Refactor test utilities and enhance ASGI settings

- Cleaned up and standardized assertions in ApiTestMixin for API response validation.
- Updated ASGI settings to use os.environ for setting the DJANGO_SETTINGS_MODULE.
- Removed unused imports and improved formatting in settings.py.
- Refactored URL patterns in urls.py for better readability and organization.
- Enhanced view functions in views.py for consistency and clarity.
- Added .flake8 configuration for linting and style enforcement.
- Introduced type stubs for django-environ to improve type checking with Pylance.

email_service/backends.py

@@ -1,13 +1,13 @@
 from django.core.mail.backends.base import BaseEmailBackend
-from django.contrib.sites.shortcuts import get_current_site
 from django.core.mail.message import sanitize_address
 from .services import EmailService
 from .models import EmailConfiguration
 
+
 class ForwardEmailBackend(BaseEmailBackend):
     def __init__(self, fail_silently=False, **kwargs):
         super().__init__(fail_silently=fail_silently)
-        self.site = kwargs.get('site', None)
+        self.site = kwargs.get("site", None)
 
     def send_messages(self, email_messages):
         """
@@ -23,7 +23,7 @@ class ForwardEmailBackend(BaseEmailBackend):
                 sent = self._send(message)
                 if sent:
                     num_sent += 1
-            except Exception as e:
+            except Exception:
                 if not self.fail_silently:
                     raise
         return num_sent
@@ -33,11 +33,14 @@ class ForwardEmailBackend(BaseEmailBackend):
         if not email_message.recipients():
             return False
 
-        # Get the first recipient (ForwardEmail API sends to one recipient at a time)
+        # Get the first recipient (ForwardEmail API sends to one recipient at a
+        # time)
         to_email = email_message.to[0]
 
         # Get site from connection or instance
-        if hasattr(email_message, 'connection') and hasattr(email_message.connection, 'site'):
+        if hasattr(email_message, "connection") and hasattr(
+            email_message.connection, "site"
+        ):
             site = email_message.connection.site
         else:
             site = self.site
@@ -49,11 +52,16 @@ class ForwardEmailBackend(BaseEmailBackend):
         try:
             config = EmailConfiguration.objects.get(site=site)
         except EmailConfiguration.DoesNotExist:
-            raise ValueError(f"Email configuration not found for site: {site.domain}")
+            raise ValueError(
+                f"Email configuration not found for site: {
+                    site.domain}"
+            )
 
         # Get the from email, falling back to site's default if not provided
         if email_message.from_email:
-            from_email = sanitize_address(email_message.from_email, email_message.encoding)
+            from_email = sanitize_address(
+                email_message.from_email, email_message.encoding
+            )
         else:
             from_email = config.default_from_email
 
@@ -62,13 +70,16 @@ class ForwardEmailBackend(BaseEmailBackend):
 
         # Get reply-to from message headers or use default
         reply_to = None
-        if hasattr(email_message, 'reply_to') and email_message.reply_to:
+        if hasattr(email_message, "reply_to") and email_message.reply_to:
             reply_to = email_message.reply_to[0]
-        elif hasattr(email_message, 'extra_headers') and 'Reply-To' in email_message.extra_headers:
-            reply_to = email_message.extra_headers['Reply-To']
+        elif (
+            hasattr(email_message, "extra_headers")
+            and "Reply-To" in email_message.extra_headers
+        ):
+            reply_to = email_message.extra_headers["Reply-To"]
 
         # Get message content
-        if email_message.content_subtype == 'html':
+        if email_message.content_subtype == "html":
             # If it's HTML content, we'll send it as text for now
             # You could extend this to support HTML emails if needed
             text = email_message.body
@@ -82,10 +93,10 @@ class ForwardEmailBackend(BaseEmailBackend):
                 text=text,
                 from_email=from_email,
                 reply_to=reply_to,
-                site=site
+                site=site,
             )
             return True
-        except Exception as e:
+        except Exception:
             if not self.fail_silently:
                 raise
             return False