fix: handle empty notification recipients

[SahilJat]

Thanks for submitting a PR! Please check the boxex below:

• I have read the Contributing
  Guide.

• I have added information to docs/ if required
  so people know about the feature.

• I have filled in the "Changes" section below.

• I have filled in the "How did you test this
  code" section below.

  Changes

  Closes Sendgrid API calls raising HTTP 400 Bad Requests #7353
  This PR resolves an issue where the background tasks for sending API usage and flag blocked notifications crash with a BadRequestsError: HTTP Error 400: Bad Request.

  This occurs when using external API-based email
  backends (like SendGrid or AWS SES) and the
  organisation has no valid recipients (e.g., zero
  total users, or no admin users when the usage
  threshold is <100%). Unlike traditional SMTP
  backends, API backends strictly validate the payload and return a 400 error if the recipient_list is empty.
  Changes made:

• Added an early return guard checking if not recipient_emails: in _send_api_usage_notification.

• Added the same early return guard in
  send_api_flags_blocked_notification to prevent the same crash there.

• Logs a warning (notification.no_recipients)
  instead of attempting to send the email.

How did you test this code?

• Added a new unit test: test_handle_api_usage_notifications__no_admin_users_ _skips_notification to explicitly verify that the
  notification is safely skipped and no 400 error is thrown when an organisation has no users.
• Ran existing unit tests for organisations_tasks
  to ensure no regressions.

[vercel]

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[gemini-code-assist]

Code Review

This pull request introduces checks to handle cases where no recipient emails are found for API usage and blocked notifications, including a new unit test for this scenario. Feedback suggests that returning early without creating a notification record will lead to redundant processing and log noise in subsequent task runs, as the organization will be re-evaluated every 12 hours.

[gemini-code-assist]

Returning early here without creating an OrganisationAPIUsageNotification record will cause this organization to be re-processed and a warning to be logged every time the handle_api_usage_notifications task runs (currently every 12 hours). This leads to persistent redundant processing and log noise for organizations with no valid recipients.

Consider creating the notification record even if no emails are sent, to ensure the 'notify once per threshold' logic is respected for the current billing period. While this might mean a newly added admin misses a notification for a threshold already crossed, they would still see the status in the dashboard and receive future notifications.

[Zaimwa9]

Sorry for the back and forth, I thought this has been addressed. It's actually a comment on-point as otherwise the organisations will be re-evaluated on every task run.

Can we move the early return to after the OrganisationAPIUsageNotification.objects.create call please?

[Zaimwa9]

@SahilJat thanks for your contribution. You'll need to run make lint or generate-docs to regenerate the events catalogue as you created 2 new ones

[SahilJat]

Hi @Zaimwa9 i did run make lint and it shows around 22k lines edited , is this fine?

[Zaimwa9]

Sorry, I should have been more specific as the command should be run from api/, it edited all the docs it seems

[SahilJat]

hi @Zaimwa9 thanks for the hint , i did the changes required now, please have a look and let me know.

[Zaimwa9]

Tests need an update 👍

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.35%. Comparing base (2e16ede) to head (5a1373e).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7589      +/-   ##
==========================================
- Coverage   98.50%   98.35%   -0.16%     
==========================================
  Files        1430     1436       +6     
  Lines       54254    54274      +20     
==========================================
- Hits        53444    53382      -62     
- Misses        810      892      +82     

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[SahilJat]

Hi @Zaimwa9 all the test cases are passing and test coverage is covered too. Thanks

[Zaimwa9]

Sorry for the back and forth. Gemini comment is worth addressing