Adding a mixin to a class in a plugin?

Development
5

I do it in Topic List Previews: https://github.com/paviliondev/discourse-topic-previews/blob/master/assets/javascripts/discourse/initializers/preview-edits.js.es6

Specific example: api.modifyClass('component:topic-list', Settings);

I did this to break out shared code that would otherwise have been repeated and almost a cut and paste.