Reduce SQL queries for external user statistics

Fixes CODEOCEAN-100
Fixes CODEOCEAN-YN
Fixes CODEOCEAN-10H

app/controllers/exercises_controller.rb

@@ -521,7 +521,8 @@ class ExercisesController < ApplicationController
       submissions = Submission.where(contributor: @external_user, exercise: @exercise)
         .in_study_group_of(current_user)
         .order(:created_at)
-      @show_autosaves = params[:show_autosaves] == 'true' || submissions.none? {|s| s.cause != 'autosave' }
+        .includes(:exercise, testruns: [:testrun_messages, {file: [:file_type]}], files: [:file_type])
+      @show_autosaves = params[:show_autosaves] == 'true' || submissions.where.not(cause: 'autosave').none?
       submissions = submissions.where.not(cause: 'autosave') unless @show_autosaves
       interventions = UserExerciseIntervention.where('user_id = ?  AND exercise_id = ?', @external_user.id,
         @exercise.id)

app/models/testrun.rb

@@ -7,6 +7,8 @@ class Testrun < ApplicationRecord
   belongs_to :testrun_execution_environment, optional: true, dependent: :destroy
   has_many :testrun_messages, dependent: :destroy
 
+  CONSOLE_OUTPUT = %i[stdout stderr].freeze
+
   enum status: {
     ok: 0,
     failed: 1,
@@ -21,6 +23,10 @@ class Testrun < ApplicationRecord
   validates :status, presence: true
 
   def log
-    testrun_messages.output.pluck(:log).join.presence
+    if testrun_messages.loaded?
+      testrun_messages.filter {|m| m.cmd_write? && CONSOLE_OUTPUT.include?(m.stream) }.pluck(:log).join.presence
+    else
+      testrun_messages.output.pluck(:log).join.presence
+    end
   end
 end

app/views/exercises/external_users/statistics.html.slim

@@ -76,7 +76,7 @@ h1
                 td = this.cause
                 td = this.score
                 td.align-middle
-                  -this.testruns.includes(:file).order("files.name").each do |run|
+                  -this.testruns.sort_by {|t| [t.file&.name ? 0 : 1, t.file&.name]}.each do |run|
                     - if run.passed
                       .unit-test-result.positive-result title=[run.file&.filepath, run.log].join.strip
                     - else