diff -r b1a51285de7e -r 7f3f01dfe738 testing/collatz_test.sh
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/collatz_test.sh	Wed Nov 08 13:57:13 2017 +0000
@@ -0,0 +1,102 @@
+#!/bin/bash
+
+# to make the script fail safely
+set -euo pipefail
+
+
+out=${1:-output}
+
+echo "" > $out
+
+echo "Below is the feedback for your submission collatz.scala" >> $out
+echo "" >> $out
+
+
+# compilation tests
+
+function scala_compile {
+  (ulimit -t 30 -m 1024000 ; scala "$1" 2>> $out 1>> $out) 
+}
+
+# functional tests
+
+function scala_assert {
+  (ulimit -t 30 -m 1024000 ; scala -i "$1" "$2" -e "" 2> /dev/null 1> /dev/null)
+}
+
+# purity test
+
+function scala_vars {
+   (egrep '\bvar\b|\breturn\b|\.par|ListBuffer|mutable' "$1" 2> /dev/null 1> /dev/null)
+}
+
+
+# var, .par return, ListBuffer test
+#
+echo "collatz.scala does not contain vars, returns etc?" >> $out
+
+if (scala_vars collatz.scala)
+then
+  echo "  --> fail" >> $out
+  tsts0=$(( 1 ))
+else
+  echo "  --> success" >> $out
+  tsts0=$(( 0 )) 
+fi
+
+### compilation test
+
+
+if  [ $tsts0 -eq 0 ]
+then 
+  echo "collatz.scala runs?" >> $out
+
+  if (scala_compile collatz.scala)
+  then
+    echo "  --> success" >> $out
+    tsts=$(( 0 ))
+  else
+    echo "  --> scala did not run collatz.scala" >> $out
+    tsts=$(( 1 )) 
+  fi
+else
+  tsts=$(( 1 ))     
+fi
+
+### collatz tests
+
+if [ $tsts -eq 0 ]
+then
+  echo "collatz.scala tests:" >> $out
+  echo "  collatz(1) == 0,1 or 4" >> $out
+  echo "  collatz(6) == 9" >> $out
+  echo "  collatz(9) == 20" >> $out
+
+  if (scala_assert "collatz.scala" "collatz_test1.scala")
+  then
+    echo "  --> success" >> $out
+  else
+    echo "  --> one of the tests failed" >> $out
+  fi
+fi
+
+### collatz-max tests
+
+if [ $tsts -eq 0 ]
+then
+  echo "  collatz_max(10) == (20, 9)" >> $out
+  echo "  collatz_max(100) == (119, 97)" >> $out
+  echo "  collatz_max(1000) == (179, 871)" >> $out
+  echo "  collatz_max(10000) == (262, 6171)" >> $out
+  echo "  collatz_max(100000) == (351, 77031)" >> $out
+  echo "  collatz_max(1000000) == (525, 837799)" >> $out
+
+  if (scala_assert "collatz.scala" "collatz_test2.scala") 
+  then
+    echo "  --> success" >> $out
+  else
+    echo "  --> one of the tests failed" >> $out
+  fi
+fi
+
+