Ensure output is shown even if no test command is given

app/assets/javascripts/editor/evaluation.js

@@ -150,6 +150,7 @@ CodeOceanEditorEvaluation = {
     }
 
     var element = this.findOrCreateOutputElement(index);
+    // Switch all four lines below to enable the output of images and render <IMG/> tags
     if (!colorize) {
       if (output.stdout !== undefined && output.stdout !== '') {
         //element.append(output.stdout)

app/controllers/submissions_controller.rb

@@ -235,7 +235,11 @@ class SubmissionsController < ApplicationController
       # Filter out information about run_command, test_command, user or working directory
       run_command = @submission.execution_environment.run_command % command_substitutions(sanitize_filename)
       test_command = @submission.execution_environment.test_command % command_substitutions(sanitize_filename)
-      unless /root|workspace|#{run_command}|#{test_command}/.match(message)
+      if test_command.blank?
+        # If no test command is set, use the run_command for the RegEx below. Otherwise, no output will be displayed!
+        test_command = run_command
+      end
+      unless /root|workspace|#{run_command.gsub('.', '\.')}|#{test_command}/.match(message)
         parse_message(message, 'stdout', tubesock)
       end
     end