enhance: render line-wrapped code files instead

Run fold on provided files and compare the output with diff. If the file
doesn't contain any lines that are over the configured threshold, it
will be identical to the original. In this case we replace the temp file
with a symlink for easy identification in the template.

app/helpers/file_helper.rb

@@ -1,3 +1,4 @@
+require 'English'
 require 'zip'
 require 'tmpdir'
 require 'open3'
@@ -535,9 +536,20 @@ def line_wrap(path, width: 200)
     basename = File.basename(path)
     output = File.join(dir, "WRAPPED-#{basename}")
     begin
-      fold_cmd = "fold --width #{width} #{path.shellescape} > #{output}"
       logger.debug "Running fold on #{path} to limit line width to #{width}"
-      system_try_within 5, "Failed running fold on #{path} to limit line width to #{width}", fold_cmd
+      system("fold --width #{width} #{path.shellescape} > #{output}", exception: true)
+      # compare input and output files, replace the output with a symlink if they are identical
+      system "diff #{path.shellescape} #{output}"
+      case $CHILD_STATUS.exitstatus
+      when 0
+        logger.debug "File #{path} does not contain lines longer than #{width}"
+        File.unlink(output)
+        File.symlink(path, output)
+      when 1
+        logger.debug "File #{path} contains lines longer than #{width}, line wrapping will be applied"
+      else
+        raise "Error comparing original and line-wrapped files!"
+      end
     rescue => e
       logger.error "Failed to run fold on #{path} to limit line width to #{width}. Rescued with error:\n\t#{e.message}"
     end

app/views/task/task_pdf.pdf.erb

@@ -112,8 +112,15 @@ No Tutor % Supervisor's Name
   <%
     if file[:type] == 'code'
       if (File.extname(file[:path])[1..-1]) != 'ipynb'
+      # for code files (except Jupyter Notebook), always use files with a WRAPPED- prefix in the filename
+      # Jupyter Notebooks are not processed with line wraps
+      dir = File.dirname(file[:path])
+      name = File.basename(file[:path])
+      pygments_lang = Task.pygments_lang(File.extname(file[:path])[1..-1])
+      wrapped_file = File.join(dir, "WRAPPED-" + name)
+      # [TODO] add notice about line-wrapped files, files that aren't line-wrapped will be a symlink
   %>
-\inputminted[breaklines,linenos,breakanywhere,tabsize=4]{<%= Task.pygments_lang(File.extname(file[:path])[1..-1]) %>}{<%= file[:path] %>}
+\inputminted[breaklines,linenos,breakanywhere,tabsize=4]{<%= pygments_lang %>}{<%= wrapped_file %>}
   <%  else %>
 \jupynotex{<%= file[:path] %>}
   <%