Show testrun results in statistics

app/models/code_ocean/file.rb

@@ -21,6 +21,7 @@ module CodeOcean
     belongs_to :file_type
 
     has_many :files
+    has_many :testruns
     alias_method :descendants, :files
 
     mount_uploader :native_file, FileUploader

app/models/submission.rb

@@ -7,6 +7,8 @@ class Submission < ActiveRecord::Base
 
   belongs_to :exercise
 
+  has_many :testruns
+
   delegate :execution_environment, to: :exercise
 
   scope :final, -> { where(cause: 'submit') }

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

@@ -38,7 +38,7 @@ h1 = "#{@exercise} (external user #{@external_user})"
       table.table
         thead
           tr
-            - ['.time', '.cause', '.score', '.time_difference'].each do |title|
+            - ['.time', '.cause', '.score', '.tests', '.time_difference'].each do |title|
               th.header = t(title)
         tbody
           - deltas = submissions.map.with_index {|item, index| delta = item.created_at - submissions[index - 1].created_at if index > 0; if delta == nil or delta > 30*60 then 0 else delta end}
@@ -47,6 +47,7 @@ h1 = "#{@exercise} (external user #{@external_user})"
               td.clickable = submission.created_at.strftime("%F %T")
               td = submission.cause
               td = submission.score
+              td = submission.testruns.map{|run| run.passed ? 'p' : 'f'}.join(' ')
               td = Time.at(deltas[1..index].inject(:+)).utc.strftime("%H:%M:%S") if index > 0
     p = t('.addendum')