This is a preparatory commit for using isort for sorting all of our
imports, merging changes to files where we can easily review the
changes as something we're happy with.
These are also files with relatively little active development, which
means we don't expect much merge conflict risk from these changes.
In commit de65a04 we can see that if the need ever arises to modify
how stream descriptions are rendered, we would need to make changes
at 5 different call points which can be quite cumbersome. So this
functionality has been extracted to a new method called
'render_stream_descriptions'.
We want to use the baseline features of bugdown, but not fancy things
like inline URL previews, since the whole structure of stream
descriptions is to have a single-line thing supporting some
formatting.
The migration part of this change fixes a bug encountered by some
organizations upgrading from older versions of Zulip.
This commit does the following three things:
1. Update stream model to accomodate rendered description.
2. Render and save the stream rendered description on update.
3. Render and save stream descriptions on creation.
Further, the stream's rendered description is also sent whenever the
stream's description is being sent.
This is preparatory work for eliminating the use of the
non-authoritative marked.js markdown parser for stream descriptions.
Tim Abbott
Hemanth V. Alluri
Anders Kaseorg