The summary and description need to be separated by a blank line.

I don't know that we've standardized this yet for TypeScript, but we should probably have required fields before optional fields. This better matches the requirements imposed in Python for dataclasses, and how we often document things.

While here, can you turn this (and others) into a dedent, so we can save on the join?

Worth mentioning, we'll do a $() for every one of these when constructing the object (since these are instance attributes, not class attributes -- silly ES6 classes).
This is fine if we want that as the default, but since these are set in render, it might be a better failure to leave these as undefined, at least in some cases?

Let's organize _ before #, since _ is semi-public and # is semi-private.
We haven't done this elsewhere, but we should probably also mark the _ ones with the private keyword, unless we need them in tests.

onInitialRender() shouldn't return anything.
If it did, we'd actually want to use this instead of the class name as the type.

Missing a trailing comma.

Missing a trailing comma.

ESLint will complain about the ordering here. This should be in alphabetical order.

Let's define the types for these here.

Since we're touching this, can we change var to const, add a trailing comma on canEdit, and sort the object keys here?

These default values can all be specified in the instance definitions.

If you pull, you can now add:

import { suite } from '@beanbag/jasmine-suites';

Parens around val aren't necessary here.

Ship It!

Change looks ready to go. Just one thing I want to make sure we have an answer for.

Just realized, since we renamed FileAttachmentThumbnail to FileAttachmentThumbnailView, we should at least document the name in a Version Changed, and if there's any reason extensions ever needed to refer to this by name (I don't think so but maybe?) then we'd want an alias from the old name to new name.

There's a section header for this:

/**
 * ...
 *
 * Deprecated:
 *     6.0
 */


When we finally have generated docs for this, that'll show up with a deprecation notice.