Prior to this commit we were loading a large number of thread messages without any pagination. This commit attempts to fix this and also improves the following points:
- code sharing between channels and threads:
Attempts to reuse/share the code use in channels for threads. To make it possible part of this code has been extracted in dedicated helpers or has been improved to reduce the duplication needed.
Examples of extracted helpers:
- `stackingContextFix`: the ios hack for rendering bug when momentum scrolling is interrupted
- `scrollListToMessage`, `scrollListToTop`, `scrollListToBottom`: a series of helper to correctly scroll to a specific position in the list of messages
- better general performance of listing messages:
One of the main changes which has been made is to remove the computation of visible message during scroll, it will only happen when needed (update last read for example). This constant recomputation of `message.visible` on intersection observer event while scrolling was consuming a lot of CPU time.
Someone who cannot chat is also not able to join chat channels,
so we may not check all the time user.can_chat? && user.can_join_chat_channel?
and just call user.can_join_chat_channel? instead.
Prior to this change `registered_bookmarkable` would return `nil` as `type` in `Bookmark.registered_bookmarkable_from_type(type)` would be `ChatMessage` and we registered a `Chat::Message` class.
This commit will now properly rely on each model `polymorphic_class_for(name)` to help us infer the proper type from a a `bookmarkable_type`.
Tests have also been added to ensure that creating/destroying chat message bookmarks is working correctly.
---
Longer explanation
Currently when you save a bookmark in the database, it's associated to another object through a polymorphic relationship, which will is represented by two columns: `bookmarkable_id` and `bookmarkable_type`. The `bookmarkable_id` contains the id of the relationship (a post ID for example) and the `bookmarkable_type` contains the type of the object as a string by default, (`"Post"` for example).
Chat plugin just started namespacing objects, as a result a model named `ChatMessage` is now named `Chat::Message`, to avoid complex and risky migrations we rely on methods provided by rails to alter the `bookmarkable_type` when we save it: we want to still save it as `"ChatMessage"` and not `"Chat::Message"`. And, to retrieve the correct model when we load the bookmark from the database: we want `"ChatMessage"` to load the `Chat::Message` model and not the `ChatMessage`model which doesn't exist anymore.
On top of this the bookmark codepath is allowing plugins to register types and will check against these types, so we alter this code path to be able to do a similar ChatMessage <-> Chat::Message dance and allow to check the type is valid. In the specific case of this commit, we were retrieving a `"ChatMessage"` bookmarkable_type from the DB and looking for it in the registered bookmarkable types which contain `Chat::Message` and not `ChatMessage`.
This commit main goal was to comply with Zeitwerk and properly rely on autoloading. To achieve this, most resources have been namespaced under the `Chat` module.
- Given all models are now namespaced with `Chat::` and would change the stored types in DB when using polymorphism or STI (single table inheritance), this commit uses various Rails methods to ensure proper class is loaded and the stored name in DB is unchanged, eg: `Chat::Message` model will be stored as `"ChatMessage"`, and `"ChatMessage"` will correctly load `Chat::Message` model.
- Jobs are now using constants only, eg: `Jobs::Chat::Foo` and should only be enqueued this way
Notes:
- This commit also used this opportunity to limit the number of registered css files in plugin.rb
- `discourse_dev` support has been removed within this commit and will be reintroduced later
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* FIX: Channel archive N1 when serializing current user
The `ChatChannelSerializer` serializes the archive for the
channel if it is present, however this was causing an N1 for
the current user serializer in the case of DM channels, which
were not doing `includes(:chat_channel_archive)` in the
`ChatChannelFetcher`.
DM channels cannot be archived, so we can just never try to serialize
the archive for DM channels in `ChatChannelSerializer`, which
removes the N1.
* DEV: Add N1 performance spec for latest.html preloading
We modify current user serializer in chat, so it's a good
idea to have some N1 performance specs to avoid regressions
here.
Note this is a very large PR, and some of it could have been splited, but keeping it one chunk made it to merge conflicts and to revert if necessary. Actual new code logic is also not that much, as most of the changes are removing js tests, adding system specs or moving things around.
To make it possible this commit is doing the following changes:
- converting (and adding new) existing js acceptances tests into system tests. This change was necessary to ensure as little regressions as possible while changing paradigm
- moving away from store. Using glimmer and tracked properties requires to have class objects everywhere and as a result works well with models. However store/adapters are suffering from many bugs and limitations. As a workaround the `chat-api` and `chat-channels-manager` are an answer to this problem by encapsulating backend calls and frontend storage logic; while still using js models.
- dropping `appEvents` as much as possible. Using tracked properties and a better local storage of channel models, allows to be much more reactive and doesn’t require arbitrary manual updates everywhere in the app.
- while working on replacing store, the existing work of a chat api (backend) has been continued to support more cases.
- removing code from the `chat` service to separate concerns, `chat-subscriptions-manager` and `chat-channels-manager`, being the largest examples of where the code has been rewritten/moved.
Future wok:
- improve behavior when closing/deleting a channel, it's already slightly buggy on live, it's rare enough that it's not a big issue, but should be improved
- improve page objects used in chat
- move more endpoints to the API
- finish temporarily skipped tests
- extract more code from the `chat` service
- use glimmer for `chat-messages`
- separate concerns in `chat-live-pane`
- eventually add js tests for `chat-api`, `chat-channels-manager` and `chat-subscriptions-manager`, they are indirectly heavy tested through system tests but it would be nice to at least test the public API
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Joffrey JAFFEUX
Andrei Prigorshnev
Martin Brennan
David Taylor