Render teacher_markdown clientside

[Hamms]

So we can render it with our SafeMarkdown component.

Prerequisite to opening this field up for translations.

Because this is switching the renderer from redcarpet to remark, it also requires content updates for many of the affected levels; that work is being tracked here.

Links

• jira
• content updates

Testing story

As with other renderer switches, the testing pattern for this is to:

• Output all affected markdown to a markdown.json file
• Render all markdown with Redcarpet, output to redcarpet.json
• Render all markdown with Remark, output to remark.json
• Use https://github.com/Hamms/html-equivalency to compare redcarpet.json and remark.json and identify the levels for which there is an html change

Reviewer Checklist:

• Tests provide adequate coverage
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked

[davidsbailey]

Code changes look good, but can you please remind me, why is it important to switch to client-side rendering via SafeMarkdown? is the important part to use remark rather than redcarpet, and can we not render remark server-side?

[davidsbailey]

I hate to make style comments now that we have prettier, but can you please preserve the alphabetical order?

[davidsbailey]

nice cleanup!

[Hamms]

The important part is to use a renderer that can detect and remove "unsafe" markup; we currently have a solution for this using remark and hast-util-sanitize and do not have a solution for redcarpet, nor do we have a way to render remark serverside.

[davidsbailey]

The important part is to use a renderer that can detect and remove "unsafe" markup; we currently have a solution for this using remark and hast-util-sanitize and do not have a solution for redcarpet, nor do we have a way to render remark serverside.

Thanks @Hamms . what categories of content need detection/removal of "unsafe" markup?

[Hamms]

Any content that is externally sourced; in this case, sourced from translators.

[Hamms]

All affected levels have been updated (https://docs.google.com/spreadsheets/d/1p-KP5RMQn3d-aNuagCCyGKyUfC7L8893gPoT2e3fCmA/edit#gid=153934544), and I've confirmed that no new inconsistencies were added in the last two weeks, so this is now safe to merge!