detect possible overwriting output files by BoutiquesOutputFilenameRe…

BrainPortal/lib/boutiques_output_filename_renamer.rb

@@ -209,6 +209,53 @@ def after_form
     message
   end
 
+
+
+  # checking that output patterns actually provided in the case of batch tasks
+  # because this module disables CBRAIN standards output suffixes that aim at aprevenitn
+  # from overwriting the output files
+  def final_task_list
+    tasklist = super
+    if tasklist.length > 1 && tasklist.last.is_a?(CbrainTask)
+      descriptor = descriptor_for_final_task_list
+      config_map = descriptor.custom_module_info('BoutiquesOutputFilenameRenamer') || {}
+
+      # check that the output file names are unique at least for same output id
+      # (still there could be overwriting for different output ids)
+
+      config_map.each do |_, pair|
+        fileinputid, outnameinputid = *pair
+        original_outname_pattern    = invoke_params[outnameinputid]
+        next if original_outname_pattern.include?('{task_id}') # usually enough for unique output names for input
+        outname_pattern          = original_outname_pattern.gsub('{time}', '12:23:45') # time is not very reliable
+        outnames                 = {}
+        outname = input_userfile = nil
+        t, _    = tasklist.each_with_index.detect do |t, i|
+          input_userfile_id = t.invoke_params[fileinputid]
+          input_userfile    = Userfile.find(input_userfile_id)
+          outname           = t.output_name_from_pattern(outname_pattern, input_userfile.name) # expected output file name
+          outnames[outname] ||= i  # index of the first task in the tasklist, resulting in output file name 'outname'
+          outnames[outname] < i    # the file name could be generate both by  i-th and one of previous tasks
+        end
+
+        if !t.nil?
+          t_1                 = tasklist[outnames[outname]]
+          input_userfile_id_1 = t_1.invoke_params[fileinputid]     # input file id resulting in duplicated output file name
+          input_userfile_1    = Userfile.find(input_userfile_id_1)
+
+          msg = ":BoutiquesOutputFilenameRenamer module require unique output names for batch tasks," +
+                "yet input files '#{input_userfile.name}' and '#{input_userfile_1.name}' result in the same output file " +
+                " '#{outname}' for output file pattern '#{original_outname_pattern}'."
+
+          self.errors.add(outnameinputid,  ": Add a pattern that may result in different files names, such a {full} or {task} to '#{outname_pattern}' ")
+          t.errors.add(outnameinputid, msg)
+        end
+      end
+    end
+    tasklist
+  end
+
+
   ##################################################
   # Cluster side overrides
   ##################################################