feat: add bff handler context (#577)

enterprise_access/apps/bffs/apps.py

@@ -0,0 +1,8 @@
+""" App config for BFFs """
+
+from django.apps import AppConfig
+
+
+class BffsConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'enterprise_access.apps.bffs'

enterprise_access/apps/bffs/context.py

@@ -0,0 +1,59 @@
+"""
+HandlerContext for bffs app.
+"""
+from enterprise_access.apps.bffs import serializers
+
+
+class HandlerContext:
+    """
+    A context object for managing the state throughout the lifecycle of a Backend-for-Frontend (BFF) request.
+    The `HandlerContext` class stores request information, loaded data, and any errors and warnings
+    that may occur during the request.
+    Attributes:
+        request: The original request object containing information about the incoming HTTP request.
+        user: The original request user information about hte incoming HTTP request.
+        data: A dictionary to store data loaded and processed by the handlers.
+        errors: A list to store errors that occur during request processing.
+        warnings: A list to store warnings that occur during the request processing.
+        enterprise_customer_uuid: The enterprise customer the user is associated with.
+        lms_user_id: The id associated with the authenticated user.
+    """
+
+    def __init__(self, request):
+        """
+        Initializes the HandlerContext with request information, route, and optional initial data.
+        Args:
+            request: The incoming HTTP request.
+        """
+        self._request = request
+        self.data = {}  # Stores processed data for the response
+        self.errors = []  # Stores any errors that occur during processing
+        self.warnings = []  # Stores any warnings that occur during processing
+        self.enterprise_customer_uuid = None
+        self.lms_user_id = None
+
+    @property
+    def request(self):
+        return self._request
+
+    @property
+    def user(self):
+        return self._request.user
+
+    def add_error(self, **kwargs):
+        """
+        Adds an error to the context.
+        Output fields determined by the ErrorSerializer
+        """
+        serializer = serializers.ErrorSerializer(data=kwargs)
+        serializer.is_valid(raise_exception=True)
+        self.errors.append(serializer.data)
+
+    def add_warning(self, **kwargs):
+        """
+        Adds a warning to the context.
+        Output fields determined by the WarningSerializer
+        """
+        serializer = serializers.WarningSerializer(data=kwargs)
+        serializer.is_valid(raise_exception=True)
+        self.warnings.append(serializer.data)

enterprise_access/apps/bffs/serializers.py

@@ -0,0 +1,30 @@
+"""
+Serializers for bffs.
+"""
+from rest_framework import serializers
+
+
+class BaseBFFMessageSerializer(serializers.Serializer):
+    """
+    Base Serializer for BFF messages.
+
+    Fields:
+        user_message (str): A user-friendly message.
+        developer_message (str): A more detailed message for debugging purposes.
+    """
+    developer_message = serializers.CharField()
+    user_message = serializers.CharField()
+
+    def create(self, validated_data):
+        return validated_data
+
+    def update(self, instance, validated_data):
+        return validated_data
+
+
+class ErrorSerializer(BaseBFFMessageSerializer):
+    pass
+
+
+class WarningSerializer(BaseBFFMessageSerializer):
+    pass

enterprise_access/apps/bffs/tests/test_context.py

@@ -0,0 +1,86 @@
+"""
+Text for the BFF context
+"""
+from django.test import RequestFactory, TestCase
+from rest_framework.exceptions import ValidationError
+
+from enterprise_access.apps.api_client.tests.test_constants import DATE_FORMAT_ISO_8601
+from enterprise_access.apps.bffs.context import HandlerContext
+from enterprise_access.apps.core.tests.factories import UserFactory
+from enterprise_access.utils import _curr_date
+
+
+class TestHandlerContext(TestCase):
+    def setUp(self):
+        super().setUp()
+        self.factory = RequestFactory()
+        self.mock_user = UserFactory()
+
+    def test_handler_context_init(self):
+        request = self.factory.get('sample/api/call')
+        request.user = self.mock_user
+        context = HandlerContext(request)
+
+        self.assertEqual(context.request, request)
+        self.assertEqual(context.user, self.mock_user)
+        self.assertEqual(context.data, {})
+        self.assertEqual(context.errors, [])
+        self.assertEqual(context.warnings, [])
+        self.assertEqual(context.enterprise_customer_uuid, None)
+        self.assertEqual(context.lms_user_id, None)
+
+    def test_handler_context_add_error_serializer(self):
+        request = self.factory.get('sample/api/call')
+        request.user = self.mock_user
+        context = HandlerContext(request)
+        expected_output = {
+            "developer_message": "No enterprise uuid associated to the user mock-uuid",
+            "user_message": "You may not be associated with the enterprise.",
+        }
+        # Define kwargs for add_error
+        arguments = {
+            **expected_output,
+            "status": 403  # Add an attribute that is not explicitly defined in the serializer to verify
+        }
+        context.add_error(
+            **arguments
+        )
+        self.assertEqual(expected_output, context.errors[0])
+
+    def test_handler_context_add_error_serializer_is_valid(self):
+        request = self.factory.get('sample/api/call')
+        request.user = self.mock_user
+        context = HandlerContext(request)
+        malformed_output = {
+            "developer_message": "No enterprise uuid associated to the user mock-uuid",
+        }
+        with self.assertRaises(ValidationError):
+            context.add_error(**malformed_output)
+
+    def test_handler_context_add_warning_serializer(self):
+        request = self.factory.get('sample/api/call')
+        request.user = self.mock_user
+        context = HandlerContext(request)
+        expected_output = {
+            "developer_message": "Heuristic Expiration",
+            "user_message": "The data received might be out-dated",
+        }
+        # Define kwargs for add_warning
+        arguments = {
+            **expected_output,
+            "status": 113  # Add an attribute that is not explicitly defined in the serializer to verify
+        }
+        context.add_warning(
+            **arguments
+        )
+        self.assertEqual(expected_output, context.warnings[0])
+
+    def test_handler_context_add_warning_serializer_is_valid(self):
+        request = self.factory.get('sample/api/call')
+        request.user = self.mock_user
+        context = HandlerContext(request)
+        malformed_output = {
+            "user_message": "The data received might be out-dated",
+        }
+        with self.assertRaises(ValidationError):
+            context.add_error(**malformed_output)

enterprise_access/settings/base.py

@@ -74,6 +74,7 @@ def root(*path_fragments):
     'enterprise_access.apps.subsidy_access_policy',
     'enterprise_access.apps.content_assignments',
     'enterprise_access.apps.enterprise_groups',
+    'enterprise_access.apps.bffs',
 )
 
 INSTALLED_APPS += THIRD_PARTY_APPS