Rails mailer previews should be available in production

[ragesoss]

Current Behavior:

Wiki Education Dashboard sends out a variety of emails in various circumstances. However, these previews are not available in production — only in staging and development environments. Also, the staging environment — https://dashboard-testing.wikiedu.org/rails/mailers — is not necessarily up-to-date, not all the previews work (because some previews expect example records to be available in the database), and some could reveal private information if enabled on production (because, for example, they use the most recent record of a given type that's in the database).

Desired Behavior:

Mailer previews should be available in production, and should work either without relying on live records from the database or should ensure that only public information is used to generate the previews.

Previews checked for privacy and database independence

• [x] Active Course Mailer
• [ ] Alert Mailer
• [ ] Course Advice Mailer
• [x] Course Approval Followup Mailer
• [x] Course Approval Mailer
• [ ] Course Submission Mailer
• [ ] Did You Know Alert Mailer
• [x] Fall2017 Cmu Experiment Mailer
• [ ] First Enrolled Student Alert Mailer
• [ ] High Quality Article Assignment Mailer
• [x] New Instructor Enrollment Mailer
• [ ] No Enrolled Students Alert Mailer
• [ ] Overdue Training Alert Mailer
• [ ] Survey Mailer
• [ ] Suspected Plagiarism Mailer
• [ ] Term Recap Mailer
• [ ] Ticket Notification Mailer
• [x] Unsubmitted Course Alert Mailer
• [ ] Untrained Students Alert Mailer
• [x] Wiki Email Mailer

[ragesoss]

See the Course Approval Mailer preview for examples of how to work around mailers that expect records to behave like production records in the database; define_singleton_method can work around these cases to avoid using any production records in the previews.

[cyrillefr]

Hello @ragesoss, may I work on this one ?

Btw, the Unsubmitted Course Alert Mailer does not work(but I fixed it so the check may stay :) ).

[ragesoss]

@cyrillefr sure! I know I worked on some of these last year, and there might be some that are already okay and just need to be double-checked.