ProFormA export: Uncaught exception for invalid characters

[MrSerth]

Exporting a CodeHarbor task might fail with an uncaught exception if the error contains a Ruby object.

I discovered the bug while testing openHPI/codeocean#2503 (comment). This was caused by using the linked exercise example and adding an empty model solution (without any files). However, this error is independent of the model solution issue since any unescaped sequence starting with # seems to cause errors.

#<JSON::ParserError: unexpected character: '#<Nokogiri::XML::SyntaxError: 13'>

codeharbor/app/controllers/tasks_controller.rb

Line 94 in bde3960

redirect_to :root, danger: JSON.parse(e.message).map {|msg| t("proforma_errors.#{msg}", default: msg) }.join('<br>')