit) in the feed.

2.  Addition of new focused validation tests (`TestUserPromoFeed`) using parameterized inputs to cover edge cases and invalid requests:
    - Authentication checks, specifically ensuring `401 Unauthorized` for requests lacking a token.
    - Rigorous validation of query parameters (`limit`, `offset`, `category`, `active`):
        - Invalid data types and formats (e.g., non-numeric for `limit`/`offset`, non-boolean for `active`).
        - Values outside defined constraints (e.g., negative `limit`/`offset`, category string length violations).
        - Empty string inputs for parameters that require specific formats.
    - Rejection of requests containing unexpected or unsupported query parameters, returning a `400 Bad Request`.

Author: RandomProgramm3r

promo_code/user/serializers.py

@@ -297,6 +297,19 @@ def validate(self, attrs):
 
         return attrs
 
+    def validate_category(self, value):
+        cotegory = self.initial_data.get('category')
+
+        if cotegory is None:
+            return value
+
+        if value == '':
+            raise rest_framework.exceptions.ValidationError(
+                'Invalid category format.',
+            )
+
+        return value
+
     def _validate_int_field(self, field_name, attrs, field_errors):
         value_str = self.initial_data.get(field_name)
         if value_str is None:

promo_code/user/tests/user/base.py

@@ -14,6 +14,11 @@ def setUpTestData(cls):
         cls.user_signup_url = django.urls.reverse('api-user:user-sign-up')
         cls.user_signin_url = django.urls.reverse('api-user:user-sign-in')
         cls.user_profile_url = django.urls.reverse('api-user:user-profile')
+        cls.user_feed_url = django.urls.reverse('api-user:user-feed')
+
+        cls.company_signin_url = django.urls.reverse(
+            'api-business:company-sign-in',
+        )
         cls.promo_list_create_url = django.urls.reverse(
             'api-business:promo-list-create',
         )
@@ -28,16 +33,36 @@ def setUpTestData(cls):
             email=company1_data['email'],
         )
         response1 = cls.client.post(
-            django.urls.reverse(
-                'api-business:company-sign-in',
-            ),
+            cls.company_signin_url,
             {
                 'email': company1_data['email'],
                 'password': company1_data['password'],
             },
             format='json',
         )
         cls.company1_token = response1.data['access']
+        cls.company1_name = cls.company1.name
+
+        company2_data = {
+            'name': 'Synergy Solutions Co.',
+            'email': 'company2@example.com',
+            'password': 'AnotherSecurePass456!',
+        }
+        business.models.Company.objects.create_company(**company2_data)
+
+        cls.company2 = business.models.Company.objects.get(
+            email=company2_data['email'],
+        )
+        response2 = cls.client.post(
+            cls.company_signin_url,
+            {
+                'email': company2_data['email'],
+                'password': company2_data['password'],
+            },
+            format='json',
+        )
+        cls.company2_token = response2.data['access']
+        cls.company2_name = cls.company2.name
 
     def tearDown(self):
         business.models.Company.objects.all().delete()
@@ -54,3 +79,10 @@ def promo_detail_url(cls, promo_id):
             'api-user:user-promo-detail',
             kwargs={'id': promo_id},
         )
+
+    @classmethod
+    def get_promo_business_detail_url(cls, promo_id):
+        return django.urls.reverse(
+            'api-business:promo-detail',
+            kwargs={'id': promo_id},
+        )

promo_code/user/tests/user/operations/test_detail.py

@@ -59,7 +59,12 @@ def setUp(self):
 
         promo_us = {
             'description': 'Gift sleeping mask with car loan application',
-            'target': {'age_from': 28, 'age_until': 50, 'country': 'us'},
+            'target': {
+                'age_from': 28,
+                'age_until': 50,
+                'country': 'us',
+                'categories': ['cars'],
+            },
             'max_count': 1,
             'active_from': '2025-01-01',
             'active_until': '2028-12-30',