Notifications don't update permalinks with name changes

[GeorgeColdham]

Describe the bug
When a notification is received, the link to the article/comment is using the same permalink as can be used to reference it.
If a user changes their name this permalink is broken and leads to a 404 page.

To Reproduce

1. Generate a notification somehow
2. Change the username of the notification sender
3. Try following the link

Expected behavior
The link should still work and lead to the Article or comment.

Screenshots
Notification with url

Following the notification

Comment on article. NOTE: Username change

Permalink url of comment after name change

Desktop (please complete the following information):

• OS: Mac OS Mojave 10.14.5
• Browser: Google Chrome
• Version: 75

Suggestion
My suggestion for a fix, would be to have accounts linked to a uniquely generated id, allowing the names to be changed independently of any permalinks. The username could redirect to the unique id version of the url.

[Zhao-Andy]

Thanks for the bug report! I think I'll most likely work on this. Our current approach is to show static data to prevent excessive queries to the database, and my guess is that the notification data is not up-to-date after the user changes their username.

[citizen428]

@Zhao-Andy Did you ever get around to work on this? If not, do you want me to take over?

[Zhao-Andy]

Ah nope, feel free to go ahead! I believe this is still an issue but not 100% sure

[rhymes]

When notifications are created, we store some information in the notification object, as a JSON payload:

forem/app/services/notifications/new_comment/send.rb

Lines 22 to 25 in c357307

	json_data = {
	user: user_data(comment.user),
	comment: comment_data(comment)
	}

This information contains user_data and comment_data. user_data in particular contains information about the user's name and username, the comment's and article's paths:

forem/app/services/notifications.rb

Lines 6 to 7 in c357307

	name: user.name,
	username: user.username,

forem/app/services/notifications.rb

Line 19 in c357307

path: comment.path,

forem/app/services/notifications.rb

Line 29 in c357307

path: comment.commentable.path,

This information, stored in notification.json_data is then used to display the HTML of the notification in /notifications:

see https://github.com/forem/forem/blob/master/app/views/notifications/_comment.html.erb

I imagine that when a user changes username, all the notifications they are the source of are not updated with the changed username, and as a consequence, the paths of all the articles.

[rhymes]

Hi @cmgorton, I'm reopening this based on #13663 and the PR that was submit for it: #13689

#13663 and its PR only focus on the dashboard list of articles, not the full experience (notifications included)